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.[14] It has an absolute magnitude of +2.08.[6]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| 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 mas/yr[1] Dec.: −8.231 mas/yr[1] |
| Parallax (π) | 13.3992 ± 0.0202 mas[1] |
| 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 |
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,[15] 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
edit- ^ a b c d e f g h Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361.
- ^ a b Oblak, E.; Chareton, M. (September 1981). "On the Estimation of Photometric Spectral Types". Astronomy and Astrophysics Supplement Series. 45: 459. Bibcode:1981A&AS...45..459O. ISSN 0365-0138.
- ^ a b 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.
- ^ a b 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. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. eISSN 1562-6873. ISSN 1063-7737. S2CID 119231169.
- ^ a b Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. eISSN 1562-6873. ISSN 1063-7737. S2CID 119257644.
- ^ a b 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. arXiv:astro-ph/9911002. Bibcode:1999A&A...352..555A. ISSN 0004-6361.
- ^ a b 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. arXiv:astro-ph/0404180. Bibcode:2004A&A...426..297K. doi:10.1051/0004-6361:20035930. eISSN 1432-0746. ISSN 0004-6361.
- ^ a b c Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. eISSN 1538-3881. hdl:1721.1/124721. S2CID 166227927.
- ^ a b 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. arXiv:1705.00883. Bibcode:2017MNRAS.469.3042N. doi:10.1093/mnras/stx1077. eISSN 1365-2966. ISSN 0035-8711.
- ^ a b Gontcharov, G. A. (December 2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters. 38 (12): 771–782. arXiv:1606.08814. Bibcode:2012AstL...38..771G. doi:10.1134/S1063773712120031. eISSN 1562-6873. ISSN 1063-7737.
- ^ Gould, Benjamin Apthorp (1878). "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. 1. Bibcode:1879RNAO....1.....G.
- ^ "HD 99015". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved January 30, 2023.
- ^ 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. arXiv:1709.01160. Bibcode:2017MNRAS.472.3805G. doi:10.1093/mnras/stx2219. eISSN 1365-2966. ISSN 0035-8711.
- ^ 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.