714 results on '"Ursa Major"'
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2. Veneration of Ursa Major among the Oirats and Kalmyks: Ancient Beliefs and Later Buddhist Additions. Part 2
- Author
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Elza P. Bakaeva
- Subjects
ursa major ,mongolic peoples ,oirats ,kalmyks ,myths ,beliefs ,archaic calendar ,rites ,History (General) ,D1-2009 ,Oriental languages and literatures ,PJ - Abstract
Introduction. Ursa Major is the constellation most venerated by Mongolic peoples. Goals. The article seeks to examine related beliefs traced in folklore and collected field data, reveal key mythological characteristics, and cast light upon diachronous layers in the beliefs of Kalmyks and Oirats (Western Mongols). So, the work aims at analyzing basic Kalmyk and Oirat folklore plots dealing with origins of the Great Bear in comparison to those of other Mongolic cultures; and at examining the concept of Ursa Major against the background of some calendar rites and revered mythological images with due regard of contemporary ceremonies addressed to the constellation. Materials. The paper analyzes folklore and ethnographic materials. Results. Part 1 of the article identifies main variants of mythological texts about Ursa Major (Mong. Долоон бурхан, Долоон өвгөн, Kalm. Долан бурхн, Долан одн) existing in Kalmyk and Oirat discourses, comparing the latter to myths of other Mongolic populations. It shows that basically the myths narrate about seven male characters (siblings, sworn brothers, or thieves) or an ox-man, though etymology of terms may tie the constellation (its emergence) to the archaic plot of day and night alternation as a chase of shedeer, and the solar theme at large. Part 2 further analyzes Ursa Major-related beliefs and compares the latter to some calendar rites and mythological images revered in Kalmyk and Oirat culture. The paper informs that the constellation was sometimes referred to by the Oirats as ‘Seven Maral Deer’ (Oir. Долоон марал), which implies our analysis may extend to the legend of how the heavenly hunter pursued a flock of she-deer. The Oirat oral tradition believes that both the characters of Ursa Major stories and Khukhedei Mergen the Hunter (whose chase made three she-deer turn into the three stars of Orion’s Belt therefore referred to by the Mongols as ‘Three She-Deer’, Mong. Гурван марал, Kalm. Һурвн марл) can be considered masters of the two horses tied to the ‘Golden Pole’ (i.e. Pole Star) — two stars of Ursa Minor. Oirats and Kalmyks also associate Ursa Major with thawing weather, protection of children, livestock (from wolves), and increase of its numbers, remission of sins — similar functions attributed to the White Old Man (Kalm. Цаhан аав) revered by the Oirats as the Lord of the Altai, while Kalmyks tend to view him as a protector deity of the nation, one of his manifestations being that of the Lord of the Year (Kalm. Җилин эзн). The article also analyzes contemporary Buddhist rites dealing with Ursa Major among Mongolic populations.
- Published
- 2020
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- View/download PDF
3. Veneration of Ursa Major among the Oirats and Kalmyks: Ancient Beliefs and Later Buddhist Additions. Part 1
- Author
-
Elza P. Bakaeva
- Subjects
ursa major ,mongolic peoples ,oirats ,kalmyks ,myths ,beliefs ,archaic calendar ,rites ,History (General) ,D1-2009 ,Oriental languages and literatures ,PJ - Abstract
Introduction. Ursa Major is the constellation most venerated by Mongolic peoples. Goals. The article seeks to analyze related beliefs traced in folklore and collected field data, reveal key mythological characteristics, and cast light upon diachronous layers in the beliefs of Kalmyks and Oirats (Western Mongols). So, the work aims at analyzing basic Kalmyk and Oirat folklore plots dealing with origins of the Great Bear in comparison to those of other Mongolic cultures; and at examining the concept of Ursa Major against the background of some calendar rites and revered mythological images with due regard of contemporary ceremonies addressed to the constellation. Materials. Part One investigates folklore, ethnographic, and linguistic sources involved, thus focusing on the first objective declared. Part Two to be published in the next issue of the journal shall deal with the remaining tasks. Results. The paper identifies main variants of mythological texts about Ursa Major (Mong. Долоон бурхан, Долоон өвгөн, Kalm. Долан бурхн, Долан одн) existing in Kalmyk and Oirat discourses, comparing the latter to myths of other Mongolic populations. Basically, the myths narrate about seven male characters (siblings, sworn brothers, or thieves) or an ox-man. The Kalmyk plot of thieves is somewhat unique in Mongolic traditions, being rather typical for Turkic ones. The plot of ox-man Masn Mirü (or Massang) was borrowed from Tibet, though etymology of terms may tie the constellation (its emergence) to the archaic plot of day and night alternation as a chase of she-deer, and the solar theme at large.
- Published
- 2020
- Full Text
- View/download PDF
4. MELISSA IWAI.
- Author
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Howell, Raven
- Subjects
CHILDREN'S literature writing ,WOMEN illustrators ,ILLUSTRATED children's books ,URSA Major - Abstract
The article presents an interview with children's book author/illustrator Melissa Iwai who discusses about her journey of authoring/illustrating so many delightful children's book; her challenging experience of being asked to illustrate the Big Dipper(constellation) using eight stars since almost all maps of the constellations depict it having seven stars; and her favorite children's illustrators such as Richard Scarry, Garth Williams, Maurice Sendak, Gyo Fujiwara, and Remy Charlip.
- Published
- 2022
5. THE EVOLUTION OF MYTHS.
- Author
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d’Huy, Julien
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MYTHOLOGY , *CONTENT analysis , *CROSS-cultural studies , *URSA Major , *URSA Minor , *POLYPHEMUS (Greek mythology) , *CROW (North American people) - Abstract
The article focuses on research into the evolution of myths among differing cultures. It states a comparison of 47 culturally distinct myths concerning the Big Dipper and the Little Dipper constellations, known as the Cosmic Hunt myths, shows how mytheme analysis can determine the relatedness of stories and divergent points for each myth. It talks about similarities of the Greek myth on Polyphemus in Homer's "Odyssey" resembled tales of the trickster Crow among Algonquin myths.
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- 2016
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6. ҚАЗАҚ ХАЛҚЫНЫҢ АСПАН ӘЛЕМІН БАҚЫЛАУ АРҚЫЛЫ АУА РАЙЫН БОЛЖАУДАҒЫ ХАЛЫҚТЫҚ БІЛІМДЕРІ
- Author
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Эшбекова, Г. У.
- Abstract
Copyright of Journal of History / Habaršy Tarihi Seriâsy is the property of Al-Farabi Kazakh National University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2021
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7. THE SEVEN SPIRITS ... IN THE ANCIENT EGYPTIAN RELIGION.
- Author
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Ahmed, Radwan 'Abd 'El-Rady Sayed
- Subjects
EGYPTIAN religion ,COFFINS ,OSIRIS (Egyptian deity) ,VOYAGES to the otherworld ,URSA Major - Published
- 2021
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8. STORIES IN THE STARS.
- Author
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PRICE, RYAN LEE
- Subjects
ASTERISMS (Astronomy) ,ZODIAC ,CONSTELLATIONS ,IVORY carving ,URSA Major - Published
- 2021
9. March: The Plane Truth
- Author
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Carter, Jamie and Carter, Jamie
- Published
- 2015
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10. Il motivo delle sette stelle nell' Apocalisse e l'immaginario greco-romano.
