HD 33636

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HD 33636 A / B
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Orion
Right ascension 05h 11m 46.448s[1]
Declination +04° 24′ 12.73″[1]
Characteristics
Spectral type G0VH-03 / M6V
B−V color index 0.588 ± 0.016 / ?[2]
Astrometry
Proper motion (μ) RA: 169.0 ± 0.3[3] mas/yr
Dec.: -142.3 ± 0.3[3] mas/yr
Parallax (π) 35.6 ± 0.2[3] mas
Distance 91.6 ± 0.5 ly
(28.1 ± 0.2 pc)
Absolute magnitude (MV) 4.77 / ?
Orbit
Companion HD 33636 B
Period (P) 5.797 ± 0.002[3] yr
Semi-major axis (a) 14.2 ± 0.2 AU
Inclination (i) 4.1 ± 0.1°
Details
Mass 1.01 ± 0.02[4]/ ? M
Radius 0.97 ± 0.01[4]/ ? R
Luminosity 1.08 ± 0.003[4]/ ? L
Surface gravity (log g) 4.46 ± 0.02[4]/ ? cgs
Temperature 5979 ± 28[4]/ ? K
Age 2.5 ± 1.1[4] Gyr
Other designations
BD+04 858, HIP 24205, SAO 74702
Database references
SIMBAD data

HD 33636 is a binary system located approximately 94 light-years away in Orion constellation. The visible member HD 33636 A is a 7th magnitude yellow main-sequence star. It is located at a distance of 91.6 light years from Earth. It has Fe/H of −0.05 +/- 0.07.

A companion was discovered in 2002 with a minimum mass of planet size.[2][5] This was ascertained to be a tiny star in 2007, making it HD 33636 B.[3]

HD 33636 B[edit]

HD 33636 B was discovered in 2002 by the Keck telescope in Hawaii.[5] It was independently detected at the Haute-Provence Observatory in switzerland.[2] With this method it showed a minimum mass of 9.28 Jupiter masses, and was initially assumed to be a planet and provisionally labelled "HD 33636 b" (lower-case).

In 2007, Bean et al. used the Hubble Space Telescope (HST) and he found that this body has an inclination as little as 4.1 ± 0.1°, which yielded the true mass of 142 Jupiter masses. This is too high to be a planet. It is now classified as an M-dwarf star of spectral type M6V, "HD 33636 B" (upper-case).

This star takes 2117 days or 5.797 years to orbit at the average distance of 3.27 Astronomical Units (AU).

References[edit]

External links[edit]