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Start Over Author "Silvotti, R." Database Directory of Open Access Journals
11 results on '"Silvotti, R."'

1. Asteroseismology of Pulsating sdB Stars Observed at Catania Astrophysical Observatory

Author

Bonanno A., Frasca A., Lanza A. F., Ventura R., Mignemi B., and Silvotti R.

Subjects
Astronomy, QB1-991
Abstract

We present analysis of the data collected during three years of photometric campaigns at the 91 cm Cassegrain telescope of the Catania Astrophysical Observatory to observe the pulsating subdwarf B star PG 1336-018. For this eclipsing binary system, we obtained a precise determination of the orbital period which turns out to be P = 0.10101599±0.00000002 days. Time-series photometry reveals pulsation periods near 174 and 184 seconds. We also discuss a preliminary analysis of the data obtained in 2002 for the pulsating subdwarf PG 1325+101.

Published
2003
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2. V351 Ori as a Target for the Wet

Author

Ripepi V., Marconi M., and Silvotti R.

Subjects
stars, variable - stars, individual, V351 Ori, Astronomy, QB1-991
Abstract

We present time series observations of the Herbig Ae star V351 Ori. This star presents light variations on short time scale (a few hours), typical of the δ Scuti pulsation. The new data are briefly described and the possibility to observe V351 Ori with the WET is discussed.

Published
2003
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3. PG 1605+072 in Wet XCov22: Support for the Multi Site Spectroscopic Telescope

Author

Schuh S. L., Heber U., Dreizler S., O’Toole S., Jeffery C. S., Falter S., Woolf V.M., Riddle R. L., Handler G., Hürkal Ö., Pakštiene E., Klumpe E.W., Laurance T., Vuckovic M., Zoła S., Kawaler S. D., Kanaan A., Monteiro H., Giovannini O., Kepler S. O., Mukadam A., Provencal J.L., Nitta A., Shipman H., Mullally F., Grauer A., Wood M.A., Bradley P.A., Kilic M., Sekiguchi K., Crowe R., Sullivan D. J., Rosen R., Clemens C., Xiaojun J., Janulis R., O’Donoghue D., Ogloza W., Baran A., Silvotti R., Marinoni S., Vauclair G., Dolez N., Chevreton M., Deetjen J. L., Nagel T., Pérez J.M. González, Solheim J.-E., Østensen R., Ulla A., Burleigh M., Good S., Metcalfe T. S., Costa A. F.M. da, Costa J. E. S., O’Brien M.S., Kim S.-L., Lee H., Sergeev A., Akan C., Cakirli Ö., Paparo M., and Viraghalmy G.

Subjects
stars, interiors - stars, individual, PG 1605+072, Astronomy, QB1-991
Abstract

The Multi-site spectroscopic telescope is a virtual instrument and the name of a collaboration that opens up a new observational window by combining continuous observations of spectroscopic variations and simultaneous photometric monitoring. This constitutes an enormous observational effort, but in return promises to finally provide access to a mode identification for and an asteroseismological analysis of the pulsating sdB star PG 1605+072. Multi-Site Spectroscopic Telescope observations for this object have been secured during a large coordinated campaign in May and June of the year 2002. The frequency resolution and coverage of the photometric time series has been noticeably enhanced by a significant contribution from the Whole Earth Telescope, which was used to observe PG 1605+072 as an alternate target during the WET XCov22 campaign, also conducted in May 2002. This paper briefly outlines the motivation for the MSST project and tries to give a first assessment of the overall quality of the data obtained, with a focus on the Whole Earth Telescope observations.