- Author
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Cigaina, Lorenzo
- Subjects
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STOICISM , *JEWISH literature , *FIGURES of speech , *APOCRYPHAL Gospels , *ANGELS , *HEBREW literature ,ROMAN emperors - Abstract
At the beginning of the Apocalypse the figure of Jesus Christ appears bright like the sun in its full shine, while holding seven stars in his right hand (Ap 1,16; cf. 2,1; 3,1). The meaning of the vision is explained a little further (Ap 1,20): the seven stars symbolize the angels of the seven churches of Asia, recipients of seven letters. Seven stars appear occasionally in the Bible and in late apocryphal Jewish literature with various meanings. Their placement in the hand of Christ, however, has no precedent in these traditions, while occurs in the Greco-Roman iconography, where the motif is associated with Zeus on Crete or Jupiter in Rome and with the deified Roman emperors, which are considered as equivalent in the role of rulers of the cosmos. The seven stars of these mythological accounts are identifiable with the Septem Triones, the constellation of Ursa Major. In Stoic philosophy and later in the imperial apotheosis they indicate the highest point of the sky that never sets and revolve about the axis of the world governed by the Logos (identified with Zeus and Jupiter, too). The cycle of death and rebirth of the Cretan Zeus as well as the light of Sun-Apollo, both associable with the risen Christ of the apocalyptical vision, dialogue further with the Hellenistic-Roman figurative language. Christ appears then as a new, complete synthesis of previous experiences and at the same time he overcomes them: as the true king at the top of the cosmos he guides history and, in it, the essential action of the Church. [ABSTRACT FROM AUTHOR]
- Published
- 2020
11. The origin of the Greek constellations.
- Author
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Schaefer, Bradley E.
- Subjects
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CONSTELLATIONS , *CONSTELLATIONS in art , *GREEK astrology , *HEBREW astrology , *URSA Major , *BOUNDARY stones , *ASTRONOMY , *HISTORY , *RELIGION - Abstract
The article focuses on the history of constellations. The author describes how the Greeks, Basques, Hebrews, many tribes in Siberia, and North American tribes were aware of the Great Bear, or Ursa Major, constellation. Also mentioned are Assyrian priests, the MUL.APIN tablets, Greek scholars, boundary stones, and the discoveries of modern scientists. INSETS: PRECESSION: The Shifting Stars;THE FARNESE ATLAS.
- Published
- 2006
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12. Sky Delights: A Tiger with Deep Sky Spots.
- Author
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Streicher, Magda
- Subjects
- *
ASTERISMS (Astronomy) , *AURIGA (Constellation) , *URSA Major , *BINARY stars , *SPIRAL galaxies , *ASTRONOMICAL observations - Published
- 2018
13. Molecular Lines of CO Isotopes of the High Galactic Latitude Cloud HSVMT27.
- Author
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He, Zhi-hong, Xu, Ye, Yang, Ji, Lu, Deng-rong, Du, Xin-yu, Li, Fa-cheng, and Yan, Qing-zeng
- Subjects
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STAR formation , *LOCAL thermodynamic equilibrium , *CARBON monoxide , *RADIOISOTOPES , *STELLAR dynamics , *URSA Major - Abstract
A study on the CO 12 , CO 13 , and C 18 O lines of the high Galactic latitude cloud HSVMT 27, located in Ursa Major, was conducted. A relatively low CO 12 excitation temperature was found. While some C 18 O emissions were detected, they were too weak to be mapped. With the spatial resolution of 0.08 pc and the velocity resolution of 0.17 km·s −1 , 26 CO 13 cores were identified in the dense regions. All the local thermodynamic equilibrium masses of these cores are less than their Virial masses, ranging in 0.5–10 M ⊙ , and have no infrared point sources associated with them. Overall, the data indicate that there is no recent or ongoing star formation in this cloud. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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14. Three leaps of the gazelle.
- Author
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O'Meara, Stephen James
- Subjects
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CONSTELLATIONS , *URSA Major , *EXTRAGALACTIC distances , *GALAXIES , *STARS - Abstract
The article focuses on the three leaps of the Springs of the Gazelle Nu (ν) and Xi (ξ) Ursae Majoris (marking the Bear's right hind foot) comprise the First Spring; Lambda (λ) and Mu (μ) UMa (marking the Bear's left hind foot) comprise the Second Spring and Iota (ι) and Chi (χ) UMa (marking the Bear's right front paw) comprise the Third Spring. Topics include the first leap is NGC 3414, extragalactic "spark," and the stars of Gazelle reassembled into Leo Minor the Little Lion constellations.
- Published
- 2019
15. The Discovery of a Gravitational Lens.
- Author
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Chaffee Jr., Frederic H.
- Subjects
QUASARS ,GRAVITATIONAL lenses ,METEORS ,ASTRONOMY ,URSA Major - Abstract
The article focuses on the discovery of Quasars through a gravitational lens. A recent discovery found out to be a single quasar. Quasars are uniformly distributed throughout the sky, there are already 1,500 known quasars. A single quasar is determined on the average of almost 30 square degrees, about a size of a Big Dipper.
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- 1980
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16. Astronomy of tribals of central India.
- Author
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Vahia, M. N. and Halkare, Ganesh
- Subjects
- *
TRIBES , *ASTRONOMICAL observations , *INTELLECTUAL development , *URSA Major ,LUNAR atmosphere - Abstract
A summary of the astronomical beliefs of four tribes Gond, Banjara, Kolam and Korku from Nagpur region of Maharashtra has been presented. Primary conclusions are that the tribals are mainly focused on the winter sky with Big Dipper (Saptarshi), the Orion region including Orion, Taurus, Auriga, Gemini, Canis Major and Pleiades. They are also quite conscious of the Southern Cross (Crux) and the region around it. Many tribes are aware of Scorpius but are often unable to define its location in the sky. Gonds are aware of the Great Square of Pegasus and of Leo. We discuss these beliefs in the background of the region of the sky that occupies them and the similarity and differences in their beliefs of these regions. We then summarize the results in the general framework of human intellectual development and the environment in which they live. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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17. AE Ursae Majoris - a δ Scuti star in the Hertzsprung Gap.
- Author
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Jia-Shu Niu, Jian-Ning Fu, Yan Li, Xiao-Hu Yang, Weikai Zong, Hui-Fang Xue, Yan-Ping Zhang, Nian Liu, Bing Du, and Fang Zuo
- Subjects
- *
STARS , *LUMINOSITY , *SPECTRUM analysis , *PHOTOMETRY , *URSA Major - Abstract
We analyse the photometric data and spectroscopic data collected on the δ Scuti star AE Ursae Majoris (AE UMa). The fundamental and the first overtone frequencies are confirmed as f0 = 11.625 60 c d-1 and f1 = 15.031 24 c d-1, respectively, from the frequency content by analysing light curves over 40 nights, spanning from 2009 to 2012. Additionally, another 37 frequencies are identified as either the harmonics or the linear combinations of the fundamental and the first overtone frequencies, among which 25 are newly detected. The rate of period change of the fundamental mode is determined as (1/P0)(dP0/dt) = 5.4(±1.9) x 10-9 yr-1 as revealed from the O - C diagram based on the 84 newly determined times of maximum light combined with those derived from the literature. The spectroscopic data suggest that AE UMa is a Population I δ Scuti star. With these physical properties, we perform theoretical explorations based on the stellar evolution codeMESA on this target, considering that the variation of pulsation period is caused by secular evolutionary effects. We finally constrain AE UMa with physical parameters as follows: mass of 1.805 ± 0.055 M⊙, radius of 1.647 ± 0.032 x 1011 cm, luminosity of 1.381 ± 0.048(log L/L⊙) and age of 1.055 ± 0.095 x 109 yr. AE UMa can be the (Population I) δ Scuti star that locates just after the second turn-off of its evolutional track leaving the main sequence, a star in the phase of the Hertzsprung Gap with a helium core and a hydrogen-burning shell. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
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18. Mehr zur Astronomie in den homerischen Epen
- Author
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Otta Wenskus
- Subjects
Literature ,Linguistics and Language ,Ursa Major ,History ,biology ,business.industry ,Ursa ,Circumpolar star ,biology.organism_classification ,Language and Linguistics ,Meaning (existential) ,Classics ,business ,Big Dipper ,Constellation - Abstract
While Iliad 10,251–253 has often been translated correctly, Odyssey 12,312 (≈14,483) has not fared nearly as well, although the meaning is basically the same. Whether this means that the author of Iliad 10 improved on the Odyssey or not, Odyssey 12,312 is best understood as meaning “But when it was the third part of the night and the stars had already completed a considerable part of their paths.” In the second part of this article it is argued that τeίρeα in Iliad 18,485 means not all stars or constellations, but just the most conspicuous ones, which explains why in Iliad 18,487–489 = Odyssey 5,273–275 it is asserted that only the Great Bear is barred from bathing in the ocean, a problem already debated in antiquity: the seven stars of Ursa maior forming the Big Dipper constitute the only conspicuous group of stars which was circumpolar in archaic Greece. The latter theory, an overlooked explanation of Walter Leaf, can be supported by further evidence.
