Astronomy:HD 194688
Location of HD 194688 on the map (circled) | |
| Observation data Epoch J2000.0 Equinox (celestial coordinates) | |
|---|---|
| Constellation | Delphinus |
| Right ascension | 20h 26m 23.15478s[1] |
| Declination | +17° 18′ 56.0140″[1] |
| Apparent magnitude (V) | 6.22±0.01[2] |
| Characteristics | |
| Spectral type | K0[3] |
| B−V color index | +1.01[4] |
| Astrometry | |
| Radial velocity (Rv) | −17.12±0.27[5] km/s |
| Proper motion (μ) | RA: +5.397[1] mas/yr Dec.: −5.426[1] mas/yr |
| Parallax (π) | 3.6827 ± 0.0184[1] mas |
| Distance | 886 ± 4 ly (272 ± 1 pc) |
| Absolute magnitude (MV) | −1.19[6] |
| Details | |
| Mass | 1.57[7] M☉ |
| Radius | 21.58[8] R☉ |
| Luminosity | 258+3−2[1] L☉ |
| Surface gravity (log g) | 1.91[7] cgs |
| Temperature | 4,995±122[9] K |
| Metallicity [Fe/H] | −0.13[7] dex |
| Other designations | |
| 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,[2] 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,[1] but it is drifting closer with a heliocentric radial velocity of −17.12 km/s.[5] At its current distance, HD 196488's brightness is diminished due to an interstellar extinction of 0.17 magnitudes[11] and it has an absolute visual magnitude of −1.19.[6]
HD 194688 has a simple stellar classification of K0,[3] indicating that it is an early K-type star. It has 1.57 times the mass of the Sun[7] and an enlarged radius 21.58 times that of the Sun.[8] It radiates 258 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 4,995 K,[9] 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.[7]
References
- ↑ 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.
- ↑ 2.0 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. Bibcode: 2000A&A...355L..27H.
- ↑ 3.0 3.1 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.
- ↑ Haggkvist, L.; Oja, T. (1970). "Results of BV photometry 1969-70 (Uppsala refractor)". Private Communication. Bibcode: 1970Priv.........0H.
- ↑ 5.0 5.1 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. doi:10.1051/0004-6361:20041272. Bibcode: 2005A&A...430..165F.
- ↑ 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. Bibcode: 2012AstL...38..331A.
- ↑ 7.0 7.1 7.2 7.3 7.4 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. doi:10.1051/0004-6361/201935765. ISSN 0004-6361. Bibcode: 2019A&A...628A..94A.
- ↑ 8.0 8.1 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. doi:10.1093/mnras/stx1433. ISSN 0035-8711. Bibcode: 2017MNRAS.471..770M.
- ↑ 9.0 9.1 Stassun, Keivan G. et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. Bibcode: 2019AJ....158..138S.
- ↑ "HD 198404". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+198404.
- ↑ 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. Bibcode: 2017MNRAS.472.3805G.
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