Upsilon Andromedae e

Upsilon Andromedae e is the proposed outermost extrasolar planet orbiting the star Upsilon Andromedae in the constellation of Andromeda. If it exists, this planet would be one of the most Jupiter-like exoplanets found in terms of mass and semi-major axis. However, subsequent studies have found that the apparent planetary signal is more likely to be an instrumental artifact.[3][4]

Upsilon Andromedae e
An artist's impression of Ups And e
Discovery
Discovered byCuriel et al.
Discovery siteBaja California
Discovery dateNovember 22, 2010 (announced)
December 2, 2010 (published)
Doppler spectroscopy
Orbital characteristics
Apastron5.2738 ± 0.0029 AU (788.95 ± 0.43 million km)
Periastron5.2175 ± 0.003 AU (780.53 ± 0.45 million km)
5.2456 ± 0.00067 AU (784.731 ± 0.100 million km)[1]
Eccentricity0.0055±0.0004[2]
3,848.86±0.74[2] d
~10.53946[2] y
367.3 ± 2.3[1]
StarUpsilon Andromedae

    Discovery

    This planet was discovered on November 22, 2010, but the discovery paper was not released until December 2.[1] It was the fourth time in 2010 that a fourth planet has been discovered in a planetary system, the others being Gliese 876 e, HD 10180 e, and HR 8799 e; in no earlier year during the exoplanet era had more than one fourth planet been discovered.

    Subsequent studies in 2011 and 2014, while finding some evidence for a fourth planet, found large inconsistencies in the estimated orbital period of Upsilon Andromedae e depending on what dataset was used,[5] suggesting that the apparent planetary signal is more likely to be an instrumental artifact.[3][4]

    Astronomers initially thought that a fourth planet in this system could not exist because it would have made the planetary system unstable and would have been ejected.[6] But in 2007, an island region of stability was reported where a fourth planet could exist.[7]

    Characteristics

    If it exists, Upsilon Andromedae e would have a minimum mass slightly greater than Jupiter's and orbit at a similar distance as Jupiter from the Sun, at 5.2456 AU compared to 5.2043 AU for Jupiter. Although only the minimum mass is determined since inclination is not yet known, its true mass might be much greater. It would take over a decade to orbit the star. At an eccentricity of 0.00536, the planet's orbit would be more circular than that of any of the planets in the Solar System.[1]

    See also
    • HIP 11915 b – another Jupiter analog discovered in 2015

    References
    1. Curiel, S.; et al. (2011). "A fourth planet orbiting υ Andromedae". Astronomy & Astrophysics. 525: A78. Bibcode:2011A&A...525A..78C. doi:10.1051/0004-6361/201015693.
    2. Ligi, R.; et al. (2012). "A new interferometric study of four exoplanet host stars : θ Cygni, 14 Andromedae, υ Andromedae and 42 Draconis". Astronomy & Astrophysics. 545: A5. arXiv:1208.3895. Bibcode:2012A&A...545A...5L. doi:10.1051/0004-6361/201219467. S2CID 10934982.
    3. McArthur, Barbara E.; et al. (2014). "Astrometry, Radial Velocity, and Photometry: The HD 128311 System Remixed with Data from HST, HET, and APT". The Astrophysical Journal. 795 (1): 41. Bibcode:2014ApJ...795...41M. doi:10.1088/0004-637X/795/1/41. S2CID 122980723.
    4. Deitrick, R.; et al. (January 2015). "The Three-dimensional Architecture of the υ Andromedae Planetary System". The Astrophysical Journal. 798 (1): 46. arXiv:1411.1059. Bibcode:2015ApJ...798...46D. doi:10.1088/0004-637X/798/1/46. S2CID 118409453.
    5. Tuomi, M.; Pinfield, D.; Jones, H. R. A. (2014). "Application of Bayesian model inadequacy criterion for multiple data sets to radial velocity models of exoplanet systems". Astronomy & Astrophysics. 532: A116. arXiv:1106.5981. Bibcode:2011A&A...532A.116T. doi:10.1051/0004-6361/201117278. S2CID 14800854.
    6. Ford, Eric B.; et al. (2005). "Planet-planet scattering in the upsilon Andromedae system". Nature. 434 (7035): 873–876. arXiv:astro-ph/0502441. Bibcode:2005Natur.434..873F. doi:10.1038/nature03427. PMID 15829958. S2CID 119496437.
    7. Rory Barnes; Richard Greenberg (2008). "Extrasolar planet interactions". Proceedings of the International Astronomical Union. 3: 469–478. arXiv:0801.3226v1. Bibcode:2008IAUS..249..469B. doi:10.1017/S1743921308016980. S2CID 17096607.
    This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.