- Published
- 2021
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19. ON EARTH AS IT IS IN HEAVEN.
- Author
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LYDGATE, ANTHONY
- Subjects
COSMOLOGY in art ,URSA Major - Published
- 2019
20. Apex and Kinematical Structure of Castor and Ursa Major Moving Stellar Groups
- Author
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W. H. Elsanhoury
- Subjects
Physics ,Ursa Major ,010308 nuclear & particles physics ,Space and Planetary Science ,0103 physical sciences ,Structure (category theory) ,Astronomy and Astrophysics ,Astrophysics ,UVW mapping ,Stellar classification ,010303 astronomy & astrophysics ,01 natural sciences ,Vertex (geometry) - Abstract
Based on space velocity components UVW and using a recent dataset for Castor and Ursa Major moving groups, we compute the apex position with two methods. Classical convergent procedures give (Acp, Dcp) = (80$$_{.}^{\circ}$$7830, –17$$_{.}^{\circ}$$2598; Castor, 298$$_{.}^{\circ}$$334, –34$$_{.}^{\circ}$$6405; UMa) for Castor and Ursa Major groups. According to the AD-map method we deduce the apex position (A0, D0) = (79$$_{.}^{\circ}$$5514, –17$$_{.}^{\circ}$$3948; Castor, 304$$_{.}^{\circ}$$767, ‒35$$_{.}^{\circ}$$2045; UMa) for these two objects. These results are in good agreement with other published coordinated. Also, we calculate all parameters with a model of stream velocity ellipsoidal motions, which reveals inner kinematical structure. Finally, we consider the intrinsic variations considered with late-type moving groups (streams) for the longitude of the vertex versus temperature (spectral types).
- Published
- 2020
- Full Text
- View/download PDF
21. Startup Raises $138 Million To Help U.S. Rebuild Missile Arsenal Depleted By Ukraine.
- Author
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Bogaisky, Jeremy
- Subjects
ARSENALS ,WAR ,NEW business enterprises ,ROCKET engines - Abstract
The Pentagon is looking to replenish stockpiles of major weapons to prepare for a potential war with China. That could be lucrative for rocket-engine maker Ursa Major. [ABSTRACT FROM AUTHOR]
- Published
- 2023
22. Chemical tagging of the Ursa Major moving group.
- Author
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Tabernero, H. M., Montes, D., González Hernández, J. I., and Ammler-von Ei, M.
- Subjects
- *
URSA Major , *CONSTELLATIONS , *OPEN clusters of stars , *STELLAR atmospheres , *COOL stars (Astronomy) - Abstract
Context. Stellar kinematic groups are kinematically coherent groups of stars that might have a common origin. These groups spread through the Galaxy over time owing to tidal effects caused by Galactic rotation and disk heating. However, the chemical information survives these processes. Aims. The information provided by analysis of chemical elements can reveal the origin of these kinematic groups. Here we investigate the origin of the stars that belong to the Ursa Major (UMa) moving group (MG). Methods. We present high-resolution spectroscopic observations obtained from three different spectrographs of kinematically selected FGK stars of the Ursa Major moving group. Stellar atmospheric parameters (Teff, log g, ξ, and [Fe/H]) were determined using our own automatic code (StePar), which makes use of the sensitivity of iron equivalent widths (EWs) measured in the spectra. We critically compared the StePar results with other methods (Te values derived using the infrared flux method (IRFM) and log g values based on Hipparcos parallaxes). We derived the chemical abundances of 20 elements and their [X/Fe] ratios for all stars in the sample. We performed a differential abundance analysis with respect to a reference star of the UMa MG (HD 115043). We also carried out a systematic comparison of the abundance pattern of the Ursa Major MG and the Hyades SC with the thin disk stellar abundances. Results. Our chemical tagging analysis indicates that the Ursa Major MG is less affected by field star contamination than other moving groups (such as the Hyades SC). We find a roughly solar iron composition [Fe/H] = 0.03 ± 0.07 dex for the finally selected stars, whereas the [X/Fe] ratios are roughly subsolar except for super-solar Barium abundance. Conclusions. We conclude that 29 out of 44 (i.e., 66%) candidate stars have similar chemical compositions. In addition, we find that the abundance pattern of the Ursa Major MG might be marginally different from that of the Hyades SC. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
23. The photometric investigation of the newly discovered W UMa type binary system GSC 03122-02426.
- Author
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X., Zhou, S.-B., Qian, J.-J., He, J., Zhang, and B., Zhang
- Subjects
- *
ASTRONOMICAL photometry , *BINARY systems (Astronomy) , *ECLIPSING binaries , *ASTROPHYSICS , *ASTRONOMICAL research , *URSA Major - Abstract
The B V R c I c bands light curves of the newly discovered binary system GSC 03122-02426 are obtained and analyzed using the Wilson–Devinney (W–D) code. The solutions suggest that the mass ratio of the binary system is q = 2.70 and the less massive component is 422 K hotter than the more massive one. We conclude that GSC 03122-02426 is a W-subtype shallow contact (with a contact degree of f = 15.3 % ) binary system. It may be a newly formed contact binary system which is just under geometrical contact and will evolve to be a thermal contact binary system. The high orbital inclination ( i = 81 . 6 ∘ ) implies that GSC 03122-02426 is a total eclipsing binary system and the photometric parameters obtained by us are quite reliable. We also estimate the absolute physical parameters of the two components in GSC 03122-02426, which will provide fundamental information for the research of contact binary systems. The formation and evolutionary scenario of GSC 03122-02426 is discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
24. SKY BEAR RESEARCH: IMPLICATIONS FOR "CULTURAL ASTRONOMY".
- Author
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Frank, Roslyn M.
