Astronomy:HD 99015
Observation data Epoch J2000.0 Equinox (celestial coordinates) | |
---|---|
Constellation | Chamaeleon |
Right ascension | 11h 21m 56.89166s[1] |
Declination | −77° 36′ 30.1275″[1] |
Apparent magnitude (V) | 6.42±0.01[2] |
Characteristics | |
Evolutionary stage | main sequence[1] |
Spectral type | A5 V[3] |
U−B color index | +0.11[4] |
B−V color index | +0.20[4] |
Astrometry | |
Radial velocity (Rv) | −5.9±2.5[5] km/s |
Proper motion (μ) | RA: −79.623[1] mas/yr Dec.: −8.231[1] mas/yr |
Parallax (π) | 13.3992 ± 0.0202[1] mas |
Distance | 243.4 ± 0.4 ly (74.6 ± 0.1 pc) |
Absolute magnitude (MV) | +2.08[6] |
Details | |
Mass | 1.87±0.06[7] M☉ |
Radius | 1.83±0.09[8] R☉ |
Luminosity | 12.0+0.3−0.2[1] L☉ |
Surface gravity (log g) | 4.2±0.1[9] cgs |
Temperature | 7,859±124[9] K |
Metallicity [Fe/H] | +0.15[10] dex |
Age | 854[11] Myr |
Other designations | |
Database references | |
SIMBAD | data |
HD 99015, also known as HR 4397 or rarely 31 G. Chamaeleontis, is a solitary white-hued star located in the southern circumpolar constellation Chamaeleon. It has an apparent magnitude of 6.42,[2] placing it near the limit for naked eye visibility even in ideal conditions. The object is located relatively close at a distance of 243 light years[1] and is drifting closer with a somewhat constrained heliocentric radial velocity of −5.9 km/s.[5] At its current distance, HD 99015's brightness is diminished by 0.31 magnitudes due to interstellar dust.[13] It has an absolute magnitude of +2.08.[6]
This is an ordinary A-type main-sequence star with a stellar classification of A5 V.[3] However, Nancy Houk and A. P. Cowley gave a class of A5 III/IV,[14] indicating that it is instead an evolved A-type star with the luminosity class of a subgiant and giant star. It has 1.87 times the mass of the Sun[7] and 1.83 times the solar radius.[8] It radiates 12 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 7,859 K.[9] HD 99015 is somewhat metal enriched ([Fe/H] = +0.15[10]) and is estimated to be 854 million years old.[11]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P. et al. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. ISSN 0004-6361. Bibcode: 2000A&A...355L..27H.
- ↑ 3.0 3.1 Oblak, E.; Chareton, M. (September 1981). "On the Estimation of Photometric Spectral Types". Astronomy and Astrophysics Supplement Series 45: 459. ISSN 0365-0138. Bibcode: 1981A&AS...45..459O.
- ↑ 4.0 4.1 Johnson, H. L.; Mitchell, R. I.; Iriarte, B.; Wisniewski, W. Z. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory 4: 99–110. Bibcode: 1966CoLPL...4...99J.
- ↑ 5.0 5.1 Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35,495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. ISSN 1063-7737. Bibcode: 2006AstL...32..759G.
- ↑ 6.0 6.1 Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331–346. doi:10.1134/S1063773712050015. ISSN 1063-7737. Bibcode: 2012AstL...38..331A.
- ↑ 7.0 7.1 Allende Prieto, C.; Lambert, D. L. (December 1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures". Astronomy and Astrophysics 352: 555–562. ISSN 0004-6361. Bibcode: 1999A&A...352..555A.
- ↑ 8.0 8.1 Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (October 2004). "The angular sizes of dwarf stars and subgiants". Astronomy & Astrophysics 426 (1): 297–307. doi:10.1051/0004-6361:20035930. ISSN 0004-6361. Bibcode: 2004A&A...426..297K.
- ↑ 9.0 9.1 9.2 Stassun, Keivan G. et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. Bibcode: 2019AJ....158..138S.
- ↑ 10.0 10.1 Netopil, Martin (4 May 2017). "Metallicity calibrations for dwarf stars and giants in the Geneva photometric system". Monthly Notices of the Royal Astronomical Society 469 (3): 3042–3055. doi:10.1093/mnras/stx1077. ISSN 0035-8711. Bibcode: 2017MNRAS.469.3042N.
- ↑ 11.0 11.1 Gontcharov, G. A. (December 2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters 38 (12): 771–782. doi:10.1134/S1063773712120031. ISSN 1063-7737. Bibcode: 2012AstL...38..771G.
- ↑ "HD 99015". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+99015.
- ↑ Gontcharov, George A.; Mosenkov, Aleksandr V. (28 September 2017). "Verifying reddening and extinction for Gaia DR1 TGAS main sequence stars". Monthly Notices of the Royal Astronomical Society 472 (4): 3805–3820. doi:10.1093/mnras/stx2219. ISSN 0035-8711. Bibcode: 2017MNRAS.472.3805G.
- ↑ Houk, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars. Volume I. Declinations −90° to −53°. Bibcode: 1975mcts.book.....H.
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Original source: https://en.wikipedia.org/wiki/HD 99015.
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