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Theta Cassiopeiae

February 15, 2024

Theta Cassiopeiae or θ Cassiopeiae is a solitary[3] star in the northern constellation of Cassiopeia. It shares the traditional name Marfak /ˈmɑːrfæk/ with μ Cassiopeiae, positioned less than half a degree to the WSW,[11] which is derived from the Arabic term Al Marfik or Al Mirfaq (المرفق), meaning "the elbow".[12] At an apparent visual magnitude of 4.3,[2] Theta Cassiopeiae is visible to the naked eye. Based upon an annual parallax shift of 24.42 mas,[1] it is located about 134 light years from the Sun. It has a total annual proper motion of 0.227 arcseconds per year,[13] and is slowly drifting further away from the Sun with a radial velocity of 2.5 km/s.[5]

Theta Cassiopeiae
Location of θ Cassiopeiae (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Cassiopeia
Right ascension 01h 11m 06.16225s[1]
Declination +55° 08′ 59.6472″[1]
Apparent magnitude (V) 4.334[2]
Characteristics
Spectral type A7 V[3]
U−B color index +0.130[2]
B−V color index +0.170[2]
Variable type Suspected δ Sct[4]
Astrometry
Radial velocity (Rv)2.5±0.6[5] km/s
Proper motion (μ) RA: +226.77[1] mas/yr
Dec.: −18.75[1] mas/yr
Parallax (π)24.42 ± 0.24 mas[1]
Distance134 ± 1 ly
(41.0 ± 0.4 pc)
Absolute magnitude (MV)+1.28[6]
Details[7]
Mass1.83 M☉
Radius2.6[8] R☉
Surface gravity (log g)4.03±0.14 cgs
Temperature8,202±279 K
Rotational velocity (v sin i)103[9] km/s
Age650 Myr
Other designations
Marfak, θ Cas, 33 Cassiopeiae, BD+54°236, HD 6961, HIP 5542, HR 343, SAO 22070[10]
Database references
SIMBADdata

In Chinese, 閣道 (Gé Dào), meaning Flying Corridor, refers to an asterism consisting of θ Cassiopeiae, ι Cassiopeiae, ε Cassiopeiae, δ Cassiopeiae, ν Cassiopeiae and ο Cassiopeiae.[14] Consequently, θ Cassiopeiae itself is known as 閣道四 (Gé Dào sì, English: the Fourth Star of Flying Corridor.)[15]

This is an A-type main sequence star with a stellar classification of A7 V.[3] The measured angular diameter of this star is 0.58±0.02 mas,[16] which, at the estimated distance of this star, yields a physical size of about 2.6 times the radius of the Sun.[8] It is about 650[7] million years in age and is spinning with a projected rotational velocity of 103 km/s.[9] This is a candidate Vega-type system, which means it displays an infrared excess suggesting it has an orbiting debris disk.[17] It is a suspected Delta Scuti variable.[4]

The star appears to be a member of a leading tidal tail of the Hyades cluster.[18]

References edit

  1. ^ a b c d e f van Leeuwen, F. (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.
  2. ^ a b c d Oja, T. (August 1991), "UBV photometry of stars whose positions are accurately known. VI", Astronomy and Astrophysics Supplement Series, 89 (2): 415–419, Bibcode:1991A&AS...89..415O.
  3. ^ a b c Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
  4. ^ a b Frolov, M. S. (April 1970), "List of Probable Delta Scuti Stars", Information Bulletin on Variable Stars, 427: 1, Bibcode:1970IBVS..427....1F.
  5. ^ a b de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
  6. ^ Eggen, Olin J. (July 1998), "The Age Range of Hyades Stars", The Astronomical Journal, 116 (1): 284–292, Bibcode:1998AJ....116..284E, doi:10.1086/300413.
  7. ^ a b David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
  8. ^ a b Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, vol. 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1. The radius (R*) is given by:
     
