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| | IK Pegasi(HR 8210) - Team 310 - Bulgaria |
 | | HR 8210 is a binary star with a normal star for a main component ( IK Pegasi A) and a hot white dwarf for a secondary component ( IK Pegasi B). | | | Also the merging of two white dwarfs assumes that the mass of the two merging dwarfs is lower than average, assuming a mass in their previous stages is even lower than the mass of the present A star. | | | They are called "Dwarf Cepheids" because they seem to be different from RR Lyrae stars because of their higher metallicity and different period-luminosity relation. |
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http://eso.org/outreach/eduoff/edu-prog/catchastar/casreports-2004/rep-310
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| | Discovery of Low-Luminosity Carbon Stars in the Fornax Dwarf Spheroidal Galaxy with MOS at CFHT |
| | C-Star Population in the Fornax Dwarf Spheroidal Galaxy | | | Near-infrared JHK photometry of nearly all the C-stars identified in the Fornax dwarf, mainly carried out by us with IRAC2 at the ESO 2.2-m telescope, led to determination of the virtually entire C-star luminosity function for this system. | | | Several new C-star candidates were identified both by visual inspection of the frames using the SAO image tool and by means of a semi-automatic procedure developed by Gérard Muratorio (Muratorio and Azzopardi 1994) in the Munich Image Data Analysis System (MIDAS) environment. |
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http://www.cfht.hawaii.edu/Reference/Proceedings/azzopardi
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| | Castor 6 |
| | Castor Bb is a main sequence dwarf star of uncertain spectral type, probably ranging from M2 to a brighter type ("earlier") -- possibly with metallic lines as well -- and luminosity type V (Golub et al, 1983). | | | Castor Aa is a main sequence dwarf bluish-white star of spectral and luminosity type A1 V. Given its shared spectral type with well known neighbor Sirius A, Star Aa probably has a similar mass around 2.15 Solar. | | | The two binary pairs move in an eccentric orbit (e= 0.343) that is inclined by 114.5° from the perspective of an observer on Earth (Wulff Dieter Heintz, 1988). |
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http://www.solstation.com/stars2/castor6.htm
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| | DV Ursae Majoris: An Eclipsing Dwarf Nova |
| | When the white dwarf is in front you have a secondary maximum, where the light is brighter then the minimum but dimmer then when both stars are in view. | | | In DV Ursae Majoris, the primary, more massive star is a white dwarf and the secondary star is an M dwarf. | | | An accretion disk has formed that is fed by its secondary star, the M dwarf. |
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http://www.watson.ibm.com/leo/ScienceResearch/jjhs/hall2001.html
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| | white dwarf - Columbia Encyclopedia article about white dwarf |
| | The first white dwarf discovered (1844) was the faint companion in the binary star Sirius. | | | white dwarf, in astronomy, a type of star that is abnormally faint for its white-hot temperature (see mass-luminosity relation mass-luminosity relation, in astronomy, law stating that the luminosity of a star is proportional to some power of the mass of the star. | | | The existence of white dwarfs is intimately connected with stellar evolution stellar evolution, life history of a star, beginning with its condensation out of the interstellar gas (see interstellar matter) and ending, sometimes catastrophically, when the star has exhausted its nuclear fuel or can no longer adjust itself to a stable configuration. |
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http://columbia.thefreedictionary.com/white+dwarf
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| | Aquarius |
| | This phenomenon is caused by a very close binary system, which the larger star the cooler one, the small star(perhaps a white dwarf) the hot one. | | | Aquarius has a few nice binaries, a unique variable, and a few deep sky objects of some interest (but the Messiers here are generally sub-par). | | | Even if alpha Aquarii is a supergiant, perhaps a hundred times the size of the Sun, since it's a thousand light years away it only shines with a 2.96 visual magnitude. |
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http://www.dibonsmith.com/aqr_con.htm
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| | Discovery of Low-Luminosity Carbon Stars in the Fornax Dwarf Spheroidal Galaxy with MOS at CFHT |
| | C-Star Population in the Fornax Dwarf Spheroidal Galaxy | | | Several new C-star candidates were identified both by visual inspection of the frames using the SAO image tool and by means of a semi-automatic procedure developed by Gérard Muratorio (Muratorio and Azzopardi 1994) in the Munich Image Data Analysis System (MIDAS) environment. | | | However, the faint-ends of the C-star luminosity functions of more nearby extragalactic systems need to be taken into consideration to first confirm this trend and then to better constrain the aforementioned theory. |
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http://www.cfht.hawaii.edu/Reference/Proceedings/azzopardi
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| | * Draco - (Astronomy): Definition |