- Subjects
- *
ARCHAEOASTRONOMY , *ETHNOASTRONOMY , *ETHNOLOGY , *MNEMONICS , *BELIEF & doubt , *URSA Major - Abstract
This chapter examines research carried out to date on the Sky Bear and seeks to demonstrate the implications of this line of research for "cultural astronomy". It begins by reviewing research that has been done cross-culturally on bear ceremonialism, focusing on the role of circumpolar stars, Dipper stars and stars adjacent to them, and how they came to be integrated, cognitively, into an over-arching cosmology shared by different hunter-gatherer populations across the N. Hemisphere. Next, using three mutually reinforcing ethnographic datasets, the manner in which, specifically in Europe, this archaic worldview, characterized by embodied reciprocity, allowed humans, animals and nature to be bound together. The cosmology, grounded in the belief that humans descended from bears, integrated skyscape and landscape into a single interlocking reality. Furthermore, the worldview can be understood as embodying a "relational epistemology" or "relational ecology". This more culturally-informed approach coincides with the goals of "cultural astronomy" as well as the methodology and goals of the emerging field of archaeological ethnography. The reasons that these particular sky resources were chosen to project this set of spirtual beliefs skyward are also addressed. In the final section I suggest that the skyscape acts a kind of mnemonic device. As such, it is a cognitive resource, readily available to the social collective in question, which can act as a repository for past beliefs. Anchoring key components of a cosmology in the stars above allows the resulting skyscape to act as an enduring "memory bank". In short, the datasets analyzed facilitate the reconstruction of a European-wide ethno-cultural substrate that points to an archaic relational cosmovision and the belief that humans descended from bears as well as providing evidence for the way that skyscape and landscape were integrated into this cosmology. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
25. THE BEAR AND THE YEAR: ON THE ORIGIN OF THE FINNISH LATE IRON AGE FOLK CALENDAR AND ITS CONNECTION TO THE BEAR CULT.
- Author
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Ridderstad, Marianna P.
- Subjects
- *
LUNAR calendar , *IRON Age , *PALEOLITHIC Period , *NEOLITHIC Period , *FINNO-Ugrians - Abstract
The role of the bear as a calendric deity among the Finnic and Finno-Ugric peoples echoes it general importance in all aspects of the northern cultures. The Finnic peoples divided their year into four parts by two Bear Days in January and July, and the Summer and Winter Nights between those. In the earliest wooden folk calendars in Finland that can be traced to the 13th century, those calendric marker days had already been fixed into the Julian year, but in earlier times, they would have been determined by a lunisolar or lunar calendar. The calendric system of the late Iron Age Finns and other Finnic peoples was lunisolar with intercalation, and its structure and main marker days indicate that it had several layers of different age: the Bear Year' seasonal division, the idea of the eight-divided solar year-probably of Indo-European origin-, and a basic lunisolar intercalation calendar with twelve or thirteen months. The Finnish celestial lore related to the bear can also be connected to the seasonal positions of the Big Dipper asterism. While the seasonal calendric significance of the bear in Eurasian cultures is probably very ancient, possibly even Paleolithic, the connection of the Finnic Bear Year seasonal division and lunisolar calendars can be traced at least to the late Neolithic period. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
26. SKY SIMULATIONS FOR THE PALAEOLITHIC EPOCH.
- Author
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Antonello, Elio
- Subjects
- *
PALEOLITHIC Period , *CONSTELLATIONS , *ETHNOLOGY , *COMPUTER simulation , *ASTRONOMICAL software , *ARCHAEOASTRONOMY - Abstract
The simulations of the sky for the very far past are briefly discussed, and a possible application to the study of the Bear constellations, in particular for the epoch of the last glacial maximum, is presented; reference is made to the different length of seasons, climate and environment. Many ethnographic studies described the special relationship between men and bears, in connection also with a cosmic hunt, and it may be possible that such a relation dates back to the Palaeolithic epoch. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
27. Five Miles until Friday? Addressing Misunderstandings of Light-Years.
- Author
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Brown, Katrina, Brown, Todd, and Hardy, Wendy
- Subjects
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LIGHT-year , *FIFTH grade (Education) , *URSA Major , *ORION (Constellation) , *ASTROPHYSICS study & teaching - Abstract
In this fourth and fifth grade activity, students become comfortable with the concept that light-years are a measure of distance, not time, and discover how we are looking back in time when we look at stars. Since the enormous distances in space can make astronomical studies even more confusing, students explore the meaning of a light-year by first examining a unit on a smaller scale: the person-walking-week. Students determine how many kilometers a person can walk in a week and then use this unit of measurement to determine distances between cities. Once comfortable with the idea that this is a unit of distance, students then tackle the light-year and examine the stars in the Big Dipper and Orion. Using known distances to the stars, they determine when light seen today from those stars originally began its journey through space. Cross-curricular connections can then be easily made with topics in history. [ABSTRACT FROM PUBLISHER]
- Published
- 2015
- Full Text
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28. Wide sub-stellar companions—Something of a rarity also around Ursa Major group members?
- Author
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Eiff, M. Ammler-von, Bedalov, A., Mugrauer, M., Neuhäuser, R., and Guenther, E. W.
- Subjects
- *
URSA Major , *CONSTELLATIONS , *AGE of stars , *STELLAR orbits , *IMAGING systems in astronomy - Abstract
The Ursa Major group is the closest moving group with its densest part being located in the direction of the Big Dipper constellation at a distance of about 25 pc. In spite of the small distance, the relatively young age of 200–600 Myrs, and the on average high proper motions, this sample of stars has not yet been addressed as a whole by direct imaging studies of sub-stellar companions in wide orbits. We searched the fields around more than 20 nearby Ursa Major group members at a distance of less than 30 pc using adaptive optics and coronography with NAOS/CONICA at the ESO VLT, Chile. Many sub-stellar companion candidates were detected in the first epoch imaging in 2003/2004. However the second epoch imaging in 2005/2006 revealed that none of these displayed common proper motion so that the candidates turned out to be unrelated objects. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
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29. Prologue.
- Author
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Cotterill, Rodney
- Abstract
Stand still you ever-moving spheres of heaven, that time may cease, and midnight never come. There is broad scientific agreement that the Universe came into existence about 13 700 000 000 years ago, as a result of the largest-ever explosion. In the briefest of instants, the explosion created all the matter and energy that has ever existed, and although matter and energy are interconvertible, as Albert Einstein's special theory of relativity tells us, their sum has remained constant ever since. Fred Hoyle referred to this cataclysmic event as the big bang – facetiously in fact, because he advocated the now-defunct rival idea of continuous creation. In 1948, Hoyle, Hermann Bondi and Thomas Gold had put forward the idea that the Universe is in a steady state, that it had no beginning, and that it will have no end. There is now strong evidence that the big bang did take place, as first surmised by Georges Lemaître in 1927, and thus that the Universe certainly did have a beginning. It remains a moot point, however, as to whether it will have an end. One might speculate as to what was present in the cosmos before the primordial explosion, but Stephen Hawking has argued that such a question would be incorrectly posed, and therefore futile. According to his theory, the big bang created time itself, and it thus coincided with what could be called a pole in time. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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- View/download PDF
30. All About Asterisms: THESE STAR PATTERNS ARE THE KEYS THAT UNLOCK THE CONSTELLATIONS.
- Author
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KING, BOB
- Subjects
ASTERISMS (Astronomy) ,CONSTELLATIONS ,BINOCULARS ,TELESCOPES ,URSA Major - Abstract
The article discusses asterisms. Topics discussed include the Big Dipper as an asterism of seven bright stars, naked-eye asterisms such as large seasonal asterisms, cross-border asterisms and archaic asterisms; and observing patterns using binoculars or a telescope. It presents map featuring asterisms.
- Published
- 2017
31. Small Scope Asterisms.
- Author
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STRATTON, TROY
- Subjects
- *
ASTERISMS (Astronomy) , *CONSTELLATIONS , *STAR clusters , *CASSIOPEIA (Constellation) , *URSA Major - Abstract
The article offers information on asterisms as long-lived patterns, sometimes existing in a single constellation and sometimes made from parts of several constellations. Levy 384 in Puppis seems like an open star cluster, but a non-distinct asterism as the stars are not physically related or gravitationally bound to one another. The W of Cassiopeia and the Big Dipper are two well-known asterisms where the forms can be picked out by looking up on a clear night.