  9. ^ a b Royer, F.; et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224, S2CID 18475298.
  10. ^ "* tet Cas". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-02-16.
  11. ^ Sinnott, Roger W.; Perryman, Michael A. C. (1997), Millennium Star Atlas, vol. 1, Sky Publishing Corporation and the European Space Agency, p. 64, ISBN 0-933346-84-0.
  12. ^ Allen, R. H. (1963), Star Names: Their Lore and Meaning (Reprint ed.), New York: Dover Publications Inc., p. 148, ISBN 0-486-21079-0, retrieved 2010-12-12
  13. ^ Lépine, Sébastien; Shara, Michael M. (March 2005), "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)", The Astronomical Journal, 129 (3): 1483–1522, arXiv:astro-ph/0412070, Bibcode:2005AJ....129.1483L, doi:10.1086/427854, S2CID 2603568.
  14. ^ (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
  15. ^ (in Chinese) 香港太空館 - 研究資源 - 亮星中英對照表 2011-01-30 at the Wayback Machine, Hong Kong Space Museum. Accessed on line November 23, 2010.
  16. ^ Richichi, A.; et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.
  17. ^ Song, Inseok; et al. (January 2001), "Ages of A-Type Vega-like Stars from uvbyβ Photometry", The Astrophysical Journal, 546 (1): 352–357, arXiv:astro-ph/0010102, Bibcode:2001ApJ...546..352S, doi:10.1086/318269, S2CID 18154947.
  18. ^ Röser, Siegfried; et al. (January 2019), "Hyades tidal tails revealed by Gaia DR2", Astronomy & Astrophysics, 621: 5, arXiv:1811.03845, Bibcode:2019A&A...621L...2R, doi:10.1051/0004-6361/201834608, S2CID 118909033, L2.

