HD 177565

HD 177565

Location of HD 177565 (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Corona Australis
Right ascension	19^h 06^m 52.46439^s[1]
Declination	−37° 48′ 38.3734″[1]
Apparent magnitude (V)	6.16[2]
Characteristics
Spectral type	G6 V[3]
U−B color index	+0.27[4]
B−V color index	+0.70[4]
Astrometry
Radial velocity (Rv)	60.9±0.8[5] km/s
Proper motion (μ)	RA: −187.700 mas/yr[1] Dec.: −367.009 mas/yr[1]
Parallax (π)	58.9860 ± 0.0376 mas[1]
Distance	55.29 ± 0.04 ly (16.95 ± 0.01 pc)
Absolute magnitude (MV)	+5.00[6]
Details
Mass	0.99^+0.03 −0.04[7] M☉
Radius	0.985±0.022[8] R☉
Luminosity	0.851±0.005[1] L☉
Surface gravity (log g)	4.44±0.03[9] cgs
Temperature	5,627±19[10] K
Metallicity [Fe/H]	0.08±0.01[10] dex
Rotational velocity (v sin i)	3[11] km/s
Age	4.58±1.51[12] Gyr
Other designations
42 G. Coronae Australis[13], CD−37°13049, CPD−37°8466, GC 26283, GJ 744, HD 177565, HIP 93858, HR 7232, SAO 210937, LTT 7569[14]
Database references
SIMBAD	data

HD 177565 (HR 7232; LTT 7569; Gliese 744) is a yellow-hued star located in the southern constellation Corona Australis. It has an apparent magnitude of 6.16,[2] placing it near the limit for naked eye visibility, even under ideal conditions. The object is located relatively close at a distance of 55.3 light-years based on Gaia DR3 parallax measurements,[1] but it is receding rapidly with a heliocentric radial velocity of 60.9 km/s.[5] At its current distance, HD 177565's brightness is diminished by interstellar extinction of 0.07 magnitudes[15] and it as an absolute magnitude of +5.00.[6] A 2017 multiplicity survey failed to detect any stellar companions around the star.[16]

HD 177565 has a stellar classification of G6 V,[3] indicating that it is an ordinary G-type main-sequence star like our Sun. The object has also be given a later class of G8 V (Houk 1982)[17] and one source lists it as a G5 subgiant.[18] It has 99% the mass of the Sun[7] and 98.5% the Sun's radius.[8] It radiates 85.1% the luminosity of the Sun[1] from its photosphere at an effective temperature of 5,627 K,[10] making it slightly cooler than the Sun. HD 177565 is slightly metal enriched with an iron abundance at [Fe/H] = +0.08 (120% solar)[10] and it is estimated to be 4.58 billion years old.[12] HD 177565 spins slightly faster than the Sun with a projected rotational velocity of 3 km/s[11] compared to the Sun's rotational velocity of 2 km/s.

Planetary system

In 2017, an exoplanet was discovered orbiting the star after observations of HARPS data. HD 177565 b is a hot Neptune that takes 44.5 days to revolve around its host star in a relatively circular orbit.[19]

The HD 177565 planetary system[19]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	≥15.10^+6.40 −6.05 M🜨	0.246±0.019	44.5^+0.6 −0.3	0.059^+0.172 −0.058	—	~4.1[20] R🜨

Size comparison of the planet HD 177565 b (artistic concept) with Earth and Neptune

