HD 101782, also known as HR 4507, is a yellowish-orange hued star located in the southern circumpolar constellation of Chamaeleon. It has an apparent magnitude of 6.33,[2] placing it near the limit for naked eye visibility. Based on parallax measurements from Gaia DR3, the object is estimated to be 356 light years away from the Solar System.[1] It appears to be receding with a heliocentric radial velocity of 11.5 km/s.[6] De Mederios found the radial velocity to be variable, suggesting that it may be a spectroscopic binary.[12] Eggen (1989) lists it as a member of the young disk population.[11]
  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Chamaeleon |
| Right ascension | 11h 41m 01.30826s[1] |
| Declination | −83° 05′ 59.7773″[1] |
| Apparent magnitude (V) | 6.33±0.01[2] |
| Characteristics | |
| Evolutionary stage | horizontal branch[3] |
| Spectral type | K0 III[4] |
| U−B color index | +0.88[5] |
| B−V color index | +1.08[5] |
| Astrometry | |
| Radial velocity (Rv) | 11.5±0.4[6] km/s |
| Proper motion (μ) | RA: −59.825 mas/yr[1] Dec.: +9.477 mas/yr[1] |
| Parallax (π) | 9.1605 ± 0.0172 mas[1] |
| Distance | 356.0 ± 0.7 ly (109.2 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.11[7] |
| Details | |
| Mass | 2±0.5[8] M☉ |
| Radius | 10.1[9] R☉ |
| Luminosity | 55.25±0.21[1] L☉ |
| Surface gravity (log g) | 2.73[1] cgs |
| Temperature | 4,663±127[10] K |
| Metallicity [Fe/H] | +0.04[11] dex |
| Rotational velocity (v sin i) | <1.1[12] km/s |
| Age | 455[1] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 101782 has a stellar classification of K0 III,[4] indicating that it is an evolved red giant. It is currently on the horizontal branch (HB), fusing helium at its core.[3] The star is located on the cool end of the red clump, a region on the HR diagram with metal-rich HB stars. It has double the mass of the Sun[8] but has expanded to 10.1 times its girth.[9] It radiates 55 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 4,663 K.[10] It has an iron abundance 110% that of the Sun's, placing it at solar metallicity.[11] Like most giants it spins slowly, having a projected rotational velocity lower than 1.1 km/s.[12]
TYC 9507-3649-1 is a 10th magnitude optical companion located 25.9″ away along a position angle of 139°.[15] This companion was first noticed by Sir John Herschel in 1837.[16]
References
edit- ^ a b c d e f g h i 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 Laney, C. D.; Joner, M. D.; Pietrzyński, G. (11 November 2011). "A new Large Magellanic Cloud K-band distance from precision measurements of nearby red clump stars". Monthly Notices of the Royal Astronomical Society. 419 (2): 1637–1641. arXiv:1109.4800. Bibcode:2012MNRAS.419.1637L. doi:10.1111/j.1365-2966.2011.19826.x. ISSN 0035-8711.
- ^ a b 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.
- ^ 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.
- ^ 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 Charbonnel, C.; Lagarde, N.; Jasniewicz, G.; North, P. L.; Shetrone, M.; Krugler Hollek, J.; Smith, V. V.; Smiljanic, R.; Palacios, A.; Ottoni, G. (January 2020). "Lithium in red giant stars: Constraining non-standard mixing with large surveys in the Gaia era". Astronomy & Astrophysics. 633: A34. arXiv:1910.12732. Bibcode:2020A&A...633A..34C. doi:10.1051/0004-6361/201936360. eISSN 1432-0746. ISSN 0004-6361.
- ^ a b 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.
- ^ a b Bai, Yu; Liu, JiFeng; Bai, ZhongRui; Wang, Song; Fan, DongWei (2 August 2019). "Machine-learning Regression of Stellar Effective Temperatures in the Second Gaia Data Release". The Astronomical Journal. 158 (2): 93. arXiv:1906.09695. Bibcode:2019AJ....158...93B. doi:10.3847/1538-3881/ab3048. eISSN 1538-3881.
- ^ a b c Eggen, Olin J. (January 1989). "Large and Kinematically Unbiased Samples of G- and K-Type Stars. III. Evolved Young Disk Stars in the Bright Star Sample". Publications of the Astronomical Society of the Pacific. 101: 54. Bibcode:1989PASP..101...54E. doi:10.1086/132404. eISSN 1538-3873. ISSN 0004-6280.
- ^ a b c De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (January 2014). "A catalog of rotational and radial velocities for evolved stars". Astronomy & Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. eISSN 1432-0746. ISSN 0004-6361.
- ^ 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 101782". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved October 9, 2022.
- ^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. ISSN 0004-6256.
- ^ Herschel, J. F. W. (1835). "A Second Series of Micrometrical Measures of Double Stars chiefly performed with the 7-feet Equatorial, at Slough, in the years 1831, 1832, and 1833". Memoirs of the Royal Astronomical Society. 8: 37. Bibcode:1835MmRAS...8...37H.