KELT-1 is a F-type main-sequence star. Its surface temperature is 6518±50 K. It is similar to the Sun in its concentration of heavy elements, with a metallicity Fe/H index of 0.008±0.073, but is much younger at an age of 1.75±0.25 billion years. The star is rotating very rapidly.[2]

KELT-1
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension 00h 01m 26.9169s[1]
Declination 39° 23′ 01.7821″[1]
Apparent magnitude (V) 10.63
Characteristics
Evolutionary stage main-sequence star
Spectral type F[2]
Astrometry
Radial velocity (Rv)1.296[3] km/s
Proper motion (μ) RA: -9.696[3] mas/yr
Dec.: -7.823[3] mas/yr
Parallax (π)3.6836 ± 0.0144 mas[3]
Distance885 ± 3 ly
(271 ± 1 pc)
Position (relative to KELT-1)[2]
ComponentKELT-1B
Epoch of observation2012
Angular distance0.588±0.001
Position angle157.4±0.2°
Projected separation154±8 AU
Details[2]
Mass1.324±0.026 M
Radius1.462+0.037
−0.024
 R
Luminosity3.11±0.05[4] L
Surface gravity (log g)4.229+0.012
−0.019
 cgs
Temperature6518±50 K
Metallicity [Fe/H]0.008±0.073 dex
Rotational velocity (v sin i)55 km/s
Age1.75±0.25 Gyr
Other designations
TOI-1476, TYC 2785-2130-1, GSC 02785-02130, 2MASS J00012691+3923017[1]
Database references
SIMBADdata

A red dwarf stellar companion at a projected separation of 154±8 AU was detected in 2012, simultaneously with a planetary companion.[2]

Planetary system

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The star was found to be orbited by a low-mass brown dwarf or giant planet in 2012.[2]

The atmosphere of the brown dwarf KELT-1b has been extensively measured from space- and ground-based observatories by a team of astronomers led by Thomas Beatty. They found that KELT-1b has an equilibrium temperature of 2422+32
−26
K,[2] but features a very strong contrast between measured dayside and nightside temperatures. Dayside temperature appears to be 3340±110 K,[5] while nightside temperature is 1173+175
−130
K.[6] The excess dayside temperature may be an artifact arising from highly reflective (dayside albedo reaching 0.5, which is unusual for hot planets and brown dwarfs) rock-vapor clouds. Also, the brightest band is shifted eastward from the subsolar point by 18.3±7.4°.[5]

KELT-1b's density of 22.1+5.62
−9.16
g/cm3 is the highest among well characterized planets.[4]

The planetary orbit is well aligned with the equatorial plane of the star, with the misalignment angle equal to 2±16°.[2] Despite the short orbital period, orbital decay of KELT-1b has not been detected as of 2018.[7]

The KELT-1 planetary system[7][4]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b 27.23+0.50
−0.48
 MJ
0.02466±0.00016 1.21749397 0 85.3+2.9
−2.6
°
1.15+0.10
−0.15
 RJ

See also

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References

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  1. ^ a b c "KELT-1". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-01-18.
  2. ^ a b c d e f g h Siverd, Robert J.; Beatty, Thomas G.; Pepper, Joshua; Eastman, Jason D.; Collins, Karen; Bieryla, Allyson; Latham, David W.; Buchhave, Lars A.; Jensen, Eric L. N.; Crepp, Justin R.; Street, Rachel; Stassun, Keivan G.; Scott Gaudi, B.; Berlind, Perry; Calkins, Michael L.; Depoy, D. L.; Esquerdo, Gilbert A.; Fulton, Benjamin J.; Fűrész, Gábor; Geary, John C.; Gould, Andrew; Hebb, Leslie; Kielkopf, John F.; Marshall, Jennifer L.; Pogge, Richard; Stanek, K. Z.; Stefanik, Robert P.; Szentgyorgyi, Andrew H.; Trueblood, Mark; et al. (2012), "KELT-1b: A STRONGLY IRRADIATED, HIGHLY INFLATED, SHORT PERIOD, 27 JUPITER-MASS COMPANION TRANSITING A MID-F STAR", The Astrophysical Journal, 761 (2): 123, arXiv:1206.1635, Bibcode:2012ApJ...761..123S, doi:10.1088/0004-637X/761/2/123, S2CID 118439102
  3. ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  4. ^ a b c Johns, Daniel; Marti, Connor; Huff, Madison; McCann, Jacob; Wittenmyer, Robert A.; Horner, Jonathan; Wright, Duncan J. (2018), "Revised Exoplanet Radii and Habitability Using Gaia Data Release 2", The Astrophysical Journal Supplement Series, 239 (1): 14, arXiv:1808.04533, Bibcode:2018ApJS..239...14J, doi:10.3847/1538-4365/aae5fb, S2CID 119503072
  5. ^ a b Beatty, Thomas G.; Wong, Ian; Fetherolf, Tara; Line, Michael R.; Shporer, Avi; Stassun, Keivan G.; Ricker, George R.; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; Louie, Dana R.; Schlieder, Joshua E.; Sha, Lizhou; Tenenbaum, Peter; Yahalomi, Daniel A. (2020), "The TESS phase curve of KELT-1b suggests a high dayside albedo", The Astronomical Journal, 160 (5): 211, arXiv:2006.10292, Bibcode:2020AJ....160..211B, doi:10.3847/1538-3881/abb5aa, S2CID 219792029
  6. ^ Beatty, Thomas G.; Marley, Mark S.; Gaudi, B. Scott; Colón, Knicole D.; Fortney, Jonathan J.; Showman, Adam P. (2019), "Spitzer Phase Curves of KELT-1b and the Signatures of Nightside Clouds in Thermal Phase Observations", The Astronomical Journal, 158 (4): 166, arXiv:1808.09575, Bibcode:2019AJ....158..166B, doi:10.3847/1538-3881/ab33fc, S2CID 119055976
  7. ^ a b Maciejewski, G.; Fernández, M.; Aceituno, F.; Martín-Ruiz, S.; Ohlert, J.; Dimitrov, D.; Szyszka, K.; von Essen, C.; Mugrauer, M.; Bischoff, R.; Michel, K. -U.; Mallonn, M.; Stangret, M.; Moździerski, D. (2018), "Planet-star interactions with precise transit timing. I. The refined orbital decay rate for WASP-12 b and initial constraints for HAT-P-23 b, KELT-1 b, KELT-16 b, WASP-33 b, and WASP-103 b", Acta Astronomica, 68 (4): 371, arXiv:1812.02438, Bibcode:2018AcA....68..371M, doi:10.32023/0001-5237/68.4.4, S2CID 118895482