Saffar (exoplanet)
Exoplanet Saffar |
|
---|---|
Artist's impression of the planet and its central star | |
Constellation | Andromeda |
Position equinox : J2000.0 |
|
Right ascension | 01h 36m 47.843s |
declination | + 41 ° 24 ′ 19.65 ″ |
Orbit data | |
Central star | Titawin A |
Major semi-axis | 0.05922166 ± 0.00000020 AU |
eccentricity | 0.02150 ± 0.00070 |
Period of circulation | 4.617033 ± 0.000023 |
Further data | |
Minimum dimensions | 0.6876 ± 0.0044 M J |
distance | 13.57 ± 0.02 pc |
history | |
discovery | Marcy et al. |
Date of discovery | 1996 |
Catalog names | |
υ And b, 50 And b, HR 458 b, GJ 61 b, HD 9826 b |
Saffar ( Upsilon Andromedae b , also abbreviated υ And b ) is an exoplanet that the approximately 44.25 light years from the sun distant main sequence star Titawin A in the binary system Titawin ( Upsilon Andromedae ) in the constellation Andromeda orbits. It is the innermost of the four known planets in the star's planetary system .
Origin of name
Like all exoplanets, Saffar was originally designated with the star's official name and a lowercase letter, according to the order in which it was discovered. After a public IAU competition , on December 15, 2015, it was given an official name after Ibn as-Saffar , an 11th-century Arab astronomer in al-Andalus .
discovery
The planet was discovered in June 1996 by a team of astronomers led by Geoffrey Marcy and R. Paul Butler using the radial velocity method and its discovery was published in 1997 together with the planets Tau Bootis b and 55 Cancri b . It was one of the first known exoplanets around a main sequence star.
properties
Saffar orbits its central star at a distance of only around 0.06 AU in approximately 4.6 days. Its minimum mass is a little more than two thirds of the mass of Jupiter . It belongs to the planetary class of the Hot Jupiters , which as gas giants orbit their central star at a very short distance. The actual mass of υ And b could be around 1.4 Jupiter's masses, the orbital inclination around 25 °.
Measurements by the Spitzer Space Telescope indicate a temperature difference on the planet between the side facing away from or facing the star of around 1,400 ° C. Assuming a Jupiter-like atmosphere, Saffar could have clouds of silicate and iron high in its atmosphere. According to polarimetric measurements, the planet has a geometric albedo of 0.35 and is thus comparable to the planet Neptune in the solar system.
Individual evidence
- ↑ VizieR: HIP 7513. Retrieved May 17, 2015 .
- ↑ a b c d NASA Exoplanet Archive: ups And b. Retrieved May 17, 2015 .
- ↑ International Astronomical Union: NameExoWorlds - The Approved Names. Retrieved January 3, 2016 .
- ^ Butler, R. Paul et al .: Three New "51 Pegasi-Type" Planets . bibcode : 1997ApJ ... 474L.115B .
- ^ Curiel, S. et al .: A fourth planet orbiting υ Andromedae . bibcode : 2011A & A ... 525A..78C .
- ^ McArthur, Barbara E. et al .: New Observational Constraints on the υ Andromedae System with Data from the Hubble Space Telescope and Hobby-Eberly Telescope . bibcode : 2010ApJ ... 715.1203M .
- ↑ Harrington, J .; Hansen, BM; Luszcz, SH; Seager, S .; Deming, D .; Menou, K .; Cho, JY; Richardson, LJ: The phase-dependent Infrared brightness of the extrasolar planet upsilon Andromedae b . arxiv : astro-ph / 0610491 .
- ↑ Sudarsky, David et al .: Theoretical Spectra and Atmospheres of Extrasolar Giant Planets . arxiv : astro-ph / 0210216 .
- ↑ Berdyugina, SV; Berdyugin, AV; Piirola, V .: Upsilon Andromedae b in polarized light: New constraints on the planet size, density and albedo . arxiv : 1109.3116 .