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HR 4729

January 01, 1970

HR 4729 (HD 108250) is a multiple star system located about 95 parsecs (310 ly) from the Sun in the constellation of Crux and part of the asterism known as the Southern Cross. It is a close companion of α Crucis and sometimes called α Crucis C.

HR 4729
Observation data
Epoch J2000      Equinox J2000
Constellation Crux
Right ascension 12h 26m 30.8790s[1]
Declination −63° 07′ 19.993″[1]
Apparent magnitude (V) 4.79[2]
Characteristics
Spectral type B5 V[3]
U−B color index −0.59[4]
B−V color index −0.12[4]
Astrometry
Radial velocity (Rv)+27[5] km/s
Proper motion (μ) RA: −39.593[6] mas/yr
Dec.: −14.537[6] mas/yr
Parallax (π)10.5623 ± 0.2340 mas[6]
Distance309 ± 7 ly
(95 ± 2 pc)
Absolute magnitude (MV)−0.98[2]
Orbit[7]
Period (P)1.225155±0.000005 d
Eccentricity (e)0.024±0.014
Periastron epoch (T)2438903.314±0.003 JD
Argument of periastron (ω)
(secondary)		314±34°
Semi-amplitude (K1)
(primary)		43.1±0.6 km/s
Details
Mass9.65[8] M☉
Radius5.5[9] R☉
Rotational velocity (v sin i)131[10] km/s
Age12[11] Myr
Other designations
HR 4729, CPD−62°2742, GC 16951, 25 G. Crucis, WDS J12266-6306C, CCDM J12266-6306C
Database references
SIMBADdata

Nomenclature edit

HR 4729 is the star's designation in the Bright Star Catalogue. It is also often referred to by its Henry Draper Catalogue listing of HD 108250. Because of its closeness to α Crucis it is included in many multiple star catalogues as α Crucis C.[12] It is also listed as star 25 in Crux in the Uranometria Argentina, displayed as 25 G. Crucis.[13]

Discovery edit

HR 4729 was first observed in 1829, as a companion to α Crucis, by James Dunlop from Paramatta in New South Wales.[14] As early as 1916, HR 4729 was reported to have a variable radial velocity indicating a likely binary system, but the orbital elements were not calculated until 1979.[7]

System edit

 
α Crucis with HR 4729 close by

HR 4729 lies 90 arcseconds away from the triple star system of α Crucis and shares its motion through space, suggesting it may be gravitationally bound to it, and it is therefore generally assumed to be physically associated. In the context of being a companion to α Crucis it is usually referred to as α Crucis C.[15][16]

HR 4729 is itself a close spectroscopic binary system with a period of 1 day 5 hours. It also has a faint visual companion 2.1" away. A further seven faint stars are also listed as members of the α Crucis group out to a distance of about two arc-minutes.[12] One particular companion very close to HR 4729 has been resolved using adaptive optics at infrared wavelengths. It has been named α Crucis P, or α Crucis CP because it is only 2" from HR 4729.[11]

Rizzuto and colleagues determined in 2011 that the α Crucis system, including HR 4729, was 66% likely to be a member of the Lower Centaurus–Crux sub-group of the Scorpius–Centaurus association. It was not previously seen to be a member of the group because of confusion over the true radial velocity of the spectroscopic pair.[17]

On 2008 October 2, the Cassini–Huygens spacecraft resolved three of the components (A, B and C) of the multiple star system as Saturn's disk occulted it.[18][19]

Stellar properties edit

HR 4729 is a hot class B main sequence star nearly ten times as massive as the sun. It is only about twelve million years old, but already shows signs of evolving away from the main sequence. Several studies have assigned a subgiant luminosity class to the star.[7][20]

The spectroscopic companion cannot be seen in the spectrum, therefore little is known about its properties. Analysis of the orbit shows that it has a mass greater than the sun.[8]

The physically associated companion α Crucis D or α Crucis CP is a 15th magnitude star. Its relative faintness suggests an M0 V spectral type.[8] Two other, even fainter stars, lie within 10″ of HR 4729.[12]

