Gamma Cassiopeiae, Latinized from γ Cassiopeiae, is a bright star at the center of the distinctive "W" asterism in the northern circumpolar constellation of Cassiopeia. Although it is a fairly bright star with an apparent visual magnitude that varies from 1.6 to 3.0, it has no traditional Arabic or Latin name. It sometimes goes by the informal name Navi.
Gamma Cassiopeiae is a Be star, a variable star, and a multiple star system. Based upon parallax measurements made by the Hipparcos satellite, it is located at a distance of roughly 550 light-years from Earth. Together with its common-proper-motion companion, HD 5408, the system could contain a total of eight stars.[12]
A light curve for Gamma Cassiopeiae, plotted from data published by Labadie-Bartz et al. (2021)[13]Amateur image of γ Cassiopeiae and the associated nebulae IC63 and IC59. The bright star due south of Gamma Cassiopeiae is HD 5408, a common proper motion companion. (Neil Michael Wyatt)
Gamma Cassiopeiae is an eruptive variable star, whose apparent magnitude changes irregularly from 1.6 at its brightest to 3.0 at its dimmest. It is the prototype of the class of Gamma Cassiopeiae variable stars. In the late 1930s it underwent what is described as a shell episode and the brightness increased to above magnitude 2.0, then dropped rapidly to 3.4.[14] It has since been gradually brightening back to around 2.2.[15] At maximum intensity, γ Cassiopeiae outshines both Schedar (α Cas; magnitude 2.25) and Caph (β Cas; 2.3).
Gamma Cassiopeiae is a rapidly spinning star with a projected rotational velocity of 472 km s−1, giving it a pronounced equatorial bulge. When combined with the star's high luminosity, the result is the ejection of matter that forms a hot circumstellar disk of gas. The emissions and brightness variations are apparently caused by this "decretion disk".
The spectrum of this massive star matches a stellar classification of B0.5 IVe. A luminosity class of IV identifies it as a subgiant star that has reached a stage of its evolution where it is exhausting the supply of hydrogen in its core region and transforming into a giant star. The 'e' suffix is used for stars that show emission lines of hydrogen in the spectrum, caused in this case by the circumstellar disk. This places it among a category known as Be stars; in fact, the first such star ever to be so designated.[16] It has 17 times the Sun's mass and is radiating as much energy as 34,000 Suns. At this rate of emission, the star has reached the end of its life as a late O-type main sequence star[citation needed] after a relatively brief 8 million years. The outer atmosphere has an intense effective temperature of 25,000 K, which is causing it to glow with a blue-white hue.
X-ray emission
Gamma Cassiopeiae is the prototype of a small group of stellar sources of X-ray radiation that is about 10 times stronger than emitted from other B or Be stars. The character of the X-ray spectrum is Be thermal, possibly emitted from plasmas of temperatures up to least ten million kelvins, and shows very short term and long-term cycles. Historically, it has been held that these X-rays might be excited by matter originating from the star, from a hot wind or a disk around the star, accreting onto the surface of a degenerate companion, such as a white dwarf or neutron star. However, there are difficulties with either of these hypotheses. For example, it is not clear that enough matter can be accreted by a white dwarf, at the distance of the purported secondary star implied by the orbital period, sufficient to power an X-ray emission of nearly 1033 erg/s or 100 YW. A neutron star could easily power this X-ray flux, but X-ray emission from neutron stars is known to be non-thermal, and thus in apparent variance with the spectral properties.
