HD 28185 Contents Distance and visibility Stellar characteristics Planetary system See...
Eridanus (constellation)G-type main-sequence starsHenry Draper Catalogue objectsHipparcos objectsPlanetary systemsDurchmusterung objects
yellow dwarfstarSunlight-yearsconstellationEridanusHenry Draper catalogueperiodextrasolar planetGaia spacecraftparallaxmilliarcsecondsparsecslight-yearsGliese Catalogue of Nearby Starsapparent magnitudenaked eyebinocularsmassradiusluminositymain sequenceenergyfusinghydrogenspectral typemetal-richironchromospheric activityevolutionary modelsextrasolar planetJupiterHD 28185 borbital eccentricityinsolationEarthhabitablemoonsTrojan pointsMagellan Planet Search Program
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
Constellation | Eridanus |
Right ascension | 04h 26m 26.3227s[1] |
Declination | −10° 33′ 02.9455″[1] |
Apparent magnitude (V) | +7.81 |
| Characteristics | |
Spectral type | G5V |
| U−B color index | ? |
| B−V color index | 0.750 |
Variable type | none |
| Astrometry | |
| Radial velocity (Rv) | 49.6 km/s |
| Proper motion (μ) | RA: 7001840710000000000♠84.071±0.045[1] mas/yr Dec.: 2998402500000000000♠−59.750±0.039[1] mas/yr |
| Parallax (π) | 25.3642 ± 0.0407[1] mas |
| Distance | 128.6 ± 0.2 ly (39.43 ± 0.06 pc) |
| Absolute magnitude (MV) | +4.68[note 1] |
| Details | |
| Mass | 1.0 ± 0.1[2] M☉ |
| Radius | 1.15 ± 0.03[2] R☉ |
| Luminosity | 1.18 ± 0.01[2] L☉ |
| Surface gravity (log g) | 4.33 ± 0.03[2] cgs |
| Temperature | 5609 ± 41[2] K |
| Metallicity | 0.24 (173%) |
| Rotation | 30 days |
| Age | 4.8 ± 4.4[2] Gyr |
| Other designations | |
BD–10°919, SAO 149631, HIP 20723, GSC 05317-00733 | |
| Database references | |
| SIMBAD | data |
| Extrasolar Planets Encyclopaedia | data |
HD 28185 is a yellow dwarf star similar to our Sun located about 128.6 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.
Contents
1 Distance and visibility
2 Stellar characteristics
3 Planetary system
4 See also
5 Notes
6 References
7 External links
Distance and visibility
According to measurements from the Gaia spacecraft, HD 28185 has a parallax of 25.3642 milliarcseconds,[1] which corresponds to a distance of 39.43 parsecs (128.6 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.
Stellar 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.[3] The higher luminosity and longer rotation period favour an older age for the star.
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.[3][4] Unlike many long-period extrasolar planets, it has a low orbital eccentricity.[5] The planet experiences similar insolation to Earth, which has led to speculations about the possibilities for habitable moons.[6][7] In addition, numerical simulations suggest that low-mass planets located in the gas giant's Trojan points would be stable for long periods.[8] The planet's existence was independently confirmed by the Magellan Planet Search Program in 2008.[9]
The star also shows evidence of a long-term radial velocity trend, which may indicate the presence of an additional outer companion.[10]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
b | ≥5.7 MJ | 1.031 ± 0.060 | 383 ± 2 | 0.07 ± 0.04 | — | — |
See also
- 51 Pegasi
- Iota Horologii
Notes
^ Derived from apparent magnitude and parallax: MV=mV−5log10(100π){displaystyle scriptstyle M_{V}=m_{V}-5log _{10}left({frac {100}{pi }}right)}
References
^ abcdef Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output .citation q{quotes:"""""""'""'"}.mw-parser-output .citation .cs1-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .citation .cs1-lock-limited a,.mw-parser-output .citation .cs1-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .citation .cs1-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Wikisource-logo.svg/12px-Wikisource-logo.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-maint{display:none;color:#33aa33;margin-left:0.3em}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
Gaia DR2 record for this source at VizieR.
^ abcdef Bonfanti, A.; et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics. 575. A18. arXiv:1411.4302. Bibcode:2015A&A...575A..18B. doi:10.1051/0004-6361/201424951.
^ abc 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.
^ "Exoplanets: The Hunt Continues!" (Press release). Garching, Germany: European Southern Observatory. April 4, 2001. Retrieved December 27, 2012.
^ 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.
^ Mullen, L. (2001). "Extrasolar Planets with Earth-like Orbits". Archived from the original on 29 September 2006. Retrieved 22 July 2006.
^ 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.
^ 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.
^ 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.
^ Chauvin, G.; Lagrange, A.-M.; Udry, S.; Fusco, T.; Galland, F.; Naef, D.; Beuzit, J.-L.; Mayor, M. (2006). "Probing long-period companions to planetary hosts. VLT and CFHT near infrared coronographic imaging surveys". Astronomy and Astrophysics. 456 (3): 1165–1172. arXiv:astro-ph/0606166. Bibcode:2006A&A...456.1165C. doi:10.1051/0004-6361:20054709.
External links
Coordinates: 
04h 26m 26.3205s, −10° 33′ 02.955″
