HD 28185

Starbox begin
name = HD 28185 Starbox observe
epoch = J2000.0
constell = Eridanus
ra = RA|04|26|26.3205
dec = DEC|-10|33|02.955
appmag_v = +7.81
appmag_b = +8.52 Starbox character
class = G5V
b-v = 0.750
u-b = ?
variable = none Starbox astrometry
radial_v = 49.6
prop_mo_ra = 80.85
prop_mo_dec = -60.29
gal_lat = -36.9310
gal_lon = 205.5933
parallax = 21.97
p_error = 0.87
parallax_footnote = cite web|url=http://webviz.u-strasbg.fr/viz-bin/VizieR-4|title=HIP 20723|author=van Leeuwen, F.|year=2007|work=Hipparcos, the New Reduction|accessdate=2008-08-19]
absmag_v = +4.52 [Derived from apparent magnitude and parallax: $extstyle\; M\_V=m\_V-5log\_\{10\}left(frac\{100\}\{pi\}\; ight)$] Starbox detail
age = 7.5 × 10⁹
metal = 173%
mass = 0.99 ± 0.07
radius = 1.04
rotation = 30 days
luminosity = 1.33 [Derived from absolute visual magnitude: $extstyle\; L/L\_\{odot\}=100^\{(4.83-M\_V)/5\}$]
temperature = 5705 Starbox catalog
names = BD −10°919, SAO 149631, HIP 20723, GSC 05317-00733Starbox reference
Simbad = HD+28185

HD 28185 is a yellow dwarf star similar to our Sun located about 148 light-years away in the constellation Eridanus. The designation HD 28185 refers to its entry in the Henry Draper catalogue. As of 2006 the star is known to possess one long-period extrasolar planet.

Distance and visibility

According to measurements from the Hipparcos astrometric satellite, HD 28185 has a parallax of 21.97 milliarcseconds, which corresponds to a distance of 46 parsecs (148 light-years). Since the star is located further than 25 parsecs from Earth, it is not listed in the Gliese Catalogue of Nearby Stars. With an apparent magnitude of 7.81, the star is not visible with the naked eye, though it can be seen using binoculars.

tellar characteristics

HD 28185 is similar to our Sun in terms of mass, radius and luminosity. The star is on the main sequence and is generating energy by fusing hydrogen in its core. The spectral type of G5V implies HD 28185 is cooler than the Sun. Like the majority of extrasolar planet host stars, HD 28185 is metal-rich relative to the Sun, containing around 173% of the solar abundance of iron. The star rotates slower than the Sun, with a period of around 30 days, compared to 25.4 days for the Sun.

Based on the star's chromospheric activity, HD 28185 is estimated to have an age of around 2,900 million years. On the other hand, evolutionary models give an age of around 7,500 million years and a mass 0.99 times that of our Sun.cite journal | url=http://www.aanda.org/articles/aa/full/2001/45/aah3054/aah3054.html | author=Santos, N. et al. | title=The CORALIE survey for southern extra-solar planets VI. New long-period giant planets around HD 28185 and HD 213240 | journal=Astronomy and Astrophysics | volume=379 | year=2001 | issue=3 | pages=999–1004 | doi=10.1051/0004-6361:20011366 ]

Planetary system

In 2001 an extrasolar planet similar in size to Jupiter designated HD 28185 b was discovered in orbit around the star with a period of 1.04 years. Unlike many long-period extrasolar planets, it has a low orbital eccentricity. [cite journal|url=http://www.journals.uchicago.edu/doi/abs/10.1086/504701|author=Butler, R. et al.|title=Catalog of Nearby Exoplanets|journal=The Astrophysical Journal|volume=646|pages=505–522|year=2006|doi=10.1086/504701|format=abstract ( [http://exoplanets.org/planets.shtml web version] )] The planet experiences similar insolation to Earth, which has led to speculations about the possibilities for habitable moons. [cite web|url=http://nai.nasa.gov/news_stories/news_detail.cfm?ID=126|title=Extrasolar Planets with Earth-like Orbits|author=Mullen, L.|accessmonthday=22 July|accessyear=2006|year=2001] [cite journal|url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2006ApJ...649.1010J&db_key=AST&nosetcookie=1|author=Jones, Barrie W.; Sleep, P. Nick; Underwood, David R.|title=Habitability of Known Exoplanetary Systems Based on Measured Stellar Properties|journal=The Astrophysical Journal|volume=649|issue=2|year=2006|pages=1010 – 1019|doi=10.1086/506557] In addition, numerical simulations suggest that low-mass planets located in the gas giant's Trojan points would be stable for long periods. [cite journal|url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2007A%26A...474.1023S&db_key=AST&nosetcookie=1|title=Survey of the stability region of hypothetical habitable Trojan planets|author=Schwarz, R.; Dvorak, R.; Süli, Á.; Érdi, B.|journal=Astronomy and Astrophysics|volume=474|issue=3|pages=1023 – 1029|doi=10.1051/0004-6361:20077994|accessdate=2008-08-19]

The star also shows evidence of a long-term radial velocity trend, which may indicate the presence of an additional outer companion. [cite journal|author=Chauvin, G.; Lagrange, A.-M.; Udry, S.; Fusco, T.; Galland, F.; Naef, D.; Beuzit, J.-L.; Mayor, M.|year=2006|journal=Astronomy and Astrophysics|volume=456|issue=3|pages=1165 – 1172|title=Probing long-period companions to planetary hosts. VLT and CFHT near infrared coronographic imaging surveys|url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2006A%26A...456.1165C&db_key=AST&nosetcookie=1|doi=10.1051/0004-6361:20054709]

PlanetboxOrbit
exoplanet = b
mass = >5.72 ± 0.93
period = 383.0 ± 2.0
semimajor = 1.031 ± 0.060
eccentricity = 0.070 ± 0.040

ee also

* 51 Pegasi
* Iota Horologii

References

External links

* [http://simbad.u-strasbg.fr/sim-id.pl?protocol=html&Ident=HD+28185 SIMBAD: HD 28185 -- Star]
* [http://exoplanet.eu/star.php?st=HD+28185 Extrasolar Planets Encyclopaedia: Notes for star HD 28185]
* [http://www.extrasolar.net/startour.asp?StarCatId=normal&StarId=130 Extrasolar Visions: HD 28185]