| | The HST images seem to indicate that the central star is actually a binary system and that the nebula we see today is actually the result of at least two separate events. | | | Tyl is a relatively dim star with a magnitude of 4. | | | Draco 's stars were circumpolar about 5000 BCE, and, like all those similarly situated, - of course few in number owing to the low latitude of the Nile country, - were much observed in early Egypt, although differently figured than as with us. |
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http://en.mimi.hu/astronomy/draco.html
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| | AAVSO IP Peg |
| | Currently, the accepted "disc instability" theory for dwarf nova outbursts (Osaki 1974) states that outbursts occur when, in normal (quiescent state) accretion, the surface density and temperature of the disc reach an unstable state; the temperature and radiation level then rise quickly and material stored in the disc is dumped onto the primary star. | | | By the peak of the dwarf nova outburst, the larger flux at mid-eclipse suggests that the outburst has spread to the outer disc and has grown so that it is visible around the limb of the secondary. | | | Just when you thought IP Peg couldn't get any more interesting we discover that it was the first star to show evidence of spiral arms in its accretion disc (Steeghs 1997)! |
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http://home.san.rr.com/rshobservatory/AAVSOIPPeg.htm
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| | APOD Search Results for "Dwarf Star" |
| | white dwarf stars in binary star systems are thought to draw enough mass from their companions to become unstable, triggering a nuclear detonation. | | | Trapezium is typical of young star clusters, then the survey results suggest that brown dwarfs and free-floating planets may be fairly common, but there are not enough to solve the mystery of dark matter in the Universe. | | | The gas is energized by the hot central star as it nears the end of its life, evolving toward a final white dwarf phase. |
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http://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search?Dwarf+Star
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| | Avior |
| | Canopus is massive enough that fusion reactions may proceed farther to produce a much rarer neon-oxygen white dwarf. | | | Canopus was originally the Alpha star of the ancient constellation Argo, the ship on which Jason sailed to find the golden fleece. | | | Canopus fell into Carina, and is therefore now Alpha Carinae. |
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http://www.astro.uiuc.edu/~kaler/sow/canopus.html
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| | Satellites and Tidal Streams - Abstracts |
| | The selected ensemble of low--mass dwarf galaxies was chosen to show prominent supergiant HI holes in their ISM which are considered to be tracers of past massive star formation. | | | I have computed the orbital angular momentum of the other satellite dwarfs with measured proper motions, and find they span more than three orders of magnitude, and cover a wide range of directions. | | | The ages of these systems showing the WR feature are well estimated, therefore, if an external companion object has induced the star formation, it must be near the burst and their interrelation probably very evident. |
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http://www.iac.es/proyect/sattail/sattail_abstracts.html
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| | The Star Formation History of the Carina Dwarf Spheroidal Galaxy |
| | We have obtained deep CCD photometry (limiting magnitude $V \sim 24.5$) of three fields in the Carina dwarf galaxy, reaching well below the main-sequence turnoff in each field. | | | We present the results of a detailed study of the turnoff region using a program we have developed which allows us to model various star formation scenarios. | | | By quantitatively comparing the synthetic results with the data, we can evaluate the feasibility of various star formation scenarios. |
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http://www.aas.org/publications/baas/v27n2/aas186/abs/S3902.html
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| | Gemini, a February Constellation |
| | Both stars are spectroscopic binaries, and small telescopes show a 9th magnitude red dwarf companion, which is itself an eclipsing binary star. | | | The primary star is a spectroscopic and occultation binary with a period of 8.17 years. | | | The brighter star is a spectroscopic binary with a 6.13 year period. |
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http://www.faster.co.nz/~rasnz/Stars/Gemini.htm
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| | * Ursa Minor - (Astronomy): Definition |
| | For example, we receive 100 times more light energy from Vega -- a zero- magnitude star -- than from Eta Ursa Minor -- a fifth- magnitude star in the Little Dipper. | | | For every five steps in magnitude, the apparent brightness of a star,, or changes by a factor of 100. | | | Under the clearest, darkest skies, your eye cannot see stars fainter than sixth magnitude. |
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http://en.mimi.hu/astronomy/ursa_minor.html
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| | Constellation Mythology - Perseus the hero |
