AF Leporis

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AF Leporis
Lepus constellation map.svg
Red circle.svg
Location of AF Leporis (circled)
Observation data
Epoch J2000        Equinox J2000
Constellation Lepus
Right ascension 05h 27m 04.76333s [1]
Declination −11° 54 03.4660 [1]
Apparent magnitude  (V)6.26 - 6.35 [2]
Characteristics
Evolutionary stage Main sequence
Spectral type F8V(n)k: [3]
Apparent magnitude  (B)6.832±0.015 [4]
Apparent magnitude  (V)6.295±0.010 [4]
Apparent magnitude  (G)6.209±0.003 [1]
Apparent magnitude  (J)5.268±0.027 [4]
Apparent magnitude  (H)5.087±0.026 [4]
Apparent magnitude  (K)4.926±0.021 [4]
Variable type RS CVn [2]
Astrometry
Radial velocity (Rv)21.10±0.37 [1]  km/s
Proper motion (μ)RA: 16.915  mas/yr [1]
Dec.: −49.318  mas/yr [1]
Parallax (π)37.2539 ± 0.0195  mas [1]
Distance 87.55 ± 0.05  ly
(26.84 ± 0.01  pc)
Absolute magnitude  (MV)4.14 [5]
Details
Mass 1.09±0.06 [6]   M
Radius 1.25±0.06 [7]   R
Luminosity (bolometric)1.84±0.01 [8]   L
Surface gravity (log g)4.30±0.05 [6]   cgs
Temperature 6130±60 [7]   K
Metallicity [Fe/H]+0.19±0.02 [7]   dex
Rotation 0.9660±0.0023  d [9]
Rotational velocity (v sin i)50±5 [7]  km/s
Age 24±3 [7]   Myr
Other designations
AF Lep, NSV  16310, BD−12 1169, FK5  2409, HD  35850, HIP  25486, HR  1817, SAO  150461, PPM  215789, TIC  94945758, TYC  5340-1141-1, GCRV  3284, GSC  05340-01141, IRAS 05247-1156 [10]
Database references
SIMBAD data

AF Leporis, also known as HD 35850, is an F-type main-sequence star located 87.5 light-years (26.8 parsecs ) away from the Solar System in the constellation of Lepus. With an apparent magnitude of 6.3, it is near the limit of naked eye visibility under ideal conditions. While some studies consider it to be a close spectroscopic binary with a separation of 0.021  AU , [8] other studies show no evidence of binarity, and it is likely that the supposed binarity is an artifact resulting from the presence of starspots. [9] [4]

Contents

A light curve for AF Leporis, plotted from TESS data AFLepLightCurve.png
A light curve for AF Leporis, plotted from TESS data

AF Leporis is a member of the Beta Pictoris moving group, with an astronomically young age of about 24 million years. It hosts a circumstellar disk and one known exoplanet. [7]

Planetary system

Two images of AF Lep b with the SPHERE instrument on the Very Large Telescope Potw2308a(1).jpg
Two images of AF Lep b with the SPHERE instrument on the Very Large Telescope

In 2023, a gas giant exoplanet was discovered in orbit around AF Leporis by direct imaging using the NIRC2 instrument at the W. M. Keck Observatory and the SPHERE instrument at the Very Large Telescope. It was also detected in astrometric data from the Hipparcos and Gaia spacecraft, allowing an accurate measurement of its mass. [7] [4] [13] Spectroscopic evidence suggests that AF Leporis b has a metal-rich atmosphere with silicate clouds. [6]

There have been multiple studies of AF Leporis b, which have found somewhat different parameters. Dynamical mass measurements range from the most recent value of 2.8  MJ [6] to 5.5 MJ. [4] Values for the planet's orbital inclination range from 50°+9°
−12°
[7] to ~98°, [13] the former consistent with the stellar inclination of 54°+11°
−9°
and suggesting an aligned system. [7] All studies have found that the planet has a fairly eccentric orbit.

The AF Leporis planetary system [6]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(years)
Eccentricity Inclination Radius
b 2.8+0.6
−0.5
  MJ
8.2+1.3
−1.7
22.3+5.6
−6.7
0.4+0.3
−0.2
55+8
−13
°
1.2-1.55  RJ
Debris disk46±9 [14] AU

See also

Related Research Articles

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<span class="mw-page-title-main">17 Leporis</span> Star in the constellation Lepus

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<span class="mw-page-title-main">Gliese 555</span> Star in the constellation Libra

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<span class="mw-page-title-main">AK Leporis</span> Star in the constellation Lepus

AK Leporis is a variable star in the southern constellation of Lepus the hare. It has an apparent visual magnitude of 6.141, so, according to the Bortle scale, it is faintly visible from rural skies at night. This star forms a visual double with Gamma Leporis—the two have an angular separation of 97″, making them difficult to separate with the naked eye even under the best conditions. Both Gamma Leporis and AK Leporis are members of the Ursa Major Moving Group of stars that share a common motion through space.

References

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  9. 1 2 Järvinen, S. P.; Arlt, R.; et al. (February 2015). "Doppler images and the underlying dynamo. The case of AF Leporis". Astronomy & Astrophysics . 574: A25. arXiv: 1412.2892 . Bibcode:2015A&A...574A..25J. doi:10.1051/0004-6361/201424229. S2CID   119205096.
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