- Published
- 2016
32. Our Surprisingly Ancient "Greek" Constellations.
- Author
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CROSSEN, CRAIG
- Subjects
- *
CONSTELLATIONS , *ENLIL (Assyro-Babylonian deity) , *URSA Major , *SCIMITARS , *PERSEUS (Greek mythology) , *SUMERIANS , *HISTORY - Abstract
The article focuses on the history of Greek constellations. Topics discussed include Great Bear constellation which is also called as the Wagon of the North; a special relationship between Enlil, the god of the northern constellations and the prominent celestial Wagon; Scimitar of Perseus which was named as Gam, and a constellation called Shugi placed by the Sumerians.
- Published
- 2016
33. The properties of early-type galaxies in the Ursa Major cluster.
- Author
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Pak, Mina, Rey, Soo-Chang, Lisker, Thorsten, Lee, Youngdae, Kim, Suk, Sung, Eon-Chang, Jerjen, Helmut, and Chung, Jiwon
- Subjects
- *
GALAXY clusters , *EXTRAGALACTIC distances , *MONOCHROMATIC light , *DWARF galaxies , *URSA Major ,VIRGO Cluster - Abstract
Using SDSS-DR7 and NASA/IPAC Extragalactic Database spectroscopic data, we identify 166 galaxies as members of the Ursa Major cluster with Mr < −13.5 mag. We morphological classify all galaxies by means of carefully inspecting g-, r-, i-band colour and monochromatic images. We show that the Ursa Major cluster is dominated by late-type galaxies, but also contains a significant number of early-type galaxies, particularly in the dwarf regime. We present further evidence for the existence of several subgroups in the cluster, consistent with previous findings. The early-type fraction is found to correlate with the mass of the subgroup. We also investigate environmental effects by comparing the properties of the Ursa Major early-type dwarf galaxies to those of the Virgo cluster. In contrast to the Virgo, the red sequence of the Ursa Major cluster is only sparsely populated in the optical and ultraviolet colour–magnitude relations. It also shows a statistically significant gap between −18 < Mr < −17 mag, i.e. the Ursa Major cluster lacks early-type dwarf galaxies at the bright end of their luminosity function. We discover that the majority of early-type dwarf galaxies in the Ursa Major cluster have blue cores with hints of recent or ongoing star formation. We suggest that gravitational tidal interactions can trigger central blue star-forming regions in early-type dwarfs. After that, star formation would only fade completely when the galaxies experience ram-pressure stripping or harassment, both of which are nearly absent in the Ursa Major cluster. [ABSTRACT FROM PUBLISHER]
- Published
- 2014
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34. The Ursa Major Association of Galaxies. VI: A relative dearth of gas-rich dwarf galaxies
- Author
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Martin Zwaan, Neil Trentham, J. M. van der Hulst, R. B. Tully, Marc Verheijen, E. Busekool, Kapteyn Astronomical Institute, and Astronomy
- Subjects
Physics ,Ursa Major ,010308 nuclear & particles physics ,HIPASS ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,galaxies: dwarf ,01 natural sciences ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Cover (topology) ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,galaxies: clusters: individual: Ursa Major ,010303 astronomy & astrophysics ,Dwarf galaxy - Abstract
We determined the HI mass function of galaxies in the Ursa Major association of galaxies using a blind VLA-D array survey, consisting of 54 pointings in a cross pattern, covering the centre as well as the outskirts of the Ursa Major volume. The calculated HI mass function has best-fitting Schechter parameters {\theta}^* = 0.19+/-0.11 Mpc^{-3}, log(M^*_{HI}/M_{\odot}) = 9.8+/-0.8 and {\alpha} = -0.92+/-0.16. The high-mass end is determined by a complementary, targeted WSRT survey, the low-mass end is determined by the blind VLA survey. The slope is significantly shallower than the slopes of the HIPASS ({\alpha} = -1.37+/-0.03+/-0.05) and ALFALFA ({\alpha} = -1.33+/-0.02) HI mass functions, which are measured over much larger volumes and cover a wider range of cosmic environments: There is a relative lack of low HI mass galaxies in the Ursa Major region. This difference in the slope strongly hints at an environmental dependence of the HI mass function slope., Comment: 19 pages, 15 figures. Accepted for publication in MNRAS
- Published
- 2020
35. The orbital evolution of UFDs and GCs in an evolving Galactic potential
- Author
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Aaron D. Ludlow, Kenji Bekki, and Benjamin M Armstrong
- Subjects
Physics ,Orbital elements ,Ursa Major ,010308 nuclear & particles physics ,Milky Way ,Local Group ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Space and Planetary Science ,Globular cluster ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Galaxy formation and evolution ,Astrophysics::Earth and Planetary Astrophysics ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Dwarf galaxy - Abstract
We use the second Gaia data release to investigate the kinematics of 17 ultra-faint dwarf galaxies (UFDs) and 154 globular clusters (GCs) in the Milky Way, focusing on the differences between static and evolving models of the Galactic potential. An evolving potential modifies a satellite's orbit relative to its static equivalent, though the difference is small compared to existing uncertainties on orbital parameters. We find that the UFD Bo\"otes II is likely on its first passage around the Milky Way. Depending on the assumed mass of the Milky Way, the UFDs Triangulum II, Hydrus I, Coma Berenices, Draco II, and Ursa Major II, as well as the GC Pyxis, may also be on first infall so may be useful for constraining the mass of the Galaxy. We identify a clear kinematic distinction between metal-rich (${\rm [Fe/H]}>-1.1$) and metal-poor GCs (${\rm [Fe/H]}\leq-1.1$). Although most metal-rich clusters occupy predominately prograde orbits, with low eccentricities ($e\approx 0.35$) and similar specific angular momenta and orbital planes as the Galactic disc, 7 show potentially retrograde orbits, the origin of which is unclear. Metal-poor clusters have more diverse orbits, higher eccentricities ($e\approx 0.65$), and half have orbital planes offset from the disc by 60 to 120 degrees. The UFDs have similar $\theta$ and $\phi$ to the metal-poor GCs, suggesting a similar origin. We provide a catalogue of orbital parameters for UFDs and GCs for two different Galaxy masses and their observational uncertainties., Comment: 23 pages, 12 figures, accepted for publication in MNRAS
- Published
- 2020
36. A Newly Documented Whole-Sky Circumpolar Constellation in Alaskan Gwich'in.
- Author
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Cannon, Chris and Holton, Gary
- Subjects
- *
ETHNOASTRONOMY , *URSA Major , *ASTRONOMICAL observations , *ASTERISMS (Astronomy) - Abstract
Traditional approaches to the documentation of indigenous astronomical knowledge often assume a one-to-one or near one-to-one correspondence between indigenous and classical constellation terms. Only a single constellation, equated with the Big Dipper, is robustly attested across the Northern Dene languages. Here we provide evidence from Gwich'in (Dene) that shows that the equation of this single Gwich'in constellation with the classical constellation is only partial. The Gwich'in constellation yahdii is actually a whole-sky constellation that maps nearly the entire sky. The Big Dipper is the tail of yahdii, and the remaining stars in the constellation are identified by other Gwich'in body-part terms, forming a unified functional conceptualization of the sky. Our work demonstrates how observational and cultural biases can prejudice the description of cultural astronomy. Dene astronomy is much richer than has been previously claimed and provides the first well-documented indigenous example of a whole-sky constellation. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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37. News Notes.
- Subjects
- *
ASTRONOMY , *ASTRONOMY education , *SUPERNOVAE , *URSA Major , *GALAXIES , *MARTIAN craters - Abstract
The article offers news briefs related to astronomy as April 2014. Undergraduate astronomy students from the University College London discovered a supernova in the M82 galaxy at Ursa Major on January 21, 2014. The Mars Reconnaissance Orbiter revealed on November 19, 2013 images of a new crater in Mars. A new galaxy was found by the Hubble and the Spitzer Space Telescopes near the Abell 2744 galaxy cluster.
