HD 74772

HD 74772
	Location of d Velorum (circled in red)
Observation data; Epoch J2000 Equinox ICRS
Constellation	Vela
Right ascension	08h 44m 23.94539s
Declination	−42° 38′ 57.3933″
Apparent magnitude (V)	4.05
Characteristics
Spectral type	G6 III
B−V color index	0.874±0.002
Astrometry
Radial velocity (Rv)	−2.0±0.3 km/s
Proper motion (μ)	RA: −22.641 mas/yr ; Dec.: +19.137 mas/yr
Parallax (π)	15.7791±0.3148 mas
Distance	207 ± 4 ly ; (63 ± 1 pc)
Absolute magnitude (MV)	−0.18
Details
Mass	3.2 M☉
Radius	12 R☉
Luminosity	128.02 L☉
Surface gravity (log g)	2.50 cgs
Temperature	5,210 K
Metallicity [Fe/H]	−0.03 dex
Rotational velocity (v sin i)	5.8 km/s
Other designations
	d Vel, CD−42°4569, GJ 9276, HD 74772, HIP 42884, HR 3477, SAO 220371, WDS J08444-4239A
Database references
SIMBAD	data

HD 74772 (d Velorum) is a single star in the southern constellation of Vela. It is positioned near the Vela SNR, which gives it an intense X-ray background. The star is of apparent visual magnitude 4.05, and hence is visible to the naked eye. Based upon an annual parallax shift of 15.8 mas, it is located 207 light years from the Sun. It is moving closer to the Earth with a heliocentric radial velocity of −2 km/s.

This is an evolved G-type giant star with a stellar classification of G6 III. The interferometry-measured angular diameter of this star is 1.73±0.12 mas, which, at its estimated distance, equates to a physical radius of about 12 times the radius of the Sun. It has 3.2 times the mass of the Sun and is radiating 128 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 5,210 K.

References

1 2 3 4 5 6 7 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. XHIP record for this object at VizieR.
1 2 3 4 5 6 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.
1 2 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
1 2 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.
1 2 Gondoin, P. (December 1999), "Evolution of X-ray activity and rotation on G-K giants", Astronomy and Astrophysics, 352: 217–227, Bibcode:1999A&A...352..217G.
1 2 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:
$\begin{matrix} 2 \cdot R_{*} & = \frac{(1 0^{- 3} \cdot 63.4 \cdot 1.73) AU}{0.0046491 AU / R_{⨀}} \\ \approx 23.6 \cdot R_{⨀} \end{matrix}$
1 2 3 4 Jones, K. L.; et al. (June 1992), "Spectroscopic investigation of cool giants and the authenticity of their reported microwave emission", Monthly Notices of the Royal Astronomical Society, 256 (3): 535–544, Bibcode:1992MNRAS.256..535J, doi:10.1093/mnras/256.3.535.
↑ de Medeiros, J. R.; Mayor, M. (October 1995), "On the link between rotation and coronal activity in evolved stars", Astronomy and Astrophysics, 302: 745, Bibcode:1995A&A...302..745D.
↑ "HD 74772". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-08-07.
↑ Eggleton, P. P.; Tokovinin, A. 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.
↑ Maggio, A.; et al. (1993), "Soft X-ray Emission and Spectra of Evolved Stars from ROSAT Pointed Observations", in Linsky, Jeffrey L.; Serio, Salvatore (eds.), Physics of Solar and Stellar Coronae: G. S. Vaiana Memorial Symposium, held 22-26 June, 1992, in Palermo, Italy, Astrophysics and Space Science Library, vol. 183, Dordrecht, The Netherlands: Kluwer Academoc Publishers, p. 365, Bibcode:1993ASSL..183..365M, doi:10.1007/978-94-011-1964-1_47, ISBN 978-0-7923-2346-4.
↑ 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.

[Anderson2012-1] 1 2 3 4 5 6 7 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. XHIP record for this object at VizieR.

[GaiaDR2-2] 1 2 3 4 5 6 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.

[perkins1989-3] 1 2 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.

[deBruijne2012-4] 1 2 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.

[Gondoin1999-5] 1 2 Gondoin, P. (December 1999), "Evolution of X-ray activity and rotation on G-K giants", Astronomy and Astrophysics, 352: 217–227, Bibcode:1999A&A...352..217G.

[lang2006-6] 1 2 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:
$\begin{matrix} 2 \cdot R_{*} & = \frac{(1 0^{- 3} \cdot 63.4 \cdot 1.73) AU}{0.0046491 AU / R_{⨀}} \\ \approx 23.6 \cdot R_{⨀} \end{matrix}$

[Jones1992-7] 1 2 3 4 Jones, K. L.; et al. (June 1992), "Spectroscopic investigation of cool giants and the authenticity of their reported microwave emission", Monthly Notices of the Royal Astronomical Society, 256 (3): 535–544, Bibcode:1992MNRAS.256..535J, doi:10.1093/mnras/256.3.535.

[deMedeiros1995-8] Medeiros, J. R.; Mayor, M. (October 1995), "On the link between rotation and coronal activity in evolved stars", Astronomy and Astrophysics, 302: 745, Bibcode:1995A&A...302..745D.

[SIMBAD-9] "HD 74772". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-08-07.

[Eggleton2008-10] Eggleton, P. P.; Tokovinin, A. 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.

[Maggio1993-11] Maggio, A.; et al. (1993), "Soft X-ray Emission and Spectra of Evolved Stars from ROSAT Pointed Observations", in Linsky, Jeffrey L.; Serio, Salvatore (eds.), Physics of Solar and Stellar Coronae: G. S. Vaiana Memorial Symposium, held 22-26 June, 1992, in Palermo, Italy, Astrophysics and Space Science Library, vol. 183, Dordrecht, The Netherlands: Kluwer Academoc Publishers, p. 365, Bibcode:1993ASSL..183..365M, doi:10.1007/978-94-011-1964-1_47, ISBN 978-0-7923-2346-4.

[Richichi2005-12] 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.