Evidence suggests that the X-rays may be associated with the Be star itself or caused by some complex interaction between the star and surrounding decretion disk. One line of evidence is that the X-ray production is known to vary on both short and long time scales with respect to various UV line and continuum changes associated with a B star or with circumstellar matter close to the star.[17][18] Moreover, the X-ray emissions exhibit long-term cycles that correlate with the light curves in the visible wavelengths.[19]
Gamma Cassiopeiae exhibits characteristics consistent with a strong disordered magnetic field. No field can be measured directly from the Zeeman effect because of the star's rotation-broadened spectral lines. Instead, the presence of this field is inferred from a robust periodic signal of 1.21 days that suggests a magnetic field rooted on the rotating star's surface. The star's UV and optical spectral lines show ripples moving from blue to red over several hours, which indicates clouds of matter being held frozen over the star's surface by strong magnetic fields. This evidence suggests that a magnetic field from the star is interacting with the decretion disk, resulting in the X-ray emission. A disk dynamo has been advanced as a mechanism to explain this modulation of the X-rays. However, difficulties remain with this mechanism, among which is that there are no disk dynamos known to exist in other stars, rendering this behavior more difficult to analyze.[20]
Companions
Gamma Cassiopeiae has three faint companions, listed in double star catalogues as components B, C, and D.[21][22][12] Star B is about 2 arc-seconds distant and magnitude 11, and has a similar space velocity to the bright primary, making it likely to be physically associated. Component C is magnitude 13, nearly an arc-minute distant,[23][24] and is listed in Gaia Early Data Release 3 as having a very different proper motion and being much more distant than Gamma Cassiopeiae.[25] Finally, component D, about 21 arc-minutes distant, is the naked-eye star HR 266 (HD 5408), itself a quadruple system.[12]
Gamma Cassiopeiae A, the bright primary, itself contains a spectroscopic binary with an orbital period of about 203.5 days and an eccentricity alternately reported as 0.26 and "near zero." The mass of the companion is believed to be about that of the Sun, but its nature is unclear. It has been proposed that it is a degenerate star or a hot helium star, but it seems unlikely that it is a normal star. Therefore, it is likely to be more evolved than the primary and to have transferred mass to it during an earlier stage of evolution.[4][26] Additionally, Hipparcos data show a "wobble" with an amplitude of about 150 mas, that may correspond to the orbit of a third star. This star would have an orbital period of at least 60 years.[27]
The Chinese nameTsih, "the whip" (Chinese: 策; pinyin: cè), is commonly associated with this star.[28][29] The name however originally referred to Kappa Cassiopeiae,[30][31] and Gamma Cassiopeiae was just one of four horses pulling the chariot of legendary charioteer Wangliang.[30] This representation was later changed to make Gamma the whip.[30]
The star was used as an easily identifiable navigational reference point during space missions and American astronautVirgil Ivan "Gus" Grissom nicknamed the star Navi after his own middle name spelled backwards.[32][33]
^ abcdevan Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600
^ abcNicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49, Bibcode:1978A&AS...34....1N
^ abSamus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007–2013)". VizieR On-line Data Catalog: B/gcvs. 1: 02025. Bibcode:2009yCat....102025S.
^ abcdeNemravová, J.; Harmanec, P.; Koubský, P.; Miroshnichenko, A.; Yang, S.; Šlechta, M.; Buil, C.; Korčáková, D.; Votruba, V. (2012). "Properties and nature of Be stars. 29. Orbital and long-term spectral variations of γ Cassiopeiae". Astronomy & Astrophysics. 537: A59. arXiv:1111.3761. Bibcode:2012A&A...537A..59N. doi:10.1051/0004-6361/201117922. S2CID 34272401.
^Wilson, Ralph Elmer (1953). "General Catalogue of Stellar Radial Velocities". Carnegie Institute Washington D.C. Publication. Bibcode:1953GCRV..C......0W.
^ abcdSigut, T. A. A.; Jones, C. E. (October 2007), "The Thermal Structure of the Circumstellar Disk Surrounding the Classical Be Star γ Cassiopeiae", Astrophysical Journal, 668 (1): 481–491, arXiv:0706.4036, Bibcode:2007ApJ...668..481S, doi:10.1086/521209, S2CID 14362961
^ abZorec, J.; Frémat, Y.; Cidale, L. (2005). "On the evolutionary status of Be stars. I. Field Be stars near the Sun". Astronomy and Astrophysics. 441 (1): 235–248. arXiv:astro-ph/0509119. Bibcode:2005A&A...441..235Z. doi:10.1051/0004-6361:20053051. S2CID 17592657.
^Falkner, David E. (2011). "The Autumn Constellations". The Mythology of the Night Sky. Patrick Moore's Practical Astronomy Series. pp. 139–162. doi:10.1007/978-1-4614-0137-7_8. ISBN978-1-4614-0136-0. S2CID 127279699.
^"CCDM J00567+6043AB -- Double or multiple star", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2009-04-13
^ abcHutter, D. J.; Tycner, C.; Zavala, R. T.; Benson, J. A.; Hummel, C. A.; Zirm, H. (2021). "Surveying the Bright Stars by Optical Interferometry. III. A Magnitude-limited Multiplicity Survey of Classical Be Stars". The Astrophysical Journal Supplement Series. 257 (2): 69. arXiv:2109.06839. Bibcode:2021ApJS..257...69H. doi:10.3847/1538-4365/ac23cb. S2CID 237503492.
