HD 202628

HD 202628
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Microscopium
Right ascension 21h 18m 27.26933s[1]
Declination −43° 20′ 04.7461″[1]
Apparent magnitude (V) +6.742±0.004[2]
Characteristics
Spectral type G1.5V[2]
B−V color index +0.637±0.001[3]
Astrometry
Radial velocity (Rv)+12.071±0.0027[2] km/s
Proper motion (μ) RA: +242.190[1] mas/yr
Dec.: +21.633[1] mas/yr
Parallax (π)41.9622 ± 0.0455 mas[1]
Distance77.73 ± 0.08 ly
(23.83 ± 0.03 pc)
Absolute magnitude (MV)4.856±0.005[2]
Details[4]
Mass1.068±0.038 M☉
Radius0.951±0.013 R☉
Luminosity0.951±0.026 L☉
Surface gravity (log g)4.510±0.011 cgs
Temperature5,843±6 K
Metallicity [Fe/H]0.003±0.004 dex
Rotational velocity (v sin i)2.64±0.11[5] km/s
Age1.1±0.4 Gyr
2.3±1[6] Gyr
Other designations
CD−43°14464, GJ 825.2 & 9730, HD 202628, HIP 105184, SAO 230622, LTT 8444[7]
Database references
SIMBADdata
Exoplanet Archivedata

HD 202628 is a single[8] star in the southern constellation of Microscopium. It has an apparent visual magnitude of +6.7,[2] which makes it too faint to be readily visible to the naked eye. The star is located at a distance of 77.7 light years from the Sun based on parallax,[1] and it is drifting further away with a radial velocity of +12.1 km/s.[2] The absolute magnitude of this star is 4.86.[2]

The stellar classification of HD 202628 is G1.5V,[2] matching a yellow-hued G-type main-sequence star similar to the Sun. The chromospheric activity level and amount of X-ray emission is consistent with a star that is younger than the Sun.[6] It is spinning with a projected rotational velocity of 2.6 km/s.[5] The star has 107% of the mass of the Sun and 95% of the Sun's radius. The metallicity, or abundance of heavier elements, appears to be about the same as in the Sun. It is radiating 95% of the luminosity of the Sun from its photosphere at an effective temperature of 5,843 K.[4]

In 2010, an infrared excess from a circumstellar disk of dust was detected around this star by the Spitzer Space Telescope. The net emission at 70 microns (70 μm) is almost 20 times as high as the star's flux at this wavelength.[2] The disk has been directly imaged by the Hubble Space Telescope.[6] It is oval-shaped with an orbital eccentricity of 0.18, and is inclined at 64° to the line of sight from the Earth. The inner edge of the ring, which lies at around 158 AU from the star, is sharply defined.[6] This suggests that there is an exoplanet responsible for this defined edge, and it has been calculated as orbiting between 86 and 158 AU from HD 202628.[9]

The HD 202628 planetary system
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(years) 		Eccentricity Inclination Radius
b (unconfirmed) > 1 M🜨 86-158[9] — ~ 0.2 — —
Disk 150–220 AU 64°° —
  1. ^ a b c d e f Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d e f g h i Cite error: The named reference Faramaz_et_al_2019 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Anderson_Francis_2012 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Gáspár_et_al_2016 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference dosSantos_et_al_2016 was invoked but never defined (see the help page).
  6. ^ a b c d Cite error: The named reference Krist_et_al_2012 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Fuhrmann2017 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Nesvold_Kuchner_2015 was invoked but never defined (see the help page).