| | Castor is the alpha star and is made up of two blue-white spectroscopic double-stars and a red dwarf double, so Castor is actually a total of six stars, two of which can be seen by small telescopes! | | | Pollux, the beta star, is a magnitude 1.1 yellow giant, 10 times the size of our Sun, and is actually brighter than Castor, even though Castor, at magnitude 1.6, is listed as the alpha star. | | | Besides Castor, one of the best doubles in Gemini is Mu, containing a magnitude 2.9 star and a magnitude 9.8 companion. |
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http://www.fvastro.org/articles/gemini.htm
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| | Dwarf galaxies of the Local Group |
| | In the case of Tucana, it was speculated that galactic winds expelled the interstellar medium at early epochs and halted star formation, a process apparently not dependent on environment. | | | A careful analysis based on extensive artificial star tests has given a metallicity dispersion | | | It therefore appears that the early star formation episode occurred in Phoenix on a larger spatial scale that subsequent bursts. |
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http://www.astro.ucla.edu/~ivo/research/PastResearch/node4.html
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| | GK Workshop - D. Martínez-Delgado & A. Aparicio |
| | If it belongs to Phoenix, this galaxy could be a good evidence that a burst of star formation can blow-out the gas from a dwarf galaxy, preventing further star formation (Dekel and Silk 1986). | | | It lacks obvious signs of current star formation, such as a conspicous bright, blue stellar population or H | | | Our Phoenix CMD shows that the recent star formation is located in the central 170 pc, in contrast with the complete absence of young stars in the outer region of the galaxy (see Martínez-Delgado et al. |
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http://www.astro.uni-bonn.de/~webgk/ws98/dmd_p.html
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| | GSAOI Dwarf Galaxies Science Page |
| | It is probably no exaggeration to claim that the most important outstanding question in the study of the formation and evolution of dwarf galaxies is the origin of the remarkable diversity of star formation histories observed among the dwarf Ellipticals (a class that includes the so-called dwarf Spheriodals) of the Local Group. | | | To make progress in understanding the processes that govern dwarf galaxy evolution, we need to study systems beyond the Local Group. | | | The existence of this system demonstrates that proximity to a large galaxy cannot be the only factor governing the evolution of dwarf galaxies. |
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http://msowww.anu.edu.au/gsaoi/science/dwarfs.shtml
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| | EF Eridani: Information From Answers.com |
| | The substellar mass in orbit around the white dwarf is a star which lost all of its gas to the white dwarf, except what remains, a 0.05 solar mass ball, which is too small to continue fusion, and does not have the composition of a super-planet, brown dwarf, or white dwarf. | | | The star system consists of a white dwarf star with a substellar massed former star in orbit. | | | EF Eridani (EF Eri, sometimes incorrectly referred to as EF Eridanus) is a variable star of the type known as polars, AM Herculis stars, or magnetic cataclysmic variable stars. |
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http://www.answers.com/topic/ef-eridani
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| | Capella 4 |
| | Capella D is a red dwarf star of spectral and luminosity type M4-5 V. It has about a tenth of Sol's mass, 25 to 30 percent of its diameter, and 0.05 percent of its luminosity. | | | For more information about stars including spectral and luminosity class codes, go to ChView's webpage on The Stars of the Milky Way. | | | (1931-93), this binary system was often designated as "Capella H" because the letters B through G were already used for faint field stars that are not gravitationally bound. |
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http://www.solstation.com/stars2/capella4.htm
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| | [sci.astro] Stars (Astronomy Frequently Asked Questions) (7/9) |
| | In the revised classification scheme, white dwarf designations still start with the letter D to indicate dwarf or "degenerate" stellar structure. | | | The upshot of all this is that we have "dwarf" stars of relatively high surface gravity, small radius, and low luminosity, and "giant" stars of low surface gravity, large radius, and high luminosity _and their spectra look different_. | | | When the spectra of white dwarfs were investigated in more detail, it proved impossible to categorize them neatly for one increasingly apparent reason: the surface compositions of white dwarfs varied enormously from star to star. |
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http://www.faqs.org/faqs/astronomy/faq/part7
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| | A Big Dwarf & the Monster meets the Master... |
| | I would find a few more object that night, then I would find myself involved in a arm-wrestling match with a giant dwarf. | | | This is a nice view, and can be confirmed by, not only the two galaxies and their proximity, but a nice little T shaped asterism of dim stars just northeast of a mag 11.5 star, also northeast of the galaxies. | | | The life saver here, for finding the galaxy is, it is on a line between Polaris and 23 Ursae Majoris, the star "beyond" the end star in the Big Dipper's bowl, as you continue out toward the head of the Great Bear. |