References edit

  1. ^ a b Hog, E.; Kuzmin, A.; Bastian, U.; Fabricius, C.; Kuimov, K.; Lindegren, L.; Makarov, V. V.; Roeser, S. (1998). "The TYCHO Reference Catalogue". Astronomy and Astrophysics. 335: L65. Bibcode:1998A&A...335L..65H.
  2. ^ a b Kaltcheva, N. T.; Golev, V. K.; Moran, K. (2014). "Massive stellar content of the Galactic supershell GSH 305+01-24". Astronomy & Astrophysics. 562: A69. arXiv:1312.5592. Bibcode:2014A&A...562A..69K. doi:10.1051/0004-6361/201321454. S2CID 54222753.
  3. ^ Corbally, C. J. (1984). "Close visual binaries. I - MK classifications". Astrophysical Journal Supplement Series. 55: 657. Bibcode:1984ApJS...55..657C. doi:10.1086/190973.
  4. ^ a b Stagg, Christopher (1987). "A photometric survey of the bright southern Be stars". Monthly Notices of the Royal Astronomical Society. 227: 213–240. Bibcode:1987MNRAS.227..213S. doi:10.1093/mnras/227.1.213.
  5. ^ Wilson, Ralph Elmer (1953). "General Catalogue of Stellar Radial Velocities". Carnegie Institute Washington D.C. Publication. Washington: Carnegie Institution of Washington. Bibcode:1953GCRV..C......0W.
  6. ^ a b c Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  7. ^ a b c Hernandez, C. A.; De Hernandez, E. B. (1979). "The orbital elements of 25 G Crucis /HD 108250/". Revista Mexicana de Astronomía y Astrofísica. 4: 297. Bibcode:1979RMxAA...4..297H.
  8. ^ a b c Tokovinin, A. A. (1997). "MSC - a catalogue of physical multiple stars". Astronomy and Astrophysics Supplement Series. 124 (1): 75–84. Bibcode:1997A&AS..124...75T. doi:10.1051/aas:1997181. ISSN 0365-0138.
  9. ^ Brown, A. G. A.; Verschueren, W. (1997). "High S/N Echelle spectroscopy in young stellar groups. II. Rotational velocities of early-type stars in SCO OB2". Astronomy and Astrophysics. 319: 811. arXiv:astro-ph/9608089. Bibcode:1997A&A...319..811B.
  10. ^ a b Tokovinin, A. A.; Chalabaev, A.; Shatsky, N. I.; Beuzit, J. L. (1999). "A near IR adaptive optics search for faint companions to early-type multiple stars". Astronomy and Astrophysics. 346: 481. Bibcode:1999A&A...346..481T.
  11. ^ a b c 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.
  12. ^ Gould, Benjamin Apthorp (1879). "Uranometria Argentina: Brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral: Con atlas". Resultados del Observatorio Nacional Argentino en Cordoba. 1. Bibcode:1879RNAO....1.....G.
  13. ^ Dunlop, James (1829). "Approximate Places of Double Stars in the Southern Hemisphere, observed at Paramatta in New South Wales". Memoirs of the Royal Astronomical Society. 3: 257. Bibcode:1829MmRAS...3..257D.
  14. ^ Shatsky, N.; Tokovinin, A. (2002). "The mass ratio distribution of B-type visual binaries in the Sco OB2 association". Astronomy and Astrophysics. 382: 92–103. arXiv:astro-ph/0109456. Bibcode:2002A&A...382...92S. doi:10.1051/0004-6361:20011542. S2CID 16697655.
  15. ^ Eggleton, Peter; Tokovinin, A. (2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
  16. ^ Rizzuto, Aaron; Ireland, Michael; Robertson, J. G. (October 2011), "Multidimensional Bayesian membership analysis of the Sco OB2 moving group", Monthly Notices of the Royal Astronomical Society, 416 (4): 3108–3117, arXiv:1106.2857, Bibcode:2011MNRAS.416.3108R, doi:10.1111/j.1365-2966.2011.19256.x, S2CID 54510608.
  17. ^ NASA/JPL/Space Science Institute. Multimedia - Images - Raw Images 2008-10-25 at the Wayback Machine. Retrieved 2008-10-21
  18. ^ Cassini "Kodak Moments" - Unmanned Spaceflight.com. Retrieved 2008-10-21
  19. ^ Hiltner, W. A.; Garrison, R. F.; Schild, R. E. (1969). "MK Spectral Types for Bright Southern OB Stars". Astrophysical Journal. 157: 313. Bibcode:1969ApJ...157..313H. doi:10.1086/150069.

