Hot subdwarfs are hots stars with masses somewhat less than that of the Sun. ... They are known as sdB stars because their spectra are dominated by hydrogen lines. ... Normally, a red giant will switch on core helium burning without losingthe layers of hydrogen around the helium core. sdOB stars are related to sdB stars, possibly being the sdB stars which have completed core helium burning and are evolving to become white dwarfs. ... Such stars are known as PG1159 stars and DO white dwarfs. ...

... Роман Евгеньевич Ильинский email : ilinsky_r@mail.ru . ... Ильинский Р. Е., Ровенская Т. С. Дифференциалы луча в оптической системе // Вестник МГТУ. ... 1998.- ... Roman Ilinsky , Gradient-index meniscus lens free of spherical aberration, Journal of Optics A: Pure and Applied Optics, volume2, number 5, pages 449-451, year 2000 . ... Ильинский Р. Е. Определение реальных габаритов пучков в градиентных оптических системах // Прикладная оптика -2000: Тез. докл. ... 2000.- ... ROMAN ILINSKY . ...

... Flux density at 1 GHz (/Jy): 18? ... Radio: Flat spectrum core within steep spectrum shell. X-ray: Central core, with non-thermal spectrum. ... Helfand & Becker 1987, ApJ, 314, 203. VLA at 1.4 and 5 GHz, and Einstein observations. ADS . ... Parkes 64-m OH observations. ... X-ray detection. ... VLA at 333 MHz (43''?24''). ... BeppoSAX observations. ... VLA at 1.4 GHz (8".6?11".3). ... ATCA and VLA at 1.4 GHz (1".2?2".5: S=8.3?0.7 Jy), 5 GHz (1".6?2".5) and 8.3 GHz (0".8?1".5). ...

... 50 Greatest Mysteries . ... Star Atlas . ... Supernova showered Earth with radioactive debris . ... stars . ... Cosmic Adventures . ... Closest type Ia supernova in decades solves a cosmic mystery . ... Confirming a carbon-oxygen white dwarf . ... The spectra gave us the carbon and oxygen, so we knew we had the first direct evidence that a type Ia supernova does indeed start with a carbon-oxygen white dwarf." ... Only registered members of Astronomy.com are allowed to comment on this article. ...

. These are all basically the same things: waves of entwined electricity and magnetism flying through space: the only thing that’s different is the wavelength. You also get waves longer than radio and shorter than Gamma Rays - but these are very rare, and as far as we know useless (at present). Our eyes are only sensitive to visible light. Previous slide . Next slide . Back to first slide . View graphic version .

Next: Imaging Polarimetry with NICMOS Up: NICMOS Data Calibration and Previous: The Photometric Performance of . ... NICMOSlook and Calnic C . ... Extracting spectra from a large number of NICMOS grism images requires a convenient interactive tool which allows a user to manipulate direct/grism image pairs. ... NICMOSlook and Calnic-C are two programs that were designed to take advantage of the fact that the NICMOS grism mode typically consists of taking both a direct and a grism image. ...

... Before the modern era of technological astronomy, to know anything about the Universe beyond our planet we relied on light. ... Historically the two rival ideas were that light was either a stream of tiny bullet-like particles or a wave wobbling its way through space. ... The light we see (visible light which is not the tautology it sounds) is only part of the electromagnetic spectrum, a great sweep of radiations which also includes radio, infra-red, ultra-violet, x-rays and gamma rays. ...

... ASpect is spectrum analysis package being developed at ST ScI. We discuss the implementation of a GUI using the IRAF Object Manager, the ASpect task design, and the mechanics of performing a fit to a spectral feature with ASpect. ASpect is a spectrum and line analysis package being developed at ST ScI. ... For example, the fit library ``knows'' about the component and spectrum objects but a given spectrum or component object knows nothing of fitting. ...

... Telescopes ћ Binoculars ћ Microscopes . Meade Ultra-High Transmission coatings (UHTC ) Group . ... Meade Standard Coatings: The optical surfaces of all Meade telescopes include high-grade optical coatings fully consistent in quality with the precision of the optical surfaces themselves. ... These specialized, and extremely advantageous, coatings are offered here as the Meade Ultra-High Transmission Coatings (UHTC) group, a coatings group available optionally on many Meade telescope models. ...

Classroom Activity: Making a Rainbow . ... When white light from the Sun or a light bulb passes through a prism, the light splits into its component wavelengths. ... Red, blue, green colored filters - if possible, cut 1x4-inch pieces of the filters for each student . ... Many students have the misconception that filters somehow dye the light a certain color. ... Younger students can draw the rainbow and make up a mnemonic for remembering the order of the colors (such as, ROY G. BIV). ...

... We thank the Swift team for their rapid scheduling of this observation. ... 2455705.20851 V 14.15 0.03 2455707.83079 V 14.10 0.03 2455710.84028 V 13.53 0.02 2455713.64631 V 13.66 0.02 2455714.65479 V 14.11 0.03 2455714.71823 V 14.12 0.02 2455714.78596 V 14.20 0.02 2455717.39593 V 14.37 0.03 2455726.62861 V 14.83 0.04 2455727.16343 V 14.57 0.04 2455730.50586 V 14.57 0.03 2455730.57329 V 14.56 0.03 2455730.70360 V 14.66 0.04 2455738.32865 V 14.00 0.02 2455742.86146 V 14.21 ...