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http://observers.org/reports/99.06.12.2.html
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| | Gemini |
| | In fact, the entire system is comprised of six stars, including a red dwarf, Castor C, which slowly revolves around both Castor A and Castor B. This star is also a variable (and therefore catalogued as YY Gem). | | | This was the first binary system that was so recognised, in 1802 (or 1803, accounts vary) by William Herschel. | | | The star is a noted binary, discussed below. |
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http://www.dibonsmith.com/gem_con.htm
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| | Galaxies |
| | Occasionally, at irregular intervals given by chance, in any type of galaxies, a supernova occurs: This is a star suddenly brightning to a high luminosity which may well outshine the whole galaxy; the maximal absolute magnitude of a supernova may well reach -19 to -20 magnitudes. | | | Galaxies are large systems of stars and interstellar matter, typically containing several million to some trillion stars, of masses between several million and several trillion times that of our Sun, of an extension of a few thousands to several 100,000s light years, typically separated by millions of light years distance. | | | The most massive galaxies are giants which are a million times more massive than the lightest: Their mass range is from at most some million times that of our Sun in case of the smallest dwarfs, to several trillion solar masses in case of giants like M87 or M77. |
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http://www.seds.org/messier/galaxy.html
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| | Citebase - Dwarf Cepheids in the Carina Dwarf Spheroidal Galaxy |
| | The ratio of dwarf Cepheids to RR Lyr stars in Carina is 0.13 +/- 0.10, though this result is highly sensitive to the star-formation history of Carina and the evolution of the Horizontal Branch. | | | The thin red giant branch (RGB) of the Carina dwarf spheroidal galaxy appears at first sight quite puzzling and seemingly in contrast with the presence of several distinct bursts of star formation. | | | We have discovered 20 dwarf Cepheids (DC) in the Carina dSph galaxy from the analysis of individual CCD images obtained for a deep photometric study of the system. |
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http://citebase.eprints.org/cgi-bin/citations?id=oai%3AarXiv%2Eorg%3Aastro%2Dph%2F9807233
(1771 words)
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| | Catalogue: J/AJ/110/2166 |
| | We have used the pulsating stars to derive a true distance modulus of 19.67±0.15 for Sextans (or D=86±6kpc), where the error is primarily due to uncertainties in the luminosity-metallicity relation for RR Lyr stars. | | | This file × table2 65 161 Log of Sextans observations × table8 38 1038 B-band photometry of the Sextans variables × table9 38 560 V-band photometry of the Sextans variables × table10 72 2852 Photometry of non-variable stars in the deep Sextans images | | | We have identified 44 variables: 36 RR Lyr star, 6 anomalous Cepheids, one long-period red variable, all probable members of Sextans, and one foreground contact binary. |
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http://cdsweb.u-strasbg.fr/cgi-bin/Cat?J/AJ/110/2166
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| | * Canis Major - (Astronomy): Definition |
| | The first white dwarf ever to be discovered was found because it is a companion star to Sirius, a bright star in the constellation Canis Major. | | | Brightest star of the sky alpha CMa Binaries alpha CMa,... | | | Canis Major is a dwarf galaxy, which is being pulled into the Milky Way... |
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http://en.mimi.hu/astronomy/canis_major.html
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| | Citebase - Dwarf Cepheids in the Carina Dwarf Spheroidal Galaxy |
| | The ratio of dwarf Cepheids to RR Lyr stars in Carina is 0.13 +/- 0.10, though this result is highly sensitive to the star-formation history of Carina and the evolution of the Horizontal Branch. | | | The thin red giant branch (RGB) of the Carina dwarf spheroidal galaxy appears at first sight quite puzzling and seemingly in contrast with the presence of several distinct bursts of star formation. | | | We have discovered 20 dwarf Cepheids (DC) in the Carina dSph galaxy from the analysis of individual CCD images obtained for a deep photometric study of the system. |
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http://citebase.eprints.org/cgi-bin/citations?id=oai%3AarXiv%2Eorg%3Aastro%2Dph%2F9807233
(1771 words)
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| | Minnesota Technolog |
| | After delays resulting from mechanical problems with the Hubble Space Telescope, researchers continued their examination of dwarf galaxies in an effort to expand their understanding of the formation of stars. | | | Data collected from the GR8 dwarf galaxy suggested that star formation occurred in one region of the galaxy, moved to a different region, and then moved back to a region that has had previous star formation. | | | According to Skillman, because of the low occurrences of recent star formation, a pattern of movement in these galaxies could not be seen. |
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http://technolog.it.umn.edu/technolog/mayjun99/dwarf.html
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