HD 28185 b

Last updated
HD 28185 b
Jkv.HD28185.b.png
An artist's impression of HD28185 b
Discovery
Discovered by Santos et al.
Discovery site La Silla Observatory
Discovery dateApril 4, 2001 [1]
Radial velocity (CORALIE)
Orbital characteristics [2]
1.035+0.042
−0.046
  AU
Eccentricity 0.055+0.004
−0.003
1.056 ± 0.0002 years (385.704 ± 0.073  d)
2452262.394+3.714
−3.315
356.596°+3.495°
−3.155°
Semi-amplitude 163.657+0.653
−0.533
Star HD 28185
Physical characteristics [2]
Mass 5.837+0.486
−0.510
  MJ

    HD 28185 b is an extrasolar planet 128 light-years away from Earth in the constellation of Eridanus. The planet was discovered orbiting the Sun-like star HD 28185 in April 2001 as a part of the CORALIE survey for southern extrasolar planets, and its existence was independently confirmed by the Magellan Planet Search Survey in 2008. [3] HD 28185 b orbits its sun in a circular orbit that is at the inner edge of its star's habitable zone. [4]

    Contents

    Discovery

    HD 28185 b was discovered by detecting small periodic variations in the radial velocity of its parent star caused by the gravitational attraction of the planet. This was achieved by measuring the Doppler shift of the star's spectrum. In 2001 it was announced that HD 28185 exhibited a wobble along the line-of-sight with a period of 383 days, with an amplitude indicating a minimum mass 5.72 times that of Jupiter. [1] [5]

    Orbit and mass

    HD 28185 b takes 1.04 years to orbit its parent star. Unlike most known long-period planets, the orbit of HD 28185 b has a low eccentricity, comparable to that of Mars in the Solar System. [6] The orbit lies entirely within its star's habitable zone. [4]

    The amplitude of the radial velocity oscillations means that the planet has a mass at least 5.7 times that of Jupiter in the Solar System. However, the radial velocity method only yields a minimum value on the planet's mass, depending on the orbital inclination to our line-of-sight. Therefore, the true mass of the planet may be much greater than this lower limit.

    Characteristics

    Given the planet's high mass, it is most likely to be a gas giant with no solid surface. Since the planet has only been detected indirectly through observations of the star, properties such as its radius, composition, and temperature are unknown. Periastron (0.959 AU), semimajor axis (1.031 AU) and apastron (1.102 AU) irradiances are 112%, 96.6% and 84.5% that of the Earth. [note 1]

    Since HD 28185 b orbits in its star's habitable zone, some have speculated on the possibility of life on worlds in the HD 28185 system. [7] While it is unknown whether gas giants can support life, simulations of tidal interactions suggest that HD 28185 b could harbor Earth-mass satellites in orbit around it for many billions of years. [8] Such moons, if they exist, may be able to provide a habitable environment, though it is unclear whether such satellites would form in the first place. [9] Additionally, a small planet in one of the gas giant's Trojan points could survive in a habitable orbit for long periods. [10] The high mass of HD 28185 b, of over six Jupiter masses, actually makes either of these scenarios more likely than if the planet was about Jupiter's mass or less.

    See also

    Notes

    1. From Star radius is 1.15 times solar, temperature is 5609 K compared to the sun 5777 K. Irradiance is given by bolometric luminosity divided by square of distance, flux divided by Solar Constant, ratio relative to Earth.

    Related Research Articles

    <span class="mw-page-title-main">Exoplanet</span> Planet outside the Solar System

    An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, initially detected in 1988, was confirmed in 2003. As of 1 January 2023, there are 5,297 confirmed exoplanets in 3,904 planetary systems, with 850 systems having more than one planet.

    <span class="mw-page-title-main">47 Ursae Majoris</span> Star in the constellation Ursa Major

    47 Ursae Majoris, formally named Chalawan, is a yellow dwarf star approximately 46 light-years from Earth in the constellation of Ursa Major. As of 2011, three extrasolar planets are believed to orbit the star.

    HD 169830 is a star in the southern constellation of Sagittarius. It has a yellow-white hue and is dimly visible to the naked eye with an apparent visual magnitude of +5.90. The star is located at a distance of 120 light years from the Sun based on parallax. It is drifting closer with a radial velocity of −17.3 km/s, and is predicted to come as close as 20.7 ly (6.4 pc) in 2.08 million years. HD 169830 is known to be orbited by two large Jupiter-like exoplanets.

    HD 69830 is a yellow dwarf star located approximately 41 light-years away in the constellation of Puppis. In 2005, the Spitzer Space Telescope discovered a narrow ring of warm debris orbiting the star. The debris ring contains substantially more dust than the Solar System's asteroid belt. In 2006, three extrasolar planets with minimum masses comparable to Neptune were confirmed in orbit around the star, located interior to the debris ring.