- Published
- 2014
38. Neutron-capture elements in dwarf galaxies III. A homogenized analysis of 13 dwarf spheroidal and ultra-faint galaxies
- Author
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Michael Hanke, Camilla Juul Hansen, Á. Skúladóttir, Almudena Arcones, Eva K. Grebel, and Moritz Reichert
- Subjects
MILKY-WAY SATELLITE ,Ursa Major ,Stellar mass ,dwarf [galaxies] ,Metallicity ,fundamental parameters [stars] ,FOS: Physical sciences ,Ursa Minor ,CHEMICAL EVOLUTION ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,LTE LINE FORMATION ,CORE-COLLAPSE SUPERNOVAE ,0103 physical sciences ,abundances [galaxies] ,Astrophysics::Solar and Stellar Astrophysics ,GIANT BRANCH STARS ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,evolution [galaxies] ,Dwarf galaxy ,Physics ,EXTREMELY METAL-POOR ,010308 nuclear & particles physics ,R-PROCESS ,Astronomy and Astrophysics ,BOOTES ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,abundances [stars] ,Supernova ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,TRANSITION-PROBABILITIES ,S-PROCESS ,catalogs ,MULTIELEMENT ABUNDANCE MEASUREMENTS - Abstract
Context. We present a large homogeneous set of stellar parameters and abundances across a broad range of metallicities, involving 13 classical dwarf spheroidal (dSph) and ultra-faint dSph (UFD) galaxies. In total, this study includes 380 stars in Fornax, Sagittarius, Sculptor, Sextans, Carina, Ursa Minor, Draco, Reticulum II, Bootes I, Ursa Major II, Leo I, Segue I, and Triangulum II. This sample represents the largest, homogeneous, high-resolution study of dSph galaxies to date. Aims. With our homogeneously derived catalog, we are able to search for similar and deviating trends across different galaxies. We investigate the mass dependence of the individual systems on the production of α-elements, but also try to shed light on the long-standing puzzle of the dominant production site of r-process elements. Methods. We used data from the Keck observatory archive and the ESO reduced archive to reanalyze stars from these 13 classical dSph and UFD galaxies. We automatized the step of obtaining stellar parameters, but ran a full spectrum synthesis (1D, local thermal equilibrium) to derive all abundances except for iron to which we applied nonlocal thermodynamic equilibrium corrections where possible. Results. The homogenized set of abundances yielded the unique possibility of deriving a relation between the onset of type Ia supernovae and the stellar mass of the galaxy. Furthermore, we derived a formula to estimate the evolution of α-elements. This reveals a universal relation of these systems across a large range in mass. Finally, we show that between stellar masses of 2.1 × 107 M⊙ and 2.9 × 105 M⊙, there is no dependence of the production of heavy r-process elements on the stellar mass of the galaxy. Conclusions. Placing all abundances consistently on the same scale is crucial to answering questions about the chemical history of galaxies. By homogeneously analyzing Ba and Eu in the 13 systems, we have traced the onset of the s-process and found it to increase with metallicity as a function of the galaxy’s stellar mass. Moreover, the r-process material correlates with the α-elements indicating some coproduction of these, which in turn would point toward rare core-collapse supernovae rather than binary neutron star mergers as a host for the r-process at low [Fe/H] in the investigated dSph systems.
- Published
- 2020
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- View/download PDF
39. Dark Matter Density Profiles in Dwarf Galaxies: Linking Jeans Modeling Systematics and Observation
- Author
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Laura J. Chang and Lina Necib
- Subjects
Physics ,Ursa Major ,Annihilation ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Milky Way ,Dark matter ,FOS: Physical sciences ,Astronomy and Astrophysics ,Ursa Minor ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Stars ,High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Galaxy formation and evolution ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Galaxy Astrophysics ,Dwarf galaxy ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
The distribution of dark matter in dwarf galaxies can have important implications on our understanding of galaxy formation as well as the particle physics properties of dark matter. However, accurately characterizing the dark matter content of dwarf galaxies is challenging due to limited data and complex dynamics that are difficult to accurately model. In this paper, we apply spherical Jeans modeling to simulated stellar kinematic data of spherical, isotropic dwarf galaxies with the goal of identifying the future observational directions that can improve the accuracy of the inferred dark matter distributions in the Milky Way dwarf galaxies. We explore how the dark matter inference is affected by the location and number of observed stars as well as the line-of-sight velocity measurement errors. We use mock observation to demonstrate the difficulty in constraining the inner core/cusp of the dark matter distribution with datasets of fewer than 10,000 stars. We also demonstrate the need for additional measurements to make robust estimates of the expected dark matter annihilation signal strength. For the purpose of deriving robust indirect detection constraints, we identify Ursa Major II, Ursa Minor, and Draco as the systems that would most benefit from additional stars being observed., 27+16 pages, 12+17 figures
- Published
- 2020
40. HUBBLE DEEP FIELD The picture worth a trillion stars.
- Author
-
James, C. Renée
- Subjects
- *
HUBBLE deep field , *OUTER space , *ASTRONOMICAL research , *URSA Major - Abstract
The article focuses on the Hubble Deep Field (HDF), an image of a small region in the constellation Ursa Major, constructed from observations by the Hubble Space Telescope (HST) and its contributions to astronomical research. Topics discussed include views of Robert Williams, former director of the Space Telescope Science Institute (STScI), significance of multiwavelength exposures IN learning distance, and incarnation of the HDF in the Ultraviolet Coverage of Hubble Ultra Deep Field project.
- Published
- 2015
41. The Hercules-Lyra association revisited.
- Author
-
Eisenbeiss, T., Ammler-von Eiff, M., Roell, T., Mugrauer, M., Adam, Ch., Neuhäuser, R., Schmidt, T. O. B., and Bedalov, A.
- Subjects
- *
STELLAR chromospheres , *BINARY systems (Astronomy) , *URSA Major , *PLEIADES , *KINEMATICS - Abstract
Context. The Hercules-Lyra association, a purported nearby young moving group, contains a few tens of zero age main sequence stars of spectral types F to M. The existence and the properties of the Her-Lyr association are controversial and have been discussed in the literature. Aims. The present work reassesses the properties and the member list of the Her-Lyr association based on kinematics and age indicators. Many objects form multiple systems or have low-mass companions and so we need to properly account for multiplicity. Methods. We use our own new imaging observations and archival data to identify multiple systems. The colors and magnitudes of kinematic candidates are compared to isochrones. We derive further information on the age based on Li depletion, rotation, and coronal and chromospheric activity. A set of canonical members is identified to infer mean properties. Membership criteria are derived from the mean properties and used to discard non-members. Results. The candidates selected from the literature belong to 35 stellar systems, 42.9% of which are multiple. Four multiple systems (V538 Aur, DX Leo, V382 Ser, and HH Leo) are confirmed in this work by common proper motion. An orbital solution is presented for the binary system which forms a hierarchical triple with HHLeo. Indeed, a group of candidates displays signatures of youth. Seven canonical members are identified The distribution of Li equivalent widths of canonical Her-Lyr members is spread widely and is similar to that of the Pleiades and the UMa group. Gyrochronology gives an age of 257 ± 46 Myr which is roughly in between the ages of the Pleiades and the Ursa Major group. The measures of chromospheric and coronal activity support the young age. Four membership criteria are presented based on kinematics, lithium equivalent width, chromospheric activity, and gyrochronological age. In total, eleven stars are identified as certain members including co-moving objects plus additional 23 possible members while 14 candidates are doubtful or can be rejected. A comparison to the mass function, however, indicates the presence of a large number of additional low-mass members, which remain unidentified. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
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42. THE DISTRIBUTION OF ALPHA ELEMENTS IN ULTRA-FAINT DWARF GALAXIES.