^Labadie-Bartz, Jonathan; Baade, Dietrich; Carciofi, Alex C.; Rubio, Amanda; Rivinius, Thomas; Borre, Camilla C.; Martayan, Christophe; Siverd, Robert J. (March 2021). "Short-term variability and mass loss in Be stars – VI. Frequency groups in γ Cas detected by TESS". Monthly Notices of the Royal Astronomical Society. 502 (1): 242–259. doi:10.1093/mnras/staa3913.
^Baldwin, Ralph B.; Torp-Smith, Robert (1941). "Light Curves of Gamma Cassiopeiae". Popular Astronomy. 49: 127. Bibcode:1941PA.....49..127B.
^Pollmann, E.; Vollmann, W.; Henry, G. W. (2014). "Long-term monitoring of Halpha emission strength and photometric V magnitude of gamma Cas". Information Bulletin on Variable Stars. 6109: 1. Bibcode:2014IBVS.6109....1P.
^Merrill, P. W.; Humason, M. L.; Burwell, C. G. (1925). "Discovery and Observations of Stars of Class Be". Astrophysical Journal. 61: 389. Bibcode:1925ApJ....61..389M. doi:10.1086/142899.
^Smith, M. A.; Robinson, R. D. (1999), "A multiwavelength campaign on γ Cassiopeiae. III. The case for magnetically controlled circumstellar kinematics", Astrophysical Journal, 517 (2): 866–882, Bibcode:1999ApJ...517..866S, doi:10.1086/307216, S2CID 122521231
^Cranmer, S.; Smith, M.; Robinson, R. (2000), "A Multiwavelength Campaign on γ Cassiopeiae. IV. The Case for Illuminated Disk-enhanced Wind Streams", Astrophysical Journal, 537 (1): 433–447, Bibcode:2000ApJ...537..433C, doi:10.1086/309008
^Smith, Myron A.; Cohen, David H.; Gu, Ming Feng; Robinson, Richard D.; Evans, Nancy Remage; Schran, Prudence G. (2004), "High-Resolution Chandra Spectroscopy of γ Cassiopeiae (B0.5e)", Astrophysical Journal, 600 (2): 972–985, arXiv:astro-ph/0309293, Bibcode:2004ApJ...600..972S, doi:10.1086/379873, S2CID 166002
^Robinson, R. D.; Smith, M. A.; Henry, G. W. (2002), "X-Ray and Optical Variations in the Classical Be Star γ Cassiopeia: The Discovery of a Possible Magnetic Dynamo", Astrophysical Journal, 575 (1): 435–448, arXiv:astro-ph/0205278, Bibcode:2002ApJ...575..435R, doi:10.1086/341141, S2CID 119495841
^Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920.
^Aitken, Robert Grant; Doolittle, Eric (1932). New general catalogue of double stars within 120° of the North pole. Carnegie Institution of Washington. Bibcode:1932ngcd.book.....A.
^Dommanget, J.; Nys, O. (1994). "Catalogue des composantes d'etoiles doubles et multiples (CCDM) premiere edition - Catalogue of the components of double and multiple stars (CCDM) first edition". Com. De l'Observ. Royal de Belgique. 115: 1. Bibcode:1994CoORB.115....1D.
^Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
^Miroschnichenko, A. S.; Bjorkman, K. S.; Krugov, V. D. (2002), "Binary nature and long term nature of Gamma Cassiopeiae", Publications of the Astronomical Society of the Pacific, 114 (801): 1226, Bibcode:2002PASP..114.1226M, doi:10.1086/342766
^Gontcharov, G. A.; et al. (2000). "New astrometric binaries among HIPPARCOS stars". Astronomy and Astrophysics. 355: 1164. Bibcode:2000A&A...355.1164G.
^唐山 (Tángshān) (1967). 天文學太空航空學辭典 [Dictionary of astronomy and astronautics] (in Chinese). 廣文書局. OCLC 22797568.
^Allen, Richard Hinckley (1963) [1899]. Star-names and their meanings. New York, NY: Dover Publications. p. 146. ISBN978-1-931559-44-7.