    <span class="mw-page-title-main">Exomoon</span> Moon beyond the Solar System

    An exomoon or extrasolar moon is a natural satellite that orbits an exoplanet or other non-stellar extrasolar body.

    HD 28185 is a yellow dwarf star similar to the Sun located 128 light-years away from Earth in the constellation Eridanus. The designation HD 28185 refers to its entry in the Henry Draper catalogue. The star is known to possess one long-period extrasolar planet.

    <span class="mw-page-title-main">23 Librae b</span> Extrasolar planet in the constellation Libra

    23 Librae b, also known as HD 134987 b, is an extrasolar Jovian planet discovered in November 1999 orbiting the star 23 Librae. It orbits in its star's habitable zone.

    <span class="mw-page-title-main">Gliese 876 c</span> Gas giant orbiting Gliese 876

    Gliese 876 c is an exoplanet orbiting the red dwarf Gliese 876, taking about 30 days to complete an orbit. The planet was discovered in April 2001 and is the second planet in order of increasing distance from its star.

    <span class="mw-page-title-main">Gliese 876 b</span> Extrasolar planet orbiting Gliese 876

    Gliese 876 b is an exoplanet orbiting the red dwarf Gliese 876. It completes one orbit in approximately 61 days. Discovered in June 1998, Gliese 876 b was the first planet to be discovered orbiting a red dwarf.

    <span class="mw-page-title-main">16 Cygni Bb</span> Extrasolar planet

    16 Cygni Bb or HD 186427 b is an extrasolar planet approximately 69 light-years away in the constellation of Cygnus. The planet was discovered orbiting the Sun-like star 16 Cygni B, one of two solar-mass (M) components of the triple star system 16 Cygni in 1996. It orbits its star once every 799 days and was the first eccentric Jupiter and planet in a double star system to be discovered. The planet is abundant in lithium.

    Upsilon Andromedae d (υ Andromedae d, abbreviated Upsilon And d, υ And d), formally named Majriti, is a super-Jupiter exoplanet orbiting within the habitable zone of the Sun-like star Upsilon Andromedae A, approximately 44 light-years (13.5 parsecs, or nearly 4.163×1014 km) away from Earth in the constellation of Andromeda. Its discovery made it the first multiplanetary system to be discovered around a main sequence star, and the first such system known in a multiple star system. The exoplanet was found by using the radial velocity method, where periodic Doppler shifts of spectral lines of the host star suggest an orbiting object.

    <span class="mw-page-title-main">47 Ursae Majoris b</span> Gas giant orbiting the star 47 Ursae Majoris

    47 Ursae Majoris b, formally named Taphao Thong, is a gas planet and an extrasolar planet approximately 46 light-years from Earth in the constellation of Ursa Major. The planet was discovered located in a long-period orbit around the star 47 Ursae Majoris in January 1996 and as of 2011 it is the innermost of three known planets in its planetary system. It has a mass at least 2.53 times that of Jupiter.

    HD 70642 is a star with an exoplanetary companion in the southern constellation of Puppis. It has an apparent visual magnitude of +7.17, which is too dim to be readily visible to the naked eye. The system is located at a distance of 95.6 light-years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of +49.4 km/s. It came to within 55.3 ly of the Solar System some 329,000 years ago.

    Pi Mensae b, also known as HD 39091 b, is an extrasolar planet approximately 59 light-years away in the constellation of Mensa. The planet was announced orbiting the yellow main-sequence star Pi Mensae in October 2001.

    HD 99109 is an orange-hued star with an exoplanetary companion in the constellation of Leo. It has an absolute visual magnitude of +9.10, which is too faint to be visible to the naked eye. The distance to this system is 179 light-years based on parallax, and it is drifting further away with a radial velocity of +33 km/s. The star is one and half degrees away from the celestial equator to the south.

    HD 188015 b is an extrasolar planet announced by the California and Carnegie Planet Search team in 2005. Like majority of known planets, it was discovered using the radial velocity method.

    HD 210277 b is an extrasolar planet orbiting the star HD 210277. It was discovered in September 1998 by the California and Carnegie Planet Search team using the highly successful radial velocity method. The planet is at least 24% more massive than Jupiter. The mean distance of the planet from the star is slightly more than Earth's distance from the Sun. However, the orbit is very eccentric, so at periastron this distance is almost halved, and at apastron it is as distant as Mars is from the Sun.