Published
2003
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4. Constraining the Evolution of ZZ Ceti

Author

Mukadam A. S., Kepler S. O., Winget D. E., Nather R. E., Kilic M., Mullally F., Hippel T. von, Kleinman S. J., Nitta A., Guzik J. A., Bradley P. A., Matthews J., Sekiguchi K., Sullivan D. J., Shobbrook R. R., Birch P., Jiang X. J., Xu D. W., Joshi S., Ashoka B.N., Ibbetson P., Leibowitz E., Ofek E. O., Meištas E. G., Janulis R., Ališauskas D., Kalytis R., Handler G., Kilkenny D., O’Donoghue D., Kurtz D. W., Müller M., Moskalik P., Ogłoza W., Zoła S., Krzesiński J., Johannessen F., Gonzalez-Perez J. M., Solheim J-E., Silvotti R., Bernabei S., Vauclair G., Dolez N., Fu J. N., Chevreton M., Manteiga M., Súarez O., Ulla A., Cunha M. S., Metcalfe T. S., Kanaan A., Fraga L., Costa A. F. M., Giovannini O., Fontaine G., Bergeron P., O’Brien M. S., Sanwal D., Wood M. A., Ahrens T. J., Silvestri N., Klumpe E. W., Kawaler S. D., Riddle R., Reed M. D., and Watson T. K.

Subjects
stars, white dwarfs, individual, ZZ Cet, R548 - stars, pulsations, evolution, Astronomy, QB1-991
Abstract

We report our analysis of the stability of pulsation periods in the DAV star (pulsating hydrogen atmosphere white dwarf) ZZ Ceti, also called R548. Based on observations that span 31 years, we conclude that the period 213.132605 s observed in ZZ Ceti drifts at a rate dP/dt≤(5.5±1.9)×10−15 s/s, after correcting for proper motion. Our results are consistent with previous Ṗ values for this mode and an improvement over them due to the larger time-base. The characteristic stability timescale implied for the pulsation period is |P/ Ṗ|≥1.2 Gyr, comparable to the theoretical cooling timescale for the star. Our current stability limit for the period 213.132605 s is only slightly less than the present measurement for G117-B15A for the period 215.2 s, another DAV, establishing this mode in ZZ Ceti as the second most stable optical clock known, more stable than atomic clocks and most pulsars.

Published
2003
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7. Preliminary Results from XCOV 17: PG 1336-018

Author

Reed M. D., Kilkenny D., Kawaler S. D., Mukadam A., Kleinman S. J., Nitta-Kleinman A., Provencal J. L., Watson T., Sullivan D., Sullivan T., Shobbrook B., Jiang X. J., Ashoka B. N., Seetha S., Leibowitz E., Ibbetson P., Mendelson H., Meistas E. G., Kalytis R., Alisauskas D., O'Donoghue D., Martinez P., Wyk F. van, Stobie R., Marang F., Zola S., Krzesinski J., Ogloza W., Mosaklik P., Silvotti R., Piccioni A., Vauclair G., Dolez N., Rene-Fremy J., Chevreton M., Ulla A., Dreizler S., Schuh S., Deetjen J., Solheim J. E., Perez J., Suarez O., Manteiga M., Burleigh M., Barstow M., Kepler S. O., Kanaan A., Giovannini O., Metcalfe T., and Ostensen R.

Subjects
Astronomy, QB1-991
Published
2000
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9. The Intermediate Polar PQ Gem - Status of WET Observations of 1996

Author

Marar Τ. Μ. K., Seetha S., Ashoka B. N., Kasturirangan K., Mahra H. S., Bhattacharyya J. C., Leibowitz Ε. M., Hemar S., Mendelson H., Ibbetson P. A., O’Donoghue D., Buckley D. A. H., Βreger M., Handler G., Sperl M., Serkowitsch E., Reegen P., Moskalik P., Zola S., Pajdosz G., Krzesinski J., Silvotti R., Vauclair G., Dolez N., Solheim J. E., Pfeiffer B., Kepler S. O., Kanaan A., Provencal J., Kawaler S. D., O'Brien M. S., Nather R. E., Winget D. E., Kleinman S., Nitta A., Bradley P. A., Guzik J. A., Clemens C., Sullivan D. J., and Jiang X.

Subjects
Astronomy, QB1-991
Published
1998
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