- Author
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VARGAS, LUIS C., GEHA, MARLA, KIRBY, EVAN N., and SIMON, JOSHUA D.
- Subjects
- *
DWARF galaxies , *RED giants , *STARS , *URSA Major ,UNIVERSE - Abstract
The Milky Way ultra-faint dwarf (UFD) galaxies contain some of the oldest, most metal-poor stars in the universe. We present [Mg/Fe], [Si/Fe], [Ca/Fe], [Ti/Fe], and mean [α/Fe] abundance ratios for 61 individual red giant branch stars across eight UFDs. This is the largest sample of alpha abundances published to date in galaxies with absolute magnitudes MV > -8, including the first measurements for Segue 1, Canes Venatici II, Ursa Major I, and Leo T. Abundances were determined via medium-resolution Keck/DEIMOS spectroscopy and spectral synthesis. The sample spans the metallicity range -3.4 < [Fe/H] < -1.1. With the possible exception of Segue 1 and Ursa Major II, the individual UFDs show on average lower [α/Fe] at higher metallicities, consistent with enrichment from Type Ia supernovae. Thus, even the faintest galaxies have undergone at least a limited level of chemical self-enrichment. Together with recent photometric studies, this suggests that star formation in the UFDs was not a single burst, but instead lasted at least as much as the minimum time delay of the onset of Type Ia supernovae (~100 Myr) and less than~2 Gyr.We further show that the combined population of UFDs has an [α/Fe] abundance pattern that is inconsistent with a flat, Galactic halo-like alpha abundance trend, and is also qualitatively different from that of the more luminous CVn I dSph, which does show a hint of a plateau at very low [Fe/H]. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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- View/download PDF
43. VARIABLE STARS IN THE ULTRA-FAINT DWARF SPHEROIDAL GALAXY URSA MAJOR I.
- Author
-
GAROFALO, ALESSIA, CUSANO, FELICE, CLEMENTINI, GISELLA, RIPEPI, VINCENZO, DALL'ORA, MASSIMO, MORETTI, MARIA IDA, COPPOLA, GIUSEPPINA, MUSELLA, ILARIA, and MARCONI, MARCELLA
- Subjects
- *
VARIABLE stars , *ELLIPTICAL galaxies , *STAR observations , *STELLAR oscillations , *DWARF galaxies , *URSA Major , *MILKY Way - Abstract
We have performed the first study of the variable star population of Ursa Major I (UMa I), an ultra-faint dwarf satellite recently discovered around the Milky Way (MW) by the Sloan Digital Sky Survey. Combining time series observations in the B and V bands from four different telescopes, we have identified seven RR Lyrae stars in UMa I, of which five are fundamental-mode (RRab) and two are first-overtone pulsators (RRc). Our V, B-V color-magnitude diagram of UMa I reaches V ~23 mag (at a signal-to-noise ratio of~6) and shows features typical of a single old stellar population. The mean pulsation period of the RRab stars (Pab) = 0.628, σ = 0.071 days (or (Pab) = 0.599, σ = 0.032 days, if V4, the longest period and brightest variable, is discarded) and the position on the period-amplitude diagram suggest an Oosterhoff-intermediate classification for the galaxy. The RR Lyrae stars trace the galaxy horizontal branch (HB) at an average apparent magnitude of (V (RR)) = 20.43±0.02 mag (average on six stars and discarding V4), giving in turn a distance modulus for UMa I of (m-M)0 = 19.94 ± 0.13 mag, distance d=97.3+6.0 -5.7 kpc, in the scale where the distance modulus of the Large Magellanic Cloud is 18.5±0.1mag. Isodensity contours of UMa I red giants and HB stars (including the RR Lyrae stars identified in this study) show that the galaxy has an S-shaped structure, which is likely caused by the tidal interaction with the MW. Photometric metallicities were derived for six of the UMa I RR Lyrae stars from the parameters of the Fourier decomposition of the V-band light curves, leading to an average metal abundance of [Fe/H]=-2.29 dex (σ = 0.06 dex, average on six stars) on the Carretta et al. metallicity scale. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
44. Distribution and evolution of galaxy groups in the Ursa Major supercluster.
- Author
-
Ribeiro, A. L. B., Lopes, P. A. A., and Krause, M. O.
- Subjects
- *
GALAXY formation , *SUPERCLUSTERS , *REDSHIFT , *GAUSSIAN processes , *URSA Major - Abstract
Context. We study an SDSS sample of galaxies within ~50 Mpc of the nominal center of the Ursa Major supercluster. Aims. Our aim is to study galaxy distribution around groups in the supercluster and the link between the distribution of relaxed and nonrelaxed galaxy systems with respect to the supercluster environment. Methods. Using the FoF algorithm, 40 galaxy groups were identified in this region. Velocity distributions for these groups were studied after applying a 3σ-clipping routine for outlier removal. We classified the systems according to the results of normality and substructure tests applied to member galaxies. Then, we studied the relative distribution of relaxed and nonrelaxed systems across the supercluster. Results. We find that 68% of galaxy groups are Gaussian and that all the non-Gaussian systems have substructures and probably correspond to multimodal systems in redshift space. We also find that the Gaussian systems inhabit the denser regions of the supercluster, with higher densities of both red and blue galaxies within 2.5 h-1 Mpc, and have smaller group-group pairwise separations. Conclusions. Our results suggest a spatial segregation of dynamical states, where relaxed systems may have formed and evolved earlier and faster around high-density peaks, while nonrelaxed systems may be growing slower on the peripheries of lower density peaks. In this picture, galaxy clustering seems to be prompting a continuous internal evolution in the supercluster, with several groups collapsing into the more evolved and contracted regions. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
45. A blind H i survey in the Ursa Major region★.
- Author
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Wolfinger, K., Kilborn, V. A., Koribalski, B. S., Minchin, R. F., Boyce, P. J., Disney, M. J., Lang, R. H., and Jordan, C. A.
- Subjects
- *
DENSITY of stars , *STELLAR mass , *COMPARATIVE studies , *DATA analysis , *SURVEYS , *URSA Major - Abstract
We have conducted the first blind H i survey covering 480 deg2 and a heliocentric velocity range from 300 to 1900 km s−1 to investigate the H i content of the nearby spiral-rich Ursa Major region and to look for previously uncatalogued gas-rich objects. Here we present the catalogue of H i sources. The H i data were obtained with the four-beam receiver mounted on the 76.2-m Lovell telescope [full width at half-maximum (FWHM) 12 arcmin] at the Jodrell Bank Observatory (UK) as part of the H i Jodrell All Sky Survey (HIJASS). We use the automated source finder duchamp and identify 166 H i sources in the data cubes with H i masses in the range of 107–1010.5 M⊙. Our Ursa Major H i catalogue includes 10 first-time detections in the 21-cm emission line.We identify optical counterparts for 165 H i sources (99 per cent). For 54 H i sources (∼33 per cent) we find numerous optical counterparts in the HIJASS beam, indicating a high density of galaxies and likely tidal interactions. Four of these H i systems are discussed in detail.We find only one H i source (1 per cent) without a visible optical counterpart out of the 166 H i detections. Green Bank Telescope (FWHM 9 arcmin) follow-up observations confirmed this H i source and its H i properties. The nature of this detection is discussed and compared to similar sources in other H i surveys. [ABSTRACT FROM PUBLISHER]
- Published
- 2013
- Full Text
- View/download PDF
46. Study of X-ray and γ-ray flare from Mkn-421 during February 2010 using Swift and Fermi observations
- Author
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Singh, K.K., Bhattacharyya, S., Bhatt, N., and Tickoo, A.K.
