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HD 194688

Location of HD 194688 on the map (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Delphinus
Right ascension	20 26 23.15478
Declination	+17° 18′ 56.0140″
Apparent magnitude (V)	6.22±0.01
Characteristics
Spectral type	K0
B−V color index	+1.01
Astrometry
Radial velocity (Rv)	−17.12±0.27 km/s
Proper motion (μ)	RA: +5.397 mas/yr Dec.: −5.426 mas/yr
Parallax (π)	3.6827 ± 0.0184 mas
Distance	886 ± 4 ly (272 ± 1 pc)
Absolute magnitude (MV)	−1.19
Details
Mass	1.57 M☉
Radius	21.58 R☉
Luminosity	258 −2 L☉
Surface gravity (log g)	1.91 cgs
Temperature	4,995±122 K
Metallicity	−0.13 dex
Other designations
AG+17°2201, BD+16°4259, FK5 3635, GC 28435, HD 194688, HIP 100807, HR 7816, SAO 106101, TIC 305526917
Database references
SIMBAD	data

HD 194688, also designated as HR 7816, is a solitary star located in the northern constellation Delphinus, the dolphin. It has an apparent magnitude of 6.22, placing it near the limit for naked eye visibility. The object is located relatively far away at a distance of 886 light-years based on Gaia DR3 parallax measurements, but it is drifting closer with a heliocentric radial velocity of −17.12 km/s. At its current distance, HD 196488's brightness is diminished due to an interstellar extinction of 0.17 magnitudes and it has an absolute visual magnitude of −1.19.

HD 194688 has a simple stellar classification of K0, indicating that it is an early K-type star. It has 1.57 times the mass of the Sun and an enlarged radius 21.58 times that of the Sun. It radiates 258 times the luminosity of the Sun from its photosphere at an effective temperature of 4,995 K, giving it an orangish-yellow hue when viewed in the night sky. The large radius and high luminosity suggests that HD 194688 may be an evolved giant star. It is slightly metal-deficient with an iron abundance 74.1% that of the Sun's.

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. ^ 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. S2CID 17128864.
3. ^ Cannon, Annie Jump; Pickering, Edward Charles (1923). "The Henry Draper catalogue : 19h and 20h". Annals of Harvard College Observatory. 98: 1. Bibcode:1923AnHar..98....1C.
4. Haggkvist, L.; Oja, T. (1970). "Results of BV photometry 1969-70 (Uppsala refractor)". Private Communication. Bibcode:1970Priv.........0H. S2CID 231475662.
5. ^ Famaey, B.; Jorissen, A.; Luri, X.; Mayor, M.; Udry, S.; Dejonghe, H.; Turon, C. (January 2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters". Astronomy and Astrophysics. 430: 165. arXiv:astro-ph/0409579. Bibcode:2005A&A...430..165F. doi:10.1051/0004-6361:20041272. S2CID 17804304.
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. ^ Anders, F.; et al. (August 2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy & Astrophysics. 628: A94. arXiv:1904.11302. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765. eISSN 1432-0746. ISSN 0004-6361. S2CID 131780028.
8. ^ McDonald, I.; Zijlstra, A. A.; Watson, R. A. (15 June 2017). "Fundamental parameters and infrared excesses of Tycho–Gaia stars". Monthly Notices of the Royal Astronomical Society. 471 (1): 770–791. arXiv:1706.02208. Bibcode:2017MNRAS.471..770M. doi:10.1093/mnras/stx1433. eISSN 1365-2966. ISSN 0035-8711. S2CID 73594365.
9. ^ 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.
10. "HD 198404". SIMBAD. Centre de données astronomiques de Strasbourg.
11. 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.

v t e Constellation of Delphinus
List of stars in Delphinus Delphinus in Chinese astronomy
Stars	Bayer α (Sualocin) β (Rotanev) γ γ δ ε (Aldulfin) ζ η θ ι κ ρ Aql (Tso Ke) Flamsteed 1 10 13 14 15 16 17 18 (Musica) Variable EU HR HU V339 QV Sge HR 7771 7774 7778 7793 7816 7824 7839 7899 7907 7975 8010 8044 HD 195019 Other HAT-P-23 (Moriah) WASP-2 WISE J2030+0749 WISE 2056+1459
Exoplanets 18 Delphini b HD 195019 b HD 196885 Ab WASP-2b TOI-6883 b
Star clusters Laevens 3 NGC 6934 NGC 7006
Nebulae NGC 6905
Galaxies	NGC 7003 7025 7028 Other ZW II 96
Category

• K-type giants
• Delphinus
• Durchmusterung objects
• Henry Draper Catalogue objects
• Hipparcos objects
• Bright Star Catalogue objects
• TIC objects