Astronomy:KELT-1

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Short description: Star in the constellation Andromeda
KELT-1
Observation data
Equinox J2000.0]] (ICRS)
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[3] mas
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°
Observed separation
(projected)
154±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
TYC 2785-2130-1, GSC 02785-02130, 2MASS J00012691+3923017[1]
Database references
SIMBADdata

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]

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

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

Brown dwarf/planet 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

References

  1. 1.0 1.1 1.2 "KELT-1". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=KELT-1. 
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Siverd, Robert J.; Beatty, Thomas G.; Pepper, Joshua; Eastman, Jason D.; Collins, Karen; Bieryla, Allyson; Latham, David W.; Buchhave, Lars A. 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, doi:10.1088/0004-637X/761/2/123, Bibcode2012ApJ...761..123S 
  3. 3.0 3.1 3.2 3.3 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode2021A&A...649A...1G.  Gaia EDR3 record for this source at VizieR.
  4. 4.0 4.1 4.2 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, doi:10.3847/1538-4365/aae5fb, Bibcode2018ApJS..239...14J 
  5. 5.0 5.1 Beatty, Thomas G.; Wong, Ian; Fetherolf, Tara; Line, Michael R.; Shporer, Avi; Stassun, Keivan G.; Ricker, George R.; Seager, Sara et al. (2020), "The TESS phase curve of KELT-1b suggests a high dayside albedo", The Astronomical Journal 160 (5): 211, doi:10.3847/1538-3881/abb5aa, Bibcode2020AJ....160..211B 
  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, doi:10.3847/1538-3881/ab33fc, Bibcode2019AJ....158..166B 
  7. 7.0 7.1 Maciejewski, G.; Fernández, M.; Aceituno, F.; Martín-Ruiz, S.; Ohlert, J.; Dimitrov, D.; Szyszka, K.; von Essen, C. et al. (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, doi:10.32023/0001-5237/68.4.4, Bibcode2018AcA....68..371M 

Coordinates: Sky map 00h 01m 26.9169s, +39° 23′ 01.7821″