Astronomy:HD 181295

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Short description: Astrometric binary in the constellation Telescopium.
HD 181295
Observation data
Epoch J2000.0   Equinox (celestial coordinates)
Constellation Telescopium
Right ascension  19h 22m 37.74947s[1]
Declination −51° 13′ 52.6099″[1]
Apparent magnitude (V) 6.42±0.01[2]
Characteristics
Evolutionary stage main sequence star[3]
Spectral type F0 V[4]
B−V color index 0.328±0.007[5]
Astrometry
Radial velocity (Rv)−35.7±0.5[6] km/s
Proper motion (μ) RA: 73.087[1] mas/yr
Dec.: −8.778[1] mas/yr
Parallax (π)12.9643 ± 0.4818[1] mas
Distance252 ± 9 ly
(77 ± 3 pc)
Absolute magnitude (MV)+2.14[5]
Details
Mass1.74[7] M
Radius2.35±0.15[8] R
Luminosity13.3+0.9−0.8[1] L
Surface gravity (log g)3.84[9] cgs
Temperature6,850±69[8] K
Metallicity [Fe/H]−0.27[10] dex
Rotation2.7 d[11]
Rotational velocity (v sin i)56.9±1.9[11] km/s
Age1.41[7] Gyr
Other designations
CD−51°12054, CPD−51°11215, GC 22691, HD 181295, HIP 95239, SAO 246053[12]
Database references
SIMBADdata

HD 181295 is a star located in the southern constellation Telescopium. It has an apparent magnitude of 6.42,[2] placing it near the limit of naked eye visibility, even under ideal conditions. The object is located relatively close at a distance of approximately 252 light-years based on Gaia DR3 parallax measurements,[1] and it is currently drifting closer with a heliocentric radial velocity of −35.7 km/s.[6] At its current distance, HD 181295's brightness is diminished by 0.22 magnitudes[13] due to interstellar extinction and it has an absolute magnitude +2.14.[5]

Proper motion variations from this star was first detected in a 2005 Hipparcos proper motion survey.[14] These variations indicated the presence of an unseen companion tugging on the star. As of the follow up survey published in 2006, it is considered a probable astrometric binary with a 97% chance.[15]

The visible component has a stellar classification of F0 V,[4] indicating that it is an ordinary F-type main-sequence star that is generating energy via hydrogen fusion at its core. It has 1.74 times the mass of the Sun[7] and 2.35 times the radius of the Sun.[8] It radiates 13.3 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 6,850 K,[8] giving it the typical yellowish-white of a F-type star. At the age of 1.41 billion years,[7] HD 181295A is a rather evolved star for its class, having completed 77.3% of its main sequence lifetime.[3] The star has an iron abundance of [Fe/H] = −0.27[10] and it spins modestly with a projected rotational velocity of 56.9 km/s within 2.7 days.[11]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 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. 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. Bibcode2000A&A...355L..27H. 
  3. 3.0 3.1 Zorec, J.; Royer, F. (January 2012). "Rotational velocities of A-type stars IV: Evolution of rotational velocities". Astronomy & Astrophysics 537: A120. doi:10.1051/0004-6361/201117691. ISSN 0004-6361. Bibcode2012A&A...537A.120Z. 
  4. 4.0 4.1 Houk, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars: Declinations −90° to −53°. 1. Bibcode1975mcts.book.....H. 
  5. 5.0 5.1 5.2 Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331–346. doi:10.1134/S1063773712050015. ISSN 1063-7737. Bibcode2012AstL...38..331A. 
  6. 6.0 6.1 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. Bibcode2006AstL...32..759G. 
  7. 7.0 7.1 7.2 7.3 David, Trevor J.; Hillenbrand, Lynne A. (12 May 2015). "The Ages of Early-type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal 804 (2): 146. doi:10.1088/0004-637X/804/2/146. Bibcode2015ApJ...804..146D. 
  8. 8.0 8.1 8.2 8.3 Masana, E.; Jordi, C.; Ribas, I. (10 April 2006). "Effective temperature scale and bolometric corrections from 2MASS photometry". Astronomy & Astrophysics 450 (2): 735–746. doi:10.1051/0004-6361:20054021. ISSN 0004-6361. Bibcode2006A&A...450..735M. 
  9. Casagrande, L.; Schönrich, R.; Asplund, M.; Cassisi, S.; Ramírez, I.; Meléndez, J.; Bensby, T.; Feltzing, S. (26 May 2011). "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s): Improved astrophysical parameters for the Geneva-Copenhagen Survey⋆". Astronomy & Astrophysics 530: A138. doi:10.1051/0004-6361/201016276. ISSN 0004-6361. Bibcode2011A&A...530A.138C. 
  10. 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. Bibcode2017MNRAS.469.3042N. 
  11. 11.0 11.1 11.2 Reiners, A.; Royer, F. (February 2004). "First signatures of strong differential rotation in A-type stars". Astronomy & Astrophysics 415 (1): 325–329. doi:10.1051/0004-6361:20034175. ISSN 0004-6361. Bibcode2004A&A...415..325R. 
  12. "HD 181295". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+181295. 
  13. 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. Bibcode2017MNRAS.472.3805G. 
  14. Makarov, V. V.; Kaplan, G. H. (May 2005). "Statistical Constraints for Astrometric Binaries with Nonlinear Motion". The Astronomical Journal 129 (5): 2420–2427. doi:10.1086/429590. ISSN 0004-6256. Bibcode2005AJ....129.2420M. 
  15. Frankowski, A.; Jancart, S.; Jorissen, A. (19 December 2006). "Proper-motion binaries in the Hipparcos catalogue: Comparison with radial velocity data". Astronomy & Astrophysics 464 (1): 377–392. doi:10.1051/0004-6361:20065526. ISSN 0004-6361. Bibcode2007A&A...464..377F. 
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