External links edit


January 01, 1970
4729, 108250, multiple, star, system, located, about, parsecs, from, constellation, crux, part, asterism, known, southern, cross, close, companion, crucis, sometimes, called, crucis, observation, dataepoch, j2000, equinox, j2000, constellation, crux, right, as. HR 4729 HD 108250 is a multiple star system located about 95 parsecs 310 ly from the Sun in the constellation of Crux and part of the asterism known as the Southern Cross It is a close companion of a Crucis and sometimes called a Crucis C HR 4729 Observation dataEpoch J2000 Equinox J2000 Constellation Crux Right ascension 12h 26m 30 8790s 1 Declination 63 07 19 993 1 Apparent magnitude V 4 79 2 Characteristics Spectral type B5 V 3 U B color index 0 59 4 B V color index 0 12 4 AstrometryRadial velocity Rv 27 5 km sProper motion m RA 39 593 6 mas yr Dec 14 537 6 mas yrParallax p 10 5623 0 2340 mas 6 Distance309 7 ly 95 2 pc Absolute magnitude MV 0 98 2 Orbit 7 Period P 1 225155 0 000005 dEccentricity e 0 024 0 014Periastron epoch T 2438 903 314 0 003 JDArgument of periastron w secondary 314 34 Semi amplitude K1 primary 43 1 0 6 km s DetailsMass9 65 8 M Radius5 5 9 R Rotational velocity v sin i 131 10 km sAge12 11 Myr Other designationsHR 4729 CPD 62 2742 GC 16951 25 G Crucis WDS J12266 6306C CCDM J12266 6306C Database referencesSIMBADdata Contents 1 Nomenclature 2 Discovery 3 System 4 Stellar properties 5 References 6 External linksNomenclature editHR 4729 is the star s designation in the Bright Star Catalogue It is also often referred to by its Henry Draper Catalogue listing of HD 108250 Because of its closeness to a Crucis it is included in many multiple star catalogues as a Crucis C 12 It is also listed as star 25 in Crux in the Uranometria Argentina displayed as 25 G Crucis 13 Discovery editHR 4729 was first observed in 1829 as a companion to a Crucis by James Dunlop from Paramatta in New South Wales 14 As early as 1916 HR 4729 was reported to have a variable radial velocity indicating a likely binary system but the orbital elements were not calculated until 1979 7 System edit nbsp a Crucis with HR 4729 close by HR 4729 lies 90 arcseconds away from the triple star system of a Crucis and shares its motion through space suggesting it may be gravitationally bound to it and it is therefore generally assumed to be physically associated In the context of being a companion to a Crucis it is usually referred to as a Crucis C 15 16 HR 4729 is itself a close spectroscopic binary system with a period of 1 day 5 hours It also has a faint visual companion 2 1 away A further seven faint stars are also listed as members of the a Crucis group out to a distance of about two arc minutes 12 One particular companion very close to HR 4729 has been resolved using adaptive optics at infrared wavelengths It has been named a Crucis P or a Crucis CP because it is only 2 from HR 4729 11 Rizzuto and colleagues determined in 2011 that the a Crucis system including HR 4729 was 66 likely to be a member of the Lower Centaurus Crux sub group of the Scorpius Centaurus association It was not previously seen to be a member of the group because of confusion over the true radial velocity of the spectroscopic pair 17 On 2008 October 2 the Cassini Huygens spacecraft resolved three of the components A B and C of the multiple star system as Saturn s disk occulted it 18 19 Stellar properties editHR 4729 is a hot class B main sequence star nearly ten times as massive as the sun It is only about twelve million years old but already shows signs of evolving away from the main sequence Several studies have assigned a subgiant luminosity class to the star 7 20 The spectroscopic companion cannot be seen in the spectrum therefore little is known about its properties Analysis of the orbit shows that it has a mass greater than the sun 8 The physically associated companion a Crucis D or a Crucis CP is a 15th magnitude star Its relative faintness suggests an M0 V spectral type 8 Two other even fainter stars lie within 10 of HR 4729 12 References