Beyond Earthly Skies Sunday, July 5, 2015 Giant Planet around Aldebaran Aldebaran is an orange giant star located approximately 65 light years away in the constellation Taurus. It is the brightest star in the constellation Taurus and is also one of the brightest stars in the night sky. Aldebaran is currently in an advance stage of stellar evolution and has expanded to 44.2 times the Sun’s diameter. The surface temperature of Aldebaran is about 4,000 K and the star shines with ~500 times the Sun’s luminosity. Figure 1: Artist’s impression of a giant planet. Using new radial velocity measurements combined with data from observations stretching back 30 years, Hatzes et al. (2015) present the detection of a giant planet around Aldebaran. The amplitude of the radial velocity curve of Aldebaran indicates how much back and forth motion the star is experiencing due to the gravitational tugging from a companion planet. This enables the mass of the planetary companion around Aldebaran to be determined. Assuming Aldebaran has 1.13 ± 0.11 times the Sun’s mass, its planetary companion is estimated to have at least 6.47 ± 0.53 times the mass of Jupiter. With such a mass, the planetary companion is a giant planet. It orbits Aldebaran at a distance of 1.46 ± 0.27 AU, and has an orbital period of 628.96 ± 0.9 days. Aldebaran is a giant star and long-lived features on the star’s surface may create radial velocity signatures that can mimic the presence of a planet. These surface features can last for up to several years. As a result, three decades of radial velocity data is needed to show that the period of 628.96 ± 0.9 days in the radial velocity curve is consistent enough to be attributed to a giant planet. This newly discovered giant planet around Aldebaran resembles the giant planets found around other giant stars. These planets tend to have between 3 to 14 times the mass of Jupiter and have orbital radii of roughly 2 AU. Figure 2: Radial velocity measurements for Aldebaran from 7 data sets spanning three decades. Hatzes et al. (2015). Figure 3: Radial velocity measurements for Aldebaran from 7 data sets phased to the orbital period of the giant planet. Hatzes et al. (2015). Reference: Hatzes et al. (2015), “Long-lived, long-period radial velocity variations in Aldebaran: A planetary companion and stellar activity”, arXiv:1505.03454 [astro-ph.SR] Posted by Koh Xuan Yang at 7:00 AM Email ThisBlogThis!Share to XShare to FacebookShare to Pinterest Newer Post Older Post Home Blog Archive ► 2016 (133) ► August (4) ► July (32) ► June (30) ► May (23) ► April (13) ► February (9) ► January (22) ▼ 2015 (137) ► December (39) ► November (2) ► September (2) ► August (2) ▼ July (27) A Population of Extremely Long Duration Gamma-Ray ... Ultra-Diffuse Galaxies in the Virgo Cluster WOH G64 is a Stellar Behemoth with a Thick Disk Properties of a Newly Discovered Super-Neptune Properties of Oxygen Sequence Wolf-Rayet Stars A Saturn-Mass Planet beyond the Snowline of an M D... Two Record-Breaking Compact Stellar Systems Properties of a Pair of Juvenile Brown Dwarfs Hot-Neptune GJ 436b has a Comet-Like Tail Illuminating the Dark Sides of Tidally-Locked Planets Forming Graphite-Like Carbon in the Atmosphere of ... Saturn’s Phoebe Ring is Even Larger than Thought Birth of a Supermassive Black Hole Detection of a Brown Dwarf Orbiting a Sun-Like Star The Three Planets of Kepler-138 Classifying Planets, Brown Dwarfs & Stars A Venus-Mass Planet Orbiting a Brown Dwarf Identification of a Young Planetary-Mass Brown Dwarf Deuterium Fusion in the Cores of Inflated Hot-Jupi... Capturing Planetesimals from a Passing Star An Intensely Irradiated Hot-Jupiter in a Polar Orbit Discovery of an Inflated Massive Hot-Jupiter Giant Planet around Aldebaran A Low-Density Transiting Super-Neptune Case for a Low Mass Black Hole Vanishing Behind a Red Dwarf Star Discovery of a Highly Inflated Hot Jupiter ► May (26) ► April (11) ► March (14) ► February (10) ► January (4) ► 2014 (94) ► November (1) ► October (14) ► September (2) ► August (16) ► July (32) ► June (3) ► May (10) ► April (10) ► February (2) ► January (4) ► 2013 (108) ► December (1) ► November (3) ► October (30) ► September (15) ► August (7) ► July (1) ► June (4) ► May (14) ► April (8) ► March (10) ► February (10) ► January (5) ► 2012 (40) ► December (9) ► October (1) ► August (13) ► June (3) ► May (2) ► March (6) ► February (6) ► 2011 (28) ► November (1) ► September (1) ► July (2) ► June (2) ► May (3) ► April (5) ► March (5) ► February (6) ► January (3) ► 2010 (35) ► December (6) ► November (2) ► October (2) ► September (2) ► August (2) ► July (6) ► June (2) ► April (4) ► March (3) ► February (6) Search This Blog Awesome Inc. theme. Powered by Blogger.