External links edit

  • Kaler, James B., "Theta Cassiopeiae", Stars, University of Illinois.</ref>

February 15, 2024
theta, cassiopeiae, cassiopeiae, solitary, star, northern, constellation, cassiopeia, shares, traditional, name, marfak, ɑːr, with, cassiopeiae, positioned, less, than, half, degree, which, derived, from, arabic, term, marfik, mirfaq, المرفق, meaning, elbow, a. Theta Cassiopeiae or 8 Cassiopeiae is a solitary 3 star in the northern constellation of Cassiopeia It shares the traditional name Marfak ˈ m ɑːr f ae k with m Cassiopeiae positioned less than half a degree to the WSW 11 which is derived from the Arabic term Al Marfik or Al Mirfaq المرفق meaning the elbow 12 At an apparent visual magnitude of 4 3 2 Theta Cassiopeiae is visible to the naked eye Based upon an annual parallax shift of 24 42 mas 1 it is located about 134 light years from the Sun It has a total annual proper motion of 0 227 arcseconds per year 13 and is slowly drifting further away from the Sun with a radial velocity of 2 5 km s 5 Theta CassiopeiaeLocation of 8 Cassiopeiae circled Observation dataEpoch J2000 0 Equinox J2000 0 ICRS Constellation CassiopeiaRight ascension 01h 11m 06 16225s 1 Declination 55 08 59 6472 1 Apparent magnitude V 4 334 2 CharacteristicsSpectral type A7 V 3 U B color index 0 130 2 B V color index 0 170 2 Variable type Suspected d Sct 4 AstrometryRadial velocity Rv 2 5 0 6 5 km sProper motion m RA 226 77 1 mas yr Dec 18 75 1 mas yrParallax p 24 42 0 24 mas 1 Distance134 1 ly 41 0 0 4 pc Absolute magnitude MV 1 28 6 Details 7 Mass1 83 M Radius2 6 8 R Surface gravity log g 4 03 0 14 cgsTemperature8 202 279 KRotational velocity v sin i 103 9 km sAge650 MyrOther designationsMarfak 8 Cas 33 Cassiopeiae BD 54 236 HD 6961 HIP 5542 HR 343 SAO 22070 10 Database referencesSIMBADdataIn Chinese 閣道 Ge Dao meaning Flying Corridor refers to an asterism consisting of 8 Cassiopeiae i Cassiopeiae e Cassiopeiae d Cassiopeiae n Cassiopeiae and o Cassiopeiae 14 Consequently 8 Cassiopeiae itself is known as 閣道四 Ge Dao si English the Fourth Star of Flying Corridor 15 This is an A type main sequence star with a stellar classification of A7 V 3 The measured angular diameter of this star is 0 58 0 02 mas 16 which at the estimated distance of this star yields a physical size of about 2 6 times the radius of the Sun 8 It is about 650 7 million years in age and is spinning with a projected rotational velocity of 103 km s 9 This is a candidate Vega type system which means it displays an infrared excess suggesting it has an orbiting debris disk 17 It is a suspected Delta Scuti variable 4 The star appears to be a member of a leading tidal tail of the Hyades cluster 18 References edit a b c d e f van Leeuwen F 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 d Oja T August 1991 UBV photometry of stars whose positions are accurately known VI Astronomy and Astrophysics Supplement Series 89 2 415 419 Bibcode 1991A amp AS 89 415O a b c Eggleton P P Tokovinin A A September 2008 A catalogue of multiplicity among bright stellar systems Monthly Notices of the Royal Astronomical Society 389 2 869 879 arXiv 0806 2878 Bibcode 2008MNRAS 389 869E doi 10 1111 j 1365 2966 2008 13596 x S2CID 14878976 a b Frolov M S April 1970 List of Probable Delta Scuti Stars Information Bulletin on Variable Stars 427 1 Bibcode 1970IBVS 427 1F a b de Bruijne J H J Eilers A C October 2012 Radial velocities for the HIPPARCOS Gaia Hundred Thousand Proper Motion project Astronomy amp Astrophysics 546 14 arXiv 1208 3048 Bibcode 2012A amp A 546A 61D doi 10 1051 0004 6361 201219219 S2CID 59451347 A61 Eggen Olin J July 1998 The Age Range of Hyades Stars The Astronomical Journal 116 1 284 292 Bibcode 1998AJ 116 284E doi 10 1086 300413 a b David Trevor J Hillenbrand Lynne A 2015 The Ages of Early Type Stars Stromgren Photometric Methods Calibrated Validated Tested and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets The Astrophysical Journal 804 2 146 arXiv 1501 03154 Bibcode 2015ApJ 804 146D doi 10 1088 0004 637X 804 2 146 S2CID 33401607 a b Lang Kenneth R 2006 Astrophysical formulae Astronomy and astrophysics library vol 1 3rd ed Birkhauser ISBN 3 540 29692 1 The radius R is given by 2 R 41 0 0 58 10 3 AU 0 0046491 AU R 5 1 R displaystyle begin aligned 2 cdot R amp frac 41 0 cdot 0 58 cdot 10 3 text AU 0 0046491 text AU R bigodot amp approx 5 1 cdot R bigodot end aligned nbsp a b Royer F et al February 2007 Rotational velocities of A type stars III Velocity distributions Astronomy and Astrophysics 463 2 671 682 arXiv astro ph 0610785 Bibcode 2007A amp A 463 671R doi 10 1051 0004 6361 20065224 S2CID 18475298 tet Cas SIMBAD Centre de donnees astronomiques de Strasbourg Retrieved 2017 02 16 Sinnott Roger W Perryman Michael A C 1997 Millennium Star Atlas vol 1 Sky Publishing Corporation and the European Space Agency p 64 ISBN 0 933346 84 0 Allen R H 1963 Star Names Their Lore and Meaning Reprint ed New York Dover Publications Inc p 148 ISBN 0 486 21079 0 retrieved 2010 12 12 Lepine Sebastien Shara Michael M March 2005 A Catalog of Northern Stars with Annual Proper Motions Larger than 0 15 LSPM NORTH Catalog The Astronomical Journal 129 3 1483 1522 arXiv astro ph 0412070 Bibcode 2005AJ 129 1483L doi 10 1086 427854 S2CID 2603568 in Chinese 中國星座神話 written by 陳久金 Published by 台灣書房出版有限公司 2005 ISBN 978 986 7332 25 7 in Chinese 香港太空館 研究資源 亮星中英對照表 Archived 2011 01 30 at the Wayback Machine Hong Kong Space Museum Accessed on line November 23 2010 Richichi A et al February 2005 CHARM2 An updated Catalog of High Angular Resolution Measurements Astronomy and Astrophysics 431 2 773 777 Bibcode 2005A amp A 431 773R doi 10 1051 0004 6361 20042039 Song Inseok et al January 2001 Ages of A Type Vega like Stars from uvbyb Photometry The Astrophysical Journal 546 1 352 357 arXiv astro ph 0010102 Bibcode 2001ApJ 546 352S doi 10 1086 318269 S2CID 18154947 Roser Siegfried et al January 2019 Hyades tidal tails revealed by Gaia DR2 Astronomy amp Astrophysics 621 5 arXiv 1811 03845 Bibcode 2019A amp A 621L 2R doi 10 1051 0004 6361 201834608 S2CID 118909033 L2 External links editKaler James B Theta Cassiopeiae Stars University of Illinois lt ref gt Retrieved from https en wikipedia org w index php title Theta Cassiopeiae amp oldid 1186518589, wikipedia, wiki, book, books, library,

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