^ abcRidpath, Ian (1988). "Cassiopeia". Star Tales. James Clarke & Co. ISBN9780718826956.
^Sun, Xiaochun; Kistemaker, Jacob (1997). The Chinese Sky During the Han: Constellating Stars and Society. Leiden, New York, Köln: Koninklijke Brill. pp. 150, 168. ISBN9789004107373.
^"Post-landing Activities", Apollo 15 Lunar Surface Journal, NASA commentary at 105:11:33
^Apollo 10 Flown CSM Star Chart Directly from the Personal Collection of Mission Command Module Pilot John Young, Heritage Auction Galleries, retrieved March 11, 2010
External links
Philippe Stee's homepage: Hot and Active Stars Research
gamma, cassiopeiae, latinized, from, cassiopeiae, bright, star, center, distinctive, asterism, northern, circumpolar, constellation, cassiopeia, although, fairly, bright, star, with, apparent, visual, magnitude, that, varies, from, traditional, arabic, latin, . Gamma Cassiopeiae Latinized from g Cassiopeiae is a bright star at the center of the distinctive W asterism in the northern circumpolar constellation of Cassiopeia Although it is a fairly bright star with an apparent visual magnitude that varies from 1 6 to 3 0 it has no traditional Arabic or Latin name It sometimes goes by the informal name Navi g CassiopeiaeLocation of g Cassiopeiae circled Observation dataEpoch J2000 Equinox J2000Constellation CassiopeiaRight ascension 00h 56m 42 50108s 1 Declination 60 43 00 2984 1 Apparent magnitude V 2 47 2 1 6 3 0 3 CharacteristicsSpectral type B0 5IVe 4 U B color index 1 08 2 B V color index 0 15 2 Variable type g Cas 3 AstrometryRadial velocity Rv 6 8 5 km sProper motion m RA 25 17 1 mas yr Dec 3 92 1 mas yrParallax p 5 94 0 12 mas 1 Distance550 10 ly 168 3 pc Absolute magnitude MV 3 98 6 Orbit 4 PrimaryAaCompanionAbPeriod P 203 523 0 076 dEccentricity e 0Inclination i 45 Semi amplitude K1 primary 4 297 0 090 km sOrbit 7 PrimaryAabCompanionAcPeriod P 60 0 yrSemi major axis a 0 15 DetailsAaMass13 4 M Radius10 8 R Luminosity34 000 8 L Surface gravity log g 3 50 8 cgsTemperature25 000 8 KRotational velocity v sin i 432 9 km sAge8 0 0 4 9 MyrAbMass0 98 4 M Other designationsTsih 10 g Cas 27 Cassiopeiae ADS 782 BD 59 144 FK5 32 HD 5394 HIP 4427 HR 264 SAO 11482 WDS 00567 6043 AAVSO 0050 60 11 Database referencesSIMBADdataGamma Cassiopeiae is a Be star a variable star and a multiple star system Based upon parallax measurements made by the Hipparcos satellite it is located at a distance of roughly 550 light years from Earth Together with its common proper motion companion HD 5408 the system could contain a total of eight stars 12 Contents 1 Physical properties 1 1 X ray emission 2 Companions 3 Names 4 See also 5 References 6 External linksPhysical properties Edit A light curve for Gamma Cassiopeiae plotted from data published by Labadie Bartz et al 2021 13 Amateur image of g Cassiopeiae and the associated nebulae IC63 and IC59 The bright star due south of Gamma Cassiopeiae is HD 5408 a common proper motion companion Neil Michael Wyatt Gamma Cassiopeiae is an eruptive variable star whose apparent magnitude changes irregularly from 1 6 at its brightest to 3 0 at its dimmest It is the prototype of the class of Gamma Cassiopeiae variable stars In the late 1930s it underwent what is described as a shell episode and the brightness increased to above magnitude 2 0 then dropped rapidly to 3 4 14 It has since been gradually brightening back to around 2 2 15 At maximum intensity g Cassiopeiae outshines both Schedar a Cas magnitude 2 25 and Caph b Cas 2 3 Gamma Cassiopeiae is a rapidly spinning star with a projected rotational velocity of 472 km s 1 giving it a pronounced equatorial bulge When combined with the star s high luminosity the result is the ejection of matter that forms a hot circumstellar disk of gas The emissions and brightness variations are apparently caused by this decretion disk The spectrum of this massive star matches a stellar classification of B0 5 IVe A luminosity class of IV identifies it as a subgiant star that has reached a stage of its evolution where it is exhausting the supply of hydrogen in