Kelu-1

Kelu-1
Kelu-1 is located in the constellation Hydra.
Kelu-1 is located in the constellation Hydra.
     Kelu-1
Location of Kelu-1 in the constellation Hydra

Observation data
Epoch J2000[1]      Equinox J2000[1]
Constellation Hydra
Right ascension 13h 05m 40.196s[1]
Declination −25° 41′ 05.99″[1]
Characteristics
Spectral type L2:[2] / L4:[2]
Apparent magnitude (J) 13.83 ± 0.08 / 14.65 ± 0.12[3]
Apparent magnitude (H) 12.92 ± 0.03 / 13.44 ± 0.04[3]
Apparent magnitude (KS) 12.32 ± 0.02 / 12.72 ± 0.03[3]
Apparent magnitude (L') 11.42 ± 0.15 / 11.66 ± 0.15[3]
Astrometry
Proper motion (μ) RA: −299.2 ± 1.2[2] mas/yr
Dec.: −4.1 ± 1.4[2] mas/yr
Parallax (π)53.8492 ± 0.7107 mas[4]
Distance60.6 ± 0.8 ly
(18.6 ± 0.2 pc)
Orbit[3]
PrimaryA
CompanionB
Period (P)38+8
−6 yr
Semi-major axis (a)0.339+0.129
−0.066"
(6.4+2.4
−1.3 AU)
Eccentricity (e)0.82+0.1
−0.1
Inclination (i)84.9+1.0
−2.0°
Longitude of the node (Ω)39.4+2.0
−2.0°
Periastron epoch (T)2452079+200
−400 (Jun 18, 2001)
Argument of periastron (ω)
(secondary)		57.8+15.0
−20.0°
Details
Kelu-1 A
Mass0.060 ± 0.01[5] M☉
Radius0.098 R☉
Luminosity (bolometric)1.35–1.74 · 10−4[6] L☉
Temperature≈ 2020[6] K
Age0.3–0.5[3] Gyr
Kelu-1 B
Mass0.055 ± 0.01[5] M☉
Radius0.0976 R☉
Luminosity (bolometric)0.91–1.12 · 10−4[6] L☉
Temperature≈ 1840[6] K
Age0.3–0.5[3] Gyr
Other designations
Kelu-1[7][1]
Kelu 1[1]
Kelu -1[1]
LIM 1[1]
CE 298[8][1]
2MASS J13054019-2541059[1]
2MASSI J1305401-2541069[1]
2MASSW J1305402-254106[9]
DENIS-P J130540.2-254105[1]
WISEP J130539.94-254106.1[1]
WISE J130539.94-254106.1[1]
V421 Hya[1]
MUCD 11122[1]
WDS J13057-2541AB[1]
USNO-B1.0 0643-00289873[1]
[B2006] J130540.1-254110[1]
Database references
SIMBADKelu-1 AB

Kelu-1 /ˈkeɪluː/ is a system of two brown dwarfs of spectral types L2 and L4[2] located in constellation Hydra at approximately 60.6 light-years from Earth.[4] It is among the first free-floating later-than-M-type brown dwarfs discovered, and sometimes considered as prototype of L-type brown dwarfs.[10]

  1. ^ a b c d e f g h i j k l m n o p q r s Cite error: The named reference Simbad was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference Dupuy & Liu2012 was invoked but never defined (see the help page).
  3. ^ a b c d e f g Cite error: The named reference Stumpf2009 was invoked but never defined (see the help page).
  4. ^ a b Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  5. ^ a b Cite error: The named reference Gelino2006 was invoked but never defined (see the help page).
  6. ^ a b c d Cite error: The named reference Liu & Leggett2005 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Ruiz1997 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Ruiz2001 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Kirkpatrick1999 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference BH was invoked but never defined (see the help page).