edit a b Hog E Kuzmin A Bastian U Fabricius C Kuimov K Lindegren L Makarov V V Roeser S 1998 The TYCHO Reference Catalogue Astronomy and Astrophysics 335 L65 Bibcode 1998A amp A 335L 65H a b Kaltcheva N T Golev V K Moran K 2014 Massive stellar content of the Galactic supershell GSH 305 01 24 Astronomy amp Astrophysics 562 A69 arXiv 1312 5592 Bibcode 2014A amp A 562A 69K doi 10 1051 0004 6361 201321454 S2CID 54222753 Corbally C J 1984 Close visual binaries I MK classifications Astrophysical Journal Supplement Series 55 657 Bibcode 1984ApJS 55 657C doi 10 1086 190973 a b Stagg Christopher 1987 A photometric survey of the bright southern Be stars Monthly Notices of the Royal Astronomical Society 227 213 240 Bibcode 1987MNRAS 227 213S doi 10 1093 mnras 227 1 213 Wilson Ralph Elmer 1953 General Catalogue of Stellar Radial Velocities Carnegie Institute Washington D C Publication Washington Carnegie Institution of Washington Bibcode 1953GCRV C 0W a b c Brown A G A et al Gaia collaboration August 2018 Gaia Data Release 2 Summary of the contents and survey properties Astronomy amp Astrophysics 616 A1 arXiv 1804 09365 Bibcode 2018A amp A 616A 1G doi 10 1051 0004 6361 201833051 Gaia DR2 record for this source at VizieR a b c Hernandez C A De Hernandez E B 1979 The orbital elements of 25 G Crucis HD 108250 Revista Mexicana de Astronomia y Astrofisica 4 297 Bibcode 1979RMxAA 4 297H a b c Tokovinin A A 1997 MSC a catalogue of physical multiple stars Astronomy and Astrophysics Supplement Series 124 1 75 84 Bibcode 1997A amp AS 124 75T doi 10 1051 aas 1997181 ISSN 0365 0138 Wesselink A J Paranya K Devorkin K 1972 Catalogue of stellar dimensions Astronomy and Astrophysics Supplement 7 257 Bibcode 1972A amp AS 7 257W Brown A G A Verschueren W 1997 High S N Echelle spectroscopy in young stellar groups II Rotational velocities of early type stars in SCO OB2 Astronomy and Astrophysics 319 811 arXiv astro ph 9608089 Bibcode 1997A amp A 319 811B a b Tokovinin A A Chalabaev A Shatsky N I Beuzit J L 1999 A near IR adaptive optics search for faint companions to early type multiple stars Astronomy and Astrophysics 346 481 Bibcode 1999A amp A 346 481T a b c 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 Gould Benjamin Apthorp 1879 Uranometria Argentina Brillantez y posicion de las estrellas fijas hasta la septima magnitud comprendidas dentro de cien grados del polo austral Con atlas Resultados del Observatorio Nacional Argentino en Cordoba 1 Bibcode 1879RNAO 1 G Dunlop James 1829 Approximate Places of Double Stars in the Southern Hemisphere observed at Paramatta in New South Wales Memoirs of the Royal Astronomical Society 3 257 Bibcode 1829MmRAS 3 257D Shatsky N Tokovinin A 2002 The mass ratio distribution of B type visual binaries in the Sco OB2 association Astronomy and Astrophysics 382 92 103 arXiv astro ph 0109456 Bibcode 2002A amp A 382 92S doi 10 1051 0004 6361 20011542 S2CID 16697655 Eggleton Peter Tokovinin A 2008 A catalogue of multiplicity among bright stellar systems Monthly Notices of the Royal Astronomical Society 389 2 869 arXiv 0806 2878 Bibcode 2008MNRAS 389 869E doi 10 1111 j 1365 2966 2008 13596 x S2CID 14878976 Rizzuto Aaron Ireland Michael Robertson J G October 2011 Multidimensional Bayesian membership analysis of the Sco OB2 moving group Monthly Notices of the Royal Astronomical Society 416 4 3108 3117 arXiv 1106 2857 Bibcode 2011MNRAS 416 3108R doi 10 1111 j 1365 2966 2011 19256 x S2CID 54510608 NASA JPL Space Science Institute Multimedia Images Raw Images Archived 2008 10 25 at the Wayback Machine Retrieved 2008 10 21 Cassini Kodak Moments Unmanned Spaceflight com Retrieved 2008 10 21 Hiltner W A Garrison R F Schild R E 1969 MK Spectral Types for Bright Southern OB Stars Astrophysical Journal 157 313 Bibcode 1969ApJ 157 313H doi 10 1086 150069 External links edithttp www daviddarling info encyclopedia A Acrux html Retrieved from https en wikipedia org w index php title HR 4729 amp oldid 1169945329, wikipedia, wiki, book, books, library,

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