Astronomy:HD 190422

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Short description: F-type main-sequence star; Telescopium
HD 190422
Telescopium constellation map.svg
Red circle.svg
Location of HD 190422(circled)
Observation data
Epoch J2000.0   Equinox (celestial coordinates)
Constellation Telescopium
Right ascension  20h 07m 35.09061s[1]
Declination −55° 00′ 57.6492″[1]
Apparent magnitude (V) 6.25±0.01[2]
Characteristics
Spectral type F9 V CH−0.4[3]
B−V color index +0.53[4]
Astrometry
Radial velocity (Rv)12.7±0.3[5] km/s
Proper motion (μ) RA: +18.283[1] mas/yr
Dec.: +35.310[1] mas/yr
Parallax (π)41.5069 ± 0.028[1] mas
Distance78.58 ± 0.05 ly
(24.09 ± 0.02 pc)
Absolute magnitude (MV)+4.41[6]
Details
Mass1.25[7] M
Radius1.09±0.05[8] R
Luminosity1.534+0.006−0.005[1] L
Surface gravity (log g)4.42[3] cgs
Temperature6,235±100[9] K
Metallicity [Fe/H]−0.13±0.03[10] dex
Rotation27.2 d[11]
Rotational velocity (v sin i)15.6±0.8[12] km/s
Age400[13][3] Myr
Other designations
CD−55°8393, CPD−55°9317, GC 27884, HD 190422, HIP 99137, HR 7674, SAO 246444[14]
Database references
SIMBADdata

HD 190422, also known as HR 7674 or rarely 77 G. Telescopii, is a solitary star located in the southern constellation Telescopium. It has an apparent magnitude of +6.25,[2] placing it near the limit for naked eye, even under ideal conditions. At its current distance, HD 190422's brightness is diminished by 0.11 magnitudes due to extinction from interstellar dust[15] and it has an absolute magnitude of +4.41.[6]

The star is located relatively close at a distance of 79 light years based on Gaia DR3 parallax measurements[1] but it is receding with a heliocentric radial velocity of 12.7 km/s.[5] Approximately 1.6 million years ago, HD 190422 was located 7.806 parsecs (25.46 ly) away from the Sun.[16]

HD 190422 has a stellar classification of F9 V CH−0.4,[3] indicating that it is a F-type main-sequence star with a mild underabundance of the CH radical in its spectrum. It has 125% the mass of the Sun[7] and 109% of the Sun's radius.[8] It radiates 1.534 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 6,235 K,[9] giving it a whitish-yellow hue. HD 190422 is slightly metal deficient with a metallicity of [Fe/H] = −0.13[10] and it spins modestly with a projected rotational velocity of 15.6 km/s.[12] The star is estimated to be 400 million years old,[13][3] less than a tenth the age of the Sun.

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 3.2 3.3 3.4 Gray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Bubar, E. J.; McGahee, C. E.; O'Donoghue, A. A.; Knox, E. R. (2 June 2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc--The Southern Sample". The Astronomical Journal 132 (1): 161–170. doi:10.1086/504637. ISSN 0004-6256. Bibcode2006AJ....132..161G. 
  4. 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. Bibcode1966CoLPL...4...99J. 
  5. 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. Bibcode2006AstL...32..759G. 
  6. 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. Bibcode2012AstL...38..331A. 
  7. 7.0 7.1 Chandler, Colin Orion; McDonald, Iain; Kane, Stephen R. (17 February 2016). "The Catalog of Earth-Like Exoplanet Survey Targets (CELESTA): A Database of Habitable Zones Around Nearby Stars". The Astronomical Journal 151 (3): 59. doi:10.3847/0004-6256/151/3/59. Bibcode2016AJ....151...59C. 
  8. 8.0 8.1 Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (October 2004). "The angular sizes of dwarf stars and subgiants. Surface brightness relations calibrated by interferometry". Astronomy & Astrophysics 426 (1): 297–307. doi:10.1051/0004-6361:20035930. ISSN 0004-6361. Bibcode2004A&A...426..297K. 
  9. 9.0 9.1 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. Oelkers, Ryan J.; Rodriguez, Joseph E.; Stassun, Keivan G.; Pepper, Joshua; Somers, Garrett; Kafka, Stella; Stevens, Daniel J.; Beatty, Thomas G. et al. (2018). "Variability Properties of Four Million Sources in the TESS Input Catalog Observed with the Kilodegree Extremely Little Telescope Survey". The Astronomical Journal 155 (1): 39. doi:10.3847/1538-3881/aa9bf4. Bibcode2018AJ....155...39O. 
  12. 12.0 12.1 Ammler-von Eiff, M.; Reiners, A. (June 2012). "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?". Astronomy & Astrophysics 542: A116. doi:10.1051/0004-6361/201118724. ISSN 0004-6361. Bibcode2012A&A...542A.116A. 
  13. 13.0 13.1 Henry, Todd J.; Soderblom, David R.; Donahue, Robert A.; Baliunas, Sallie L. (January 1996). "A Survey of CA II H and K Chromospheric Emission in Southern Solar-Type Stars". The Astronomical Journal 111: 439. doi:10.1086/117796. ISSN 0004-6256. Bibcode1996AJ....111..439H. 
  14. "HD 190422". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+190422. 
  15. 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. 
  16. Bailer-Jones, C. A. L. (19 February 2015). "Close encounters of the stellar kind". Astronomy & Astrophysics 575: A35. doi:10.1051/0004-6361/201425221. ISSN 0004-6361. Bibcode2015A&A...575A..35B. 
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