References

1. 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.
2. 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.
3. 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. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637. eISSN 1538-3881. ISSN 0004-6256. S2CID 250741593.
4. Cousins, A. W. J. (January 1973). "UBV Photometry of Some Southern Stars (Second List)". Monthly Notes of the Astronomical Society of South Africa. 32: 11. Bibcode:1973MNSSA..32...11C. ISSN 0024-8266.
5. Valenti, Jeff A.; Fischer, Debra A. (July 2005). "Spectroscopic Properties of Cool Stars (SPOCS). I. 1040 F, G, and K Dwarfs from Keck, Lick, and AAT Planet Search Programs". The Astrophysical Journal Supplement Series. 159 (1): 141–166. Bibcode:2005ApJS..159..141V. doi:10.1086/430500. eISSN 1538-4365. ISSN 0067-0049. S2CID 121398064.
6. 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.
7. Ramírez, I.; Fish, J. R.; Lambert, D. L.; Allende Prieto, C. (13 August 2012). "Lithium Abundances in nearby FGK Dwarf and Subgiant Stars: Internal Destruction, Galactic Chemical Evolution, and Exoplanets". The Astrophysical Journal. 756 (1): 46. arXiv:1207.0499. Bibcode:2012ApJ...756...46R. doi:10.1088/0004-637X/756/1/46. eISSN 1538-4357. ISSN 0004-637X. S2CID 119199829.
8. Masana, E.; Jordi, C.; Ribas, I. (10 April 2006). "Effective temperature scale and bolometric corrections from 2MASS photometry". Astronomy & Astrophysics. 450 (2): 735–746. arXiv:astro-ph/0601049. Bibcode:2006A&A...450..735M. doi:10.1051/0004-6361:20054021. eISSN 1432-0746. ISSN 0004-6361.
9. Aguilera-Gómez, Claudia; Ramírez, Iván; Chanamé, Julio (June 2018). "Lithium abundance patterns of late-F stars: an in-depth analysis of the lithium desert". Astronomy & Astrophysics. 614: A55. arXiv:1803.05922. Bibcode:2018A&A...614A..55A. doi:10.1051/0004-6361/201732209. eISSN 1432-0746. ISSN 0004-6361. S2CID 62799777.
10. Sousa, S. G.; Santos, N. C.; Mayor, M.; Udry, S.; Casagrande, L.; Israelian, G.; Pepe, F.; Queloz, D.; Monteiro, M. J. P. F. G. (4 June 2008). "Spectroscopic parameters for 451 stars in the HARPS GTO planet search program". Astronomy & Astrophysics. 487 (1): 373–381. arXiv:0805.4826. Bibcode:2008A&A...487..373S. doi:10.1051/0004-6361:200809698. eISSN 1432-0746. ISSN 0004-6361. S2CID 18173201.
11. Nordström, B.; Mayor, M.; Andersen, J.; Holmberg, J.; Pont, F.; Jørgensen, B. R.; Olsen, E. H.; Udry, S.; Mowlavi, N. (16 April 2004). "The Geneva-Copenhagen survey of the Solar neighbourhood". Astronomy & Astrophysics. 418 (3): 989–1019. arXiv:astro-ph/0405198. Bibcode:2004A&A...418..989N. doi:10.1051/0004-6361:20035959. eISSN 1432-0746. ISSN 0004-6361. S2CID 11027621.
12. Gomes da Silva, J.; Santos, N. C.; Adibekyan, V.; Sousa, S. G.; Campante, T. L.; Figueira, P.; Bossini, D.; Delgado-Mena, E.; Monteiro, M. J. P. F. G.; de Laverny, P.; Recio-Blanco, A.; Lovis, C. (February 2021). "Stellar chromospheric activity of 1674 FGK stars from the AMBRE-HARPS sample. I. A catalogue of homogeneous chromospheric activity". Astronomy & Astrophysics. 646: A77. arXiv:2012.10199. Bibcode:2021A&A...646A..77G. doi:10.1051/0004-6361/202039765. eISSN 1432-0746. ISSN 0004-6361. S2CID 229331727.
13. 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.
14. "HD 177565". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved June 7, 2023.
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. arXiv:1709.01160. Bibcode:2017MNRAS.472.3805G. doi:10.1093/mnras/stx2219. eISSN 1365-2966. ISSN 0035-8711. S2CID 118879856.
16. Fuhrmann, K.; Chini, R.; Kaderhandt, L.; Chen, Z. (February 14, 2017). "Multiplicity among Solar-type Stars". The Astrophysical Journal. 836 (1). American Astronomical Society: 139. Bibcode:2017ApJ...836..139F. doi:10.3847/1538-4357/836/1/139. ISSN 1538-4357. S2CID 125253901.
17. Houk, N. (1982). Michigan Catalogue of Two-dimensional Spectral Types for the HD stars. Declinations −40° to −26°. Vol. 3. Bibcode:1982mcts.book.....H.
18. Evans, D. S.; Menzies, A.; Stoy, R. H. (1 December 1959). "Fundamental Data for Southern Stars (Second List)". Monthly Notices of the Royal Astronomical Society. 119 (6): 638–647. Bibcode:1959MNRAS.119..638E. doi:10.1093/mnras/119.6.638. eISSN 1365-2966. ISSN 0035-8711.
19. Feng, F.; Tuomi, M.; Jones, H. R. A. (May 16, 2017). "Agatha: disentangling periodic signals from correlated noise in a periodogram framework". Monthly Notices of the Royal Astronomical Society. 470 (4). Oxford University Press (OUP): 4794–4814. arXiv:1705.03089. Bibcode:2017MNRAS.470.4794F. doi:10.1093/mnras/stx1126. ISSN 0035-8711. S2CID 73635720.
20. Foster, G.; Poppenhaeger, K.; Ilic, N.; Schwope, A. (2022). "Exoplanet X-ray irradiation and evaporation rates with eROSITA". Astronomy & Astrophysics. 661. EDP Sciences: A23. arXiv:2106.14550. Bibcode:2022A&A...661A..23F. doi:10.1051/0004-6361/202141097. ISSN 0004-6361.