    HD 102117 b, formally named Leklsullun, is a planet that orbits the star HD 102117. The planet is a small gas giant a fifth the size of Jupiter. It orbits very close to its star, but not in a "torch orbit" like the famous 51 Pegasi b. It is one of the smallest extrasolar planets discovered so far.

    HD 40307 b is an extrasolar planet orbiting the star HD 40307, located 42 light-years away in the direction of the southern constellation Pictor. The planet was discovered by the radial velocity method, using the European Southern Observatory's HARPS apparatus, in June 2008. It is the second smallest of the planets orbiting the star, after HD 40307 e. The planet is of interest as this star has relatively low metallicity, supporting a hypothesis that different metallicities in protostars determine what kind of planets they will form.

    <span class="mw-page-title-main">Discoveries of exoplanets</span> Detecting planets located outside the Solar System

    An exoplanet is a planet located outside the Solar System. The first evidence of an exoplanet was noted as early as 1917, but was not recognized as such until 2016; no planet discovery has yet come from that evidence. What turned out to be the first detection of an exoplanet was published among a list of possible candidates in 1988, though not confirmed until 2003. The first confirmed detection came in 1992, with the discovery of terrestrial-mass planets orbiting the pulsar PSR B1257+12. The first confirmation of an exoplanet orbiting a main-sequence star was made in 1995, when a giant planet was found in a four-day orbit around the nearby star 51 Pegasi. Some exoplanets have been imaged directly by telescopes, but the vast majority have been detected through indirect methods, such as the transit method and the radial-velocity method. As of 1 January 2023, there are 5,297 confirmed exoplanets in 3,904 planetary systems, with 850 systems having more than one planet. This is a list of the most notable discoveries.

    References

    1. 1 2 "Exoplanets: The Hunt Continues!" (Press release). Garching, Germany: European Southern Observatory. April 4, 2001. Retrieved December 27, 2012.
    2. 1 2 Feng, Fabo; Butler, R. Paul; et al. (August 2022). "3D Selection of 167 Substellar Companions to Nearby Stars". The Astrophysical Journal Supplement Series . 262 (21): 21. arXiv: 2208.12720 . Bibcode:2022ApJS..262...21F. doi:10.3847/1538-4365/ac7e57. S2CID   251864022.
    3. Minniti, Dante; et al. (2009). "Low-Mass Companions for Five Solar-Type Stars From the Magellan Planet Search Program". The Astrophysical Journal . 693 (2): 1424–1430. arXiv: 0810.5348 . Bibcode:2009ApJ...693.1424M. doi:10.1088/0004-637X/693/2/1424. S2CID   119224845.
    4. 1 2 Jones, Barrie W.; Sleep, P. Nick; Underwood, David R. (2006). "Habitability of Known Exoplanetary Systems Based on Measured Stellar Properties". The Astrophysical Journal . 649 (2): 1010–1019. arXiv: astro-ph/0603200 . Bibcode:2006ApJ...649.1010J. doi:10.1086/506557. S2CID   119078585.
    5. Santos, N.; et al. (2001). "The CORALIE survey for southern extra-solar planets VI. New long-period giant planets around HD 28185 and HD 213240". Astronomy and Astrophysics . 379 (3): 999–1004. arXiv: astro-ph/0106255 . Bibcode:2001A&A...379..999S. doi:10.1051/0004-6361:20011366. S2CID   59061741. Archived from the original on 2006-07-13.
    6. Butler, R. P.; et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal. 646 (1): 505–522. arXiv: astro-ph/0607493 . Bibcode:2006ApJ...646..505B. doi:10.1086/504701. S2CID   119067572.
    7. Mullen, L. (2001). "Extrasolar Planets with Earth-like Orbits". Archived from the original on 29 September 2006. Retrieved 22 July 2006.
    8. Barnes, J., O'Brien, D. (2002). "Stability of Satellites around Close-in Extrasolar Giant Planets". Astrophysical Journal . 575 (2): 1087–1093. arXiv: astro-ph/0205035 . Bibcode:2002ApJ...575.1087B. doi:10.1086/341477. S2CID   14508244.{{cite journal}}: CS1 maint: multiple names: authors list (link)
    9. Canup, R.; Ward, W. (2006). "A common mass scaling for satellite systems of gaseous planets". Nature . 441 (7095): 834–839. Bibcode:2006Natur.441..834C. doi:10.1038/nature04860. PMID   16778883. S2CID   4327454.
    10. Schwarz, R.; Dvorak, R.; Süli, Á.; Érdi, B. (2007). "Survey of the stability region of hypothetical habitable Trojan planets". Astronomy and Astrophysics . 474 (3): 1023–1029. Bibcode:2007A&A...474.1023S. doi: 10.1051/0004-6361:20077994 .