- Subjects
- *
X-ray astronomy , *TELESCOPES , *ASTRONOMICAL instruments , *GAMMA ray astronomy , *BL Lacertae objects , *ENERGY bands , *URSA Major - Abstract
Abstract: In this work, we report on the intense flaring activity from Mkn-421 in X-ray and γ-ray regimes simultaneously observed by Swift-XRT/BAT and Fermi-LAT satellite telescopes in February 2010. With the aim of understanding the underlying physics of the flaring state in Mkn-421, we have performed a detailed spectral analysis of Swift/XRT and Fermi/LAT observations of Mkn-421 during February 12–25, 2010 (MJD 55239–55252). Over this period, we study the daily light curves and spectral variability of the source in 1–10keV, 0.1–1GeV and 1–100GeV energy bands. We have performed the spectral analysis of Swift-XRT and Fermi/LAT observations to study the spectral evolution in the X-ray and gamma-ray energy domains respectively. We also compute the fractional variability amplitude in both the energy bands during the above period. We study trends between spectral parameters and physical insights provided by the parameter responsible for X-ray and γ-ray emission from the source. We search for energetic features phenomenologically linked to the single zone SSC model for blazar emission. We also produce the broad band SED with a leptonic single zone SSC model for the source. [Copyright &y& Elsevier]
- Published
- 2012
- Full Text
- View/download PDF
47. Apollo, Helios, and the Solstices in the Athenian, Delphian, and Delian Calendars.
- Author
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Bilić, Tomislav
- Subjects
- *
GREEK calendar , *APOLLO (Deity) , *HELIOS (Greek deity) , *WINTER solstice -- Religious aspects , *SUMMER solstice , *GREEK mythology , *URSA Major , *HISTORY ,GREEK religion - Abstract
The mythical narrative of Apollo's northern voyage and the place of his festivals in several Greek calendars, reflected also in local ritual practice, seems to reflect certain elements in his nature best explained through his association with the sun, more precisely, the annual solar movement. The association was noted long ago, but a selective analysis will show that both the narrative and the ritual reflect the model of annual solar motion expressed in terms of a suspended reference, a mythical metaphor, a linear narrative defined both by the very nature of language and the celestial phenomenon it is describing. The analysis of various Greek calendars supports the notion of the solstices as the most important defining moments in the annual solar motion, and their connection with Apollo reflects precisely this fact. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
48. The chemical composition of nearby young associations: s-process element abundances in AB Doradus, Carina-Near and Ursa Major.
- Author
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D'Orazi, V., Biazzo, K., Desidera, S., Covino, E., Andrievsky, S. M., and Gratton, R. G.
- Subjects
- *
STAR clusters , *STELLAR chromospheres , *HIGH resolution spectroscopy , *BARIUM compounds , *MATHEMATICAL models , *URSA Major - Abstract
ABSTRACT Recently, several studies have shown that young, open clusters are characterized by a considerable overabundance in their barium content. In particular, D'Orazi et al. reported that in some younger clusters [Ba/Fe] can reach values as high as ∼0.6 dex. The work also identified the presence of an anticorrelation between [Ba/Fe] and cluster age. For clusters in the age range ∼4.5 Gyr -500 Myr, this is best explained by assuming a higher contribution from low-mass asymptotic giant branch stars to the Galactic chemical enrichment. The purpose of this work is to investigate the ubiquity of the barium overabundance in young stellar clusters. We analysed high-resolution spectroscopic data, focusing on the s-process elemental abundance for three nearby young associations, i.e. AB Doradus, Carina-Near and Ursa Major. The clusters have been chosen such that their age spread would complement the D'Orazi et al. study. We find that while the s-process elements Y, Zr, La and Ce exhibit solar ratios in all three associations, Ba is overabundant by ∼0.2 dex. Current theoretical models cannot reproduce this abundance pattern; thus, we investigate whether this unusually large Ba content might be related to chromospheric effects. Although no correlation between [Ba/Fe] and several activity indicators seems to be present, we conclude that different effects could be at work which may (directly or indirectly) be related to the presence of hot stellar chromospheres. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
49. The chemical composition of nearby young associations: s-process element abundances in AB Doradus, Carina-Near and Ursa Major.
- Author
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D’Orazi, V., Biazzo, K., Desidera, S., Covino, E., Andrievsky, S. M., and Gratton, R. G.
- Subjects
URSA Major ,OPEN clusters of stars ,LOW mass stars ,SOLAR chromosphere ,GEOCHEMISTRY - Abstract
Recently, several studies have shown that young, open clusters are characterized by a considerable overabundance in their barium content. In particular, D’Orazi et al. reported that in some younger clusters [Ba/Fe] can reach values as high as ∼0.6 dex. The work also identified the presence of an anticorrelation between [Ba/Fe] and cluster age. For clusters in the age range ∼4.5 Gyr-500 Myr, this is best explained by assuming a higher contribution from low-mass asymptotic giant branch stars to the Galactic chemical enrichment.The purpose of this work is to investigate the ubiquity of the barium overabundance in young stellar clusters. We analysed high-resolution spectroscopic data, focusing on the s-process elemental abundance for three nearby young associations, i.e. AB Doradus, Carina-Near and Ursa Major. The clusters have been chosen such that their age spread would complement the D’Orazi et al. study.We find that while the s-process elements Y, Zr, La and Ce exhibit solar ratios in all three associations, Ba is overabundant by ∼0.2 dex. Current theoretical models cannot reproduce this abundance pattern; thus, we investigate whether this unusually large Ba content might be related to chromospheric effects. Although no correlation between [Ba/Fe] and several activity indicators seems to be present, we conclude that different effects could be at work which may (directly or indirectly) be related to the presence of hot stellar chromospheres. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
50. A spectroscopic study of DD UMa: Ursa Major group member and candidate for BRITE
- Author
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Elmaslı, A., Fossati, L., Folsom, C.P., Albayrak, B., and Izumiura, H.
- Subjects
- *
ASTRONOMICAL spectroscopy , *SUPERCLUSTERS , *MILKY Way , *CONSTELLATIONS , *SPECTROGRAPHS , *SPECTRUM analysis , *URSA Major - Abstract
Abstract: The Ursa Major group is a nearby stellar supercluster which, while not gravitationally bound, is defined by co-moving members. DD UMa is a δ Scuti star whose membership in the Ursa Major group is unclear. The objective of this study is to confirm the membership of DD UMa in the Ursa Major group, as well as perform a detailed spectral analysis of the star. Since DD UMa is a low-amplitude δ Scuti star, we performed a frequency analysis. We determined fundamental parameters, chemical abundances, and derive a mass and age for the star. For this study we observed DD UMa at the Okayama Astrophysical Observatory with the high-resolution spectrograph HIDES, between the 27th of February and the 4th March, 2009. Additional observations were extracted from the ELODIE archive in order to expand our abundance analysis. Group membership of DD UMa was assessed by examining the velocity of the star in Galactic coordinates. Pulsational frequencies were determined by examining line profile variability in the HIDES spectra. Stellar fundamental parameters and chemical abundances were derived by fitting synthetic spectra to both the HIDES and ELODIE observations. DD UMa is found to be a member of the extended stream of the Ursa Major group, based on the space motion of the star. This is supported by the chemical abundances of the star being consistent with those of Ursa Major group members. The star is found to be chemically solar, with T eff =7450±150K and logg =3.98±0.2. We found pulsational frequencies of 9.4 and 15.0c/d. While these frequencies are insufficient to perform an asteroseismic study, DD UMa is a good bright star candidate for future study by the BRITE-constellation. [Copyright &y& Elsevier]
- Published
- 2012
- Full Text
- View/download PDF
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