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В статье приводится обзор истории изучения внешних оболочек Солнца по зарубежным источникам. Дается периодизация процесса изучения Солнца и результаты, с которыми научное сообщество приступило к изучению Солнца с помощью космических аппаратов.

Measuring the concentration of methane in the atmosphere is demonstrated to be very important, since an increase in methane content enhances the greenhouse effect. It is shown that the error in assessing the concentration of CH4 depends on many factors, including the reliability of the parameters of the spectral absorption lines of gases, the accuracy of determining the concentration, the measurement error, etc. The spectroscopic information necessary to detect sources of high methane concentration in the atmosphere using CO and He – Ne lasers is analysed.

The near infrared transmission spectra of nanoporous SiO2/Al2O3 xerogel have been recorded for the first time in the process of filling of nanopores with ammonia and acetone molecules. It has been found that the physical adsorption of these gases results in a reversible increase in the translucence of xerogel samples at the frequencies of vibrational bands of surface OH groups.

The absorption spectrum of water vapor in “natural” isotopic abundance has been recorded at room temperature by high sensitivity Continuous Wave Cavity Ring Down Spectroscopy (CW-CRDS) between 7911 and 8337 cm −1 . The investigated region covers most of the 1.25 µm transparency window of importance for atmospheric applications. The recordings were performed with sensitivity on the order of α min ~2×10 –11 cm −1 , more than two orders of magnitude better than previous investigations by Fourier Transform Spectroscopy (FTS). Measured line intensities cover a range of seven orders of magnitude (3×10 –30 –2×10 –23 cm/molecule at room temperature). The experimental line list provided as Supplementary Material includes more than 5000 transitions. As a result of the achieved sensitivity, more than 1150 lines of the experimental list were identified as being due to ammonia present as an impurity at the 5 ppm concentration level in the water sample. Although incomplete, the obtained ammonia line list seems to be the first one in the region. More than 3193 water lines were assigned to 3560 transitions of five water isotopologues (H 2 16 O, H 2 18 O, H 2 17 O, HD 16 O and HD 18 O). The assignments were performed using known experimental energy levels and calculated spectra based on variational calculations by Schwenke and Partridge. The obtained results are compared to the most relevant previous studies by Fourier Transform Spectroscopy in the region and to the exhaustive review of rovibrational line positions and levels performed recently by an IUPAC sponsored task group. Two-hundred and sixty-six levels are newly determined and 46 are corrected by more than 0.015 cm −1 compared to those recommended by the water IUPAC task group. The overall agreement between variational and measured intensities is satisfactory. A complete empirical list of 4473 transitions incorporating all the experimental information at disposal was constructed for water in the studied region. The intensity cut-off was fixed to 1×10 –29 cm/molecule at 296 K. A detailed comparison with the line list as provided by the HITRAN database illustrates the advantages of the new list.

The room temperature spectrum of carbon monoxide in natural isotopic abundance is recorded by Cavity Ring Down Spectroscopy between 8094 and 8317 cm −1 . The investigated range covers the low frequency region of the third overtone band centered at 8414 cm −1 . The achieved sensitivity of the recordings corresponds to a noise equivalent absorption, α min ~ 5×10 –12 cm −1 . 94 transitions are measured with intensity ranging between 3×10 –27 and 1×10 –30 cm/molecule. They include the first observation of (i) high J lines of the P branch of the 4-0 band of 12 C 16 O, (ii) the 4-0 band of 13 C 16 O and 12 C 18 O present in natural abundance in the sample (35 and 38 transitions, respectively), (iii) a few lines of the 4-0 band of 12 C 17 O and of the 5-1 hot band of 12 C 16 O. The spectroscopic parameters of the v =4 upper level of 13 C 16 O and 12 C 18 O are obtained from a fit of the measured line positions. The line positions reported with an accuracy of 5×10 −4 cm −1 and the derived line intensities are used for comparison to various theoretical line lists of carbon monoxide available in the literature. The agreement between the obtained experimental data and the most recent theoretical line lists available in the literature is discussed.

An application of one-dimensional velocity approach to calculation of speed-dependent spectral line profiles was considered. It was shown that a mean deviation of the line profile obtained within this approach from the line profile derived with integrating over three projections of an absorbing molecule's velocity does not exceed 1.1% at mass ratios of perturbing and absorbing molecules ≤9. Analytical approximate expressions for speed-dependent line profiles, including spectral line narrowing and mixing, were obtained for one- and three-dimensional velocity approaches.

Systematic errors inherent in the Voigt line profile are analyzed. Molecular spectrum processing with the Voigt profile is shown to underestimate line intensities by 1–4%, with the errors in line positions being 0.0005 cm−1 and the decrease in pressure broadening coefficients varying from 5% to 55%.

Пособие восполняет существенный недостаток в учебной литературе по теоретической астрофизике. В этом пособии рассматриваются вопросы теории образования спектральных линий в спектрах звезд, излагаются механизмы уширения линий, даются методы решения уравнения переноса излучения с учетом поглощения в линиях. Приведены главные результаты использования спектральных линий для диагностики звездных атмосфер (определение температур, давлений, химического состава, вращения). Приведены сведения о звездных ветрах, микро и макро турбуленции. Теоретическая астрофизика

Пособие восполняет существенный недостаток в учебной литературе по теоретической астрофизике. В этом пособии рассматриваются вопросы теории образования спектральных линий в спектрах звезд, излагаются механизмы уширения линий, даются методы решения уравнения переноса излучения с учетом поглощения в линиях. Приведены главные результаты использования спектральных линий для диагностики звездных атмосфер (определение температур, давлений, химического состава, вращения). Приведены сведения о звездных ветрах, микро и макро турбуленции. Теоретическая астрофизика

Пособие восполняет существенный недостаток в учебной литературе по теоретической астрофизике. В этом пособии рассматриваются вопросы теории образования спектральных линий в спектрах звезд, излагаются механизмы уширения линий, даются методы решения уравнения переноса излучения с учетом поглощения в линиях. Приведены главные результаты использования спектральных линий для диагностики звездных атмосфер (определение температур, давлений, химического состава, вращения). Приведены сведения о звездных ветрах, микро и макро турбуленции. Теоретическая астрофизика