its core region and transforming into a giant star The e suffix is used for stars that show emission lines of hydrogen in the spectrum caused in this case by the circumstellar disk This places it among a category known as Be stars in fact the first such star ever to be so designated 16 It has 17 times the Sun s mass and is radiating as much energy as 34 000 Suns At this rate of emission the star has reached the end of its life as a late O type main sequence star citation needed after a relatively brief 8 million years The outer atmosphere has an intense effective temperature of 25 000 K which is causing it to glow with a blue white hue X ray emission Edit Gamma Cassiopeiae is the prototype of a small group of stellar sources of X ray radiation that is about 10 times stronger than emitted from other B or Be stars The character of the X ray spectrum is Be thermal possibly emitted from plasmas of temperatures up to least ten million kelvins and shows very short term and long term cycles Historically it has been held that these X rays might be excited by matter originating from the star from a hot wind or a disk around the star accreting onto the surface of a degenerate companion such as a white dwarf or neutron star However there are difficulties with either of these hypotheses For example it is not clear that enough matter can be accreted by a white dwarf at the distance of the purported secondary star implied by the orbital period sufficient to power an X ray emission of nearly 1033 erg s or 100 YW A neutron star could easily power this X ray flux but X ray emission from neutron stars is known to be non thermal and thus in apparent variance with the spectral properties Evidence suggests that the X rays may be associated with the Be star itself or caused by some complex interaction between the star and surrounding decretion disk One line of evidence is that the X ray production is known to vary on both short and long time scales with respect to various UV line and continuum changes associated with a B star or with circumstellar matter close to the star 17 18 Moreover the X ray emissions exhibit long term cycles that correlate with the light curves in the visible wavelengths 19 Gamma Cassiopeiae exhibits characteristics consistent with a strong disordered magnetic field No field can be measured directly from the Zeeman effect because of the star s rotation broadened spectral lines Instead the presence of this field is inferred from a robust periodic signal of 1 21 days that suggests a magnetic field rooted on the rotating star s surface The star s UV and optical spectral lines show ripples moving from blue to red over several hours which indicates clouds of matter being held frozen over the star s surface by strong magnetic fields This evidence suggests that a magnetic field from the star is interacting with the decretion disk resulting in the X ray emission A disk dynamo has been advanced as a mechanism to explain this modulation of the X rays However difficulties remain with this mechanism among which is that there are no disk dynamos known to exist in other stars rendering this behavior more difficult to analyze 20 Companions EditGamma Cassiopeiae has three faint companions listed in double star catalogues as components B C and D 21 22 12 Star B is about 2 arc seconds distant and magnitude 11 and has a similar space velocity to the bright primary making it likely to be physically associated Component C is magnitude 13 nearly an arc minute distant 23 24 and is listed in Gaia Early Data Release 3 as having a very different proper motion and being much more distant than Gamma Cassiopeiae 25 Finally component D about 21 arc minutes distant is the naked eye star HR 266 HD 5408 itself a quadruple system 12 Gamma Cassiopeiae A the bright primary itself contains a spectroscopic binary with an orbital period of about 203 5 days and an eccentricity alternately reported as 0 26 and near zero The mass of the companion is believed to be about that of the Sun but its nature is unclear It has been proposed