| Discovery | |
|---|---|
| Discovered by | Perrieret al. |
| Discovery site | Haute-Provence Observatory inFrance |
| Discovery date | 4 April 2001[1] |
| doppler spectroscopy | |
| Orbital characteristics | |
| Apastron | 1.04 AU (156,000,000 km) |
| Periastron | 0.48 AU (72,000,000 km) |
| 0.76 ± 0.04 AU (113,700,000 ± 6,000,000 km) | |
| Eccentricity | 0.37 ± 0.082 |
| 225 ± 1.1d 0.616y | |
| 2,451,475.6 ± 5.5 | |
| 2 ± 16 | |
| Semi-amplitude | 64.1 ± 5.5 |
| Star | HD 8574 |
| Physical characteristics | |
| Mass | >1.96 ± 0.18MJ (>622M🜨) |
| Temperature | 356 K (83 °C; 181 °F) |
HD 8574 b is anextrasolar planet discovered in 2001 by a team of European astronomers usingDoppler spectroscopy as part of theELODIE Planet Search Survey, and was published in a paper with five other planets. HD 8574 b is in the orbit of host starHD 8574. The planet is at most two times the mass of Jupiter, orbiting every 227 days at three quarters of the distance between the Earth and Sun. HD 8574 b has a very elliptical orbit, far more than that of Jupiter.
The planet HD 8574 b is namedBélisama. The name was selected in theNameExoWorlds campaign byFrance, during the 100th anniversary of theIAU.Bélisama was the goddess of fire, notably of the hearth and of metallurgy and glasswork, inGaulish mythology.[2][3]
TheELODIE Planet Search Survey, undertaken using theELODIE spectrograph at theHaute-Provence Observatory in southeastern France, was a large-scale search forextrasolar planets orbitingG-type andF-type dwarf stars visible from the Northern Hemisphere through use of theradial velocity method (the orbit of a planet tugs on its host star as it orbits, causing a perceivedDoppler effect in the star'sspectrum). This survey, which started in 1994, led to the discovery of51 Pegasi b, the first extrasolar planet discovered in the orbit of a sunlike star. By 2003, the discovery of six new planets, including HD 8574 b, was announced, bringing ELODIE's planet discovery count to eighteen.[4]
HD 8574, one of the target stars of ELODIE, had been previously catalogued by theEuropean Space Agency with the release of theHipparcos catalogue in 1997. Most of HD 8574's characteristics were extracted from this catalogue for use in searching for a planet around HD 8574. The spectrum was then analyzed to see if HD 8574 were active, a factor that could mask or mimic the signal of an orbiting planet. It was found that the star was not significantly active.[4]
In the case of HD 8574, ELODIE obtained 41radial velocity measurements, which had, at the time of the discovery paper, been collected since January 11, 1998. Analysis of the collected data confirmed the existence of a planet orbiting HD 8574. Of the six, the planet HD 8574 b had the shortestorbital period, orbiting its host star under three years (unlike the five other planets that had been discovered by ELODIE at the same time).[4]
HD 8574 b was announced by theEuropean Southern Observatory on April 4, 2001.[1] The findings addressing HD 8574's discovery were published in 2003.[4]
HD 8574 is an F-type dwarf star that lies 45parsecs (146light years) away from Earth. HD 8574 has an estimated mass of 1.17 times themass of the Sun. The star also has a radius that is estimated at 1.37 timesthat of the Sun's. HD 8574 has aneffective temperature of 6080K, hotter than the Sun, and ametallicity estimated at [Fe/H] = 0.05 (12% more iron than in the Sun).[5] Additionally, with aluminosity of 2.25, HD 8574 releases more than twice the energy released by the Sun.[4]
The star has anapparent magnitude of 7.12, and is thus extremely faint (if visible at all) as seen from the unaided eye of an observer on Earth.[5][6]
HD 8574 is a large planet that orbits its host star every 227.55 days at a distance of 0.77AU, or 77% themean distance between the Earth and the Sun.[5] HD 8574 b has, of the six planets announced in a November 2003 discovery paper, the shortest orbit.[4] The planet has an estimatedmass of 2.11 times Jupiter's mass. HD 8574 b has a measuredorbital eccentricity of 0.288, denoting an elliptical orbit.[5] Jupiter, in comparison, orbits the Sun with an orbital eccentricity of 0.016, which is far more circular.[7]