that it is a degenerate star or a hot helium star but it seems unlikely that it is a normal star Therefore it is likely to be more evolved than the primary and to have transferred mass to it during an earlier stage of evolution 4 26 Additionally Hipparcos data show a wobble with an amplitude of about 150 mas that may correspond to the orbit of a third star This star would have an orbital period of at least 60 years 27 Names Editg Cassiopeiae Latinized to Gamma Cassiopeiae is the object s Bayer designation and it has the Flamsteed designation 27 Cassiopeiae The Chinese name Tsih the whip Chinese 策 pinyin ce is commonly associated with this star 28 29 The name however originally referred to Kappa Cassiopeiae 30 31 and Gamma Cassiopeiae was just one of four horses pulling the chariot of legendary charioteer Wangliang 30 This representation was later changed to make Gamma the whip 30 The star was used as an easily identifiable navigational reference point during space missions and American astronaut Virgil Ivan Gus Grissom nicknamed the star Navi after his own middle name spelled backwards 32 33 See also EditIota Ursae Majoris informally named Dnoces for astronaut Ed White Gamma Velorum informally named Regor for astronaut Roger B ChaffeeReferences Edit a b c d e van Leeuwen F November 2007 Validation of the new Hipparcos reduction Astronomy and Astrophysics 474 2 653 664 arXiv 0708 1752 Bibcode 2007A amp A 474 653V doi 10 1051 0004 6361 20078357 S2CID 18759600 a b c Nicolet B 1978 Photoelectric photometric Catalogue of homogeneous measurements in the UBV System Astronomy and Astrophysics Supplement Series 34 1 49 Bibcode 1978A amp AS 34 1N a b Samus N N Durlevich O V et al 2009 VizieR Online Data Catalog General Catalogue of Variable Stars Samus 2007 2013 VizieR On line Data Catalog B gcvs 1 02025 Bibcode 2009yCat 102025S a b c d e Nemravova J Harmanec P Koubsky P Miroshnichenko A Yang S Slechta M Buil C Korcakova D Votruba V 2012 Properties and nature of Be stars 29 Orbital and long term spectral variations of g Cassiopeiae Astronomy amp Astrophysics 537 A59 arXiv 1111 3761 Bibcode 2012A amp A 537A 59N doi 10 1051 0004 6361 201117922 S2CID 34272401 Wilson Ralph Elmer 1953 General Catalogue of Stellar Radial Velocities Carnegie Institute Washington D C Publication Bibcode 1953GCRV C 0W Anderson E Francis Ch 2012 XHIP An extended hipparcos compilation Astronomy Letters 38 5 331 arXiv 1108 4971 Bibcode 2012AstL 38 331A doi 10 1134 S1063773712050015 S2CID 119257644 Tokovinin Andrei 2018 03 01 The Updated Multiple Star Catalog The Astrophysical Journal Supplement Series 235 1 6 arXiv 1712 04750 Bibcode 2018ApJS 235 6T doi 10 3847 1538 4365 aaa1a5 ISSN 0067 0049 S2CID 119047709 a b c d Sigut T A A Jones C E October 2007 The Thermal Structure of the Circumstellar Disk Surrounding the Classical Be Star g Cassiopeiae Astrophysical Journal 668 1 481 491 arXiv 0706 4036 Bibcode 2007ApJ 668 481S doi 10 1086 521209 S2CID 14362961 a b Zorec J Fremat Y Cidale L 2005 On the evolutionary status of Be stars I Field Be stars near the Sun Astronomy and Astrophysics 441 1 235 248 arXiv astro ph 0509119 Bibcode 2005A amp A 441 235Z doi 10 1051 0004 6361 20053051 S2CID 17592657 Falkner David E 2011 The Autumn Constellations The Mythology of the Night Sky Patrick Moore s Practical Astronomy Series pp 139 162 doi 10 1007 978 1 4614 0137 7 8 ISBN 978 1 4614 0136 0 S2CID 127279699 CCDM J00567 6043AB Double or multiple star SIMBAD Centre de Donnees astronomiques de Strasbourg retrieved 2009 04 13 a b c Hutter D J Tycner C Zavala R T Benson J A Hummel C A Zirm H 2021 Surveying the Bright Stars by Optical Interferometry III A Magnitude limited Multiplicity Survey of Classical Be Stars The Astrophysical Journal Supplement Series 257 2 69 arXiv 2109 06839 Bibcode 2021ApJS 257 69H doi 10 3847 1538 4365 ac23cb S2CID 237503492 Labadie Bartz Jonathan Baade Dietrich Carciofi Alex C Rubio Amanda Rivinius Thomas Borre Camilla C Martayan Christophe Siverd Robert J March 2021 Short term variability and mass loss in Be stars VI Frequency groups in g Cas detected by TESS Monthly Notices of the Royal Astronomical Society 502 1 242 259 doi 10 1093 mnras staa3913 Baldwin Ralph B Torp Smith Robert 1941 Light Curves of Gamma Cassiopeiae Popular Astronomy 49 127 Bibcode 1941PA 49 127B Pollmann E Vollmann W Henry G W 2014 Long term monitoring of Halpha emission strength and photometric V magnitude of gamma Cas Information Bulletin on Variable Stars 6109 1 Bibcode 2014IBVS 6109 1P Merrill P W Humason M L Burwell C G 1925 Discovery and Observations of Stars of Class Be Astrophysical Journal 61 389 Bibcode 1925ApJ 61 389M doi 10 1086 142899 Smith M A Robinson R D 1999 A multiwavelength campaign on g Cassiopeiae III The case for magnetically controlled circumstellar kinematics Astrophysical Journal 517 2 866 882 Bibcode 1999ApJ 517 866S doi 10 1086 307216 S2CID 122521231 Cranmer S Smith M Robinson R 2000 A Multiwavelength Campaign on g Cassiopeiae IV The Case for Illuminated Disk enhanced Wind Streams Astrophysical Journal 537 1 433 447 Bibcode 2000ApJ 537 433C doi 10 1086 309008 Smith Myron A Cohen David H Gu Ming Feng Robinson Richard D Evans Nancy Remage Schran Prudence G 2004 High Resolution Chandra Spectroscopy of g Cassiopeiae B0 5e Astrophysical Journal 600 2 972 985 arXiv astro ph 0309293 Bibcode 2004ApJ 600 972S doi 10 1086 379873 S2CID 166002 Robinson R D Smith M A Henry G W 2002 X Ray and Optical Variations in the Classical Be Star g Cassiopeia The Discovery of a Possible Magnetic Dynamo Astrophysical Journal 575 1 435 448 arXiv astro ph 0205278 Bibcode 2002ApJ 575 435R doi 10 1086 341141 S2CID 119495841 Mason Brian D Wycoff Gary L Hartkopf William I Douglass Geoffrey G Worley Charles E 2001 The 2001 US Naval Observatory Double Star CD ROM I The Washington Double Star Catalog The Astronomical Journal 122 6 3466 Bibcode 2001AJ 122 3466M doi 10 1086 323920 Aitken Robert Grant Doolittle Eric 1932 New general catalogue of double stars within 120 of the North pole Carnegie Institution of Washington Bibcode 1932ngcd book A Hipparcos catalogue record VizieR Retrieved 2009 04 13 Dommanget J Nys O 1994 Catalogue des composantes d etoiles doubles et multiples CCDM premiere edition Catalogue of the components of double and multiple stars CCDM first edition Com De l Observ Royal de Belgique 115 1 Bibcode 1994CoORB 115 1D Brown A G A et al Gaia collaboration 2021 Gaia Early Data Release 3 Summary of the contents and survey properties Astronomy amp Astrophysics 649 A1 arXiv 2012 01533 Bibcode 2021A amp A 649A 1G doi 10 1051 0004 6361 202039657 S2CID 227254300 Erratum doi 10 1051 0004 6361 202039657e Gaia EDR3 record for this source at VizieR Miroschnichenko A S Bjorkman K S Krugov V D 2002 Binary nature and long term nature of Gamma Cassiopeiae Publications of the Astronomical Society of the Pacific 114 801 1226 Bibcode 2002PASP 114 1226M doi 10 1086 342766 Gontcharov G A et al 2000 New astrometric binaries among HIPPARCOS stars Astronomy and Astrophysics 355 1164 Bibcode 2000A amp A 355 1164G 唐山 Tangshan 1967 天文學太空航空學辭典 Dictionary of astronomy and astronautics in Chinese 廣文書局 OCLC 22797568 Allen Richard Hinckley 1963 1899 Star names and their meanings New York NY Dover Publications p 146 ISBN 978 1 931559 44 7 a b c Ridpath Ian 1988 Cassiopeia Star Tales James Clarke amp Co ISBN 9780718826956 Sun Xiaochun Kistemaker Jacob 1997 The Chinese Sky During the Han Constellating Stars and Society Leiden New York Koln Koninklijke Brill pp 150 168 ISBN 9789004107373 Post landing Activities Apollo 15 Lunar Surface Journal NASA commentary at 105 11 33 Apollo 10 Flown CSM Star Chart Directly from the Personal Collection of Mission Command Module Pilot John Young Heritage Auction Galleries retrieved March 11 2010External links EditPhilippe Stee s homepage Hot and Active Stars Research Gamma Cassiopeiae and the Be Stars A New Class of X ray Star Gamma Cas and Friends Astronomy Picture of the Day 2009 December 24 Retrieved from https en wikipedia org w index php title Gamma Cassiopeiae amp oldid 1170470225, wikipedia, wiki, book, books, library,
