Discovery [1] | |
---|---|
Discovered by | Santos et al. |
Discovery site | La Silla Observatory |
Discovery date | October 19, 2009 |
radial velocity (HARPS) | |
Orbital characteristics [2] | |
8.8+2.5 −1.4 AU | |
Eccentricity | 0.745+0.054 −0.047 |
9971+4383 −2228 d 27.3+12.0 −6.1 yr | |
Average orbital speed | 12.2 |
Inclination | 64°+18° −23° or 116°+23° −18° |
108°+51° −82° | |
2464428+4507 −2245 | |
315.3°±3.7° | |
Semi-amplitude | 48 ± 1 [1] |
Star | HD 190984 |
Physical characteristics [2] | |
Mass | 3.58+1.2 −0.45 MJ |
HD 190984 b (also known as HIP 99496 b) is an exoplanet which orbits the F-type main sequence star HD 190984, located approximately 486 light-years away in the constellation Pavo. This planet has a minimum mass three times that of Jupiter and takes 13 years and four-and-a-half months to orbit the star at a semimajor axis of 5.5 AU with an eccentricity of 0.57. [1] This planet was detected by HARPS on October 19, 2009, together with 29 other planets.
Since this is a very long-period planet detected by the radial velocity method and this planet didn't complete its orbit during the continuous observations, the error range for orbital period is very large, at 4885 ± 1600 days or 13.37 ± 4.4 years. This puts it in the range of semimajor axes between 4.2 and 6.6 AU. So this planet will need more years of observations to better constrain the period and semimajor axis.
In 2023, the inclination and true mass of HD 190984 b were determined via astrometry, and its orbit was updated, finding a longer period and larger semi-major axis than previously estimated, although still with a large margin of error. [2]
HD 179949 is a 6th magnitude star in the constellation of Sagittarius. It is a yellow-white dwarf, a type of star hotter and more luminous than the Sun. The star is located about 90 light years from Earth and might be visible under exceptionally good conditions to an experienced observer without technical aid; usually binoculars are needed.
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. HD 28185 b orbits its sun in a circular orbit that is at the inner edge of its star's habitable zone.
Rho Indi b is an exoplanet that orbits around Rho Indi. Its semimajor axis is 2.54 AU placing just outside the star's habitable zone. The planet takes 3.7 years to orbit the star. It is over twice as massive as Jupiter. Since the inclination of the orbit to the line-of-sight was initially unknown, only a lower bound on the planet's mass could be determined. In 2023, the inclination and true mass of Rho Indi b were determined via astrometry.
HD 125612 is a binary star system with three exoplanetary companions in the equatorial constellation of Virgo. It is too dim to be visible to the naked eye, having an apparent visual magnitude of 8.31. The system is located at a distance of 188 light years from the Sun based on parallax measurements, but it is drifting closer with a radial velocity of −18 km/s.
HD 154345 is a star in the northern constellation of Hercules. With an apparent visual magnitude of +6.76 it is a challenge to view with the naked eye, but using binoculars it is an easy target. The distance to this star is 59.6 light years based on parallax, but it is drifting closer with a radial velocity of −47 km/s. At least one exoplanet is orbiting this star.
HD 17156, named Nushagak by the IAU, is a yellow subgiant star approximately 255 light-years away in the constellation of Cassiopeia. The apparent magnitude is 8.17, which means it is not visible to the naked eye but can be seen with good binoculars. A search for a binary companion star using adaptive optics at the MMT Observatory was negative.
HD 109749 is a binary star about 206 light years away in the constellation of Centaurus.
HD 117207 is a star in the southern constellation Centaurus. With an apparent visual magnitude of 7.24, it is too dim to be visible to the naked eye but can be seen with a small telescope. Based upon parallax measurements, it is located at a distance of 105.4 light-years from the Sun. The star is drifting closer with a radial velocity of −17.4 km/s. It has an absolute magnitude of 4.67.
HD 153950 is a star in the southern constellation of Scorpius, positioned about 1.2° to the west of Eta Scorpii. It has the proper name Rapeto, which was selected in the NameExoWorlds campaign by Madagascar, during the 100th anniversary of the IAU. Rapeto is a giant creature from Malagasy tales. This star is visible in a small telescope, having an apparent visual magnitude of 7.39. It is located at a distance of 158 light years from the Sun based on parallax. The star is drifting further away with a radial velocity of 33.2 km/s.
HD 30562 b is an extrasolar planet which orbits the F-type main sequence star HD 30562, located approximately 85.4 light years away in the constellation Eridanus.
HD 5388 is a single star in the southern constellation of Phoenix. It has the Gould designation 78 G. Phoenicis, while HD 5388 is the star's Henry Draper Catalogue identifier. This object has a yellow-white hue and is too faint to be readily visible to average human eyesight, having an apparent visual magnitude of 6.73. It is located at a separation of 173 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +39 km/s.
HD 181720 is an 8th-magnitude G-type main sequence star located approximately 190 light-years away in the constellation Sagittarius. This star is larger, hotter, brighter and less massive than the Sun. Also its metal content is three-tenths as much as the Sun.
HD 181720 b is an extrasolar planet which orbits the G-type main sequence star HD 181720, located approximately 190 light years away in the constellation Sagittarius. This planet has at least three-eighths the mass of Jupiter and takes over two and five-eighths years to orbit the star at a semimajor axis of 1.78 AU with an eccentricity of 0.26. This planet was detected by HARPS on October 19, 2009, together with 29 other planets.
HD 190984, also known as HIP 99496, is a star located in the southern circumpolar constellation Pavo, the peacock. It has an apparent magnitude of 8.76, making it readily visible in small telescopes, but not to the naked eye. Based on parallax measurements from the Gaia spacecraft, the object is estimated to be 486 light years away from the Solar System. It appears to be receding with a heliocentric radial velocity of 20.3 km/s.
HD 28254 is an 8th magnitude G-type main sequence star located 180 light years away in the constellation Dorado. This star is larger, cooler, brighter, and more massive than the Sun, and its metal content is 2.3 times as much as the Sun. In 2009, a gas giant planet was found in orbit around the star.
HIP 70849 b is an extrasolar planet which orbits the K-type main sequence star HIP 70849, located approximately 79 light years away in the constellation Lupus. This planet was detected by HARPS and announced on October 19, 2009, together with 31 other planets. Its parameters were initially poorly constrained, estimated to have a minimum mass of 3-15 MJ and take anywhere from 5-90 years to orbit the star at a semimajor axis of 4.5-36 AU, with the eccentricity and inclination being unknown. This was significantly updated in a December 2022 paper, which found much better constrained parameters including a high eccentricity, and in a January 2023 paper which determined the planet's inclination and true mass via astrometry.
HD 13931 is a Sun-like star in the northern constellation of Andromeda. It can be viewed with binoculars or a small telescope but is too faint to be seen with the naked eye, having an apparent visual magnitude of 7.60. This object is located at a distance of 154 light years from the Sun, as determined from its parallax, and is drifting further away with a radial velocity of +31 km/s.
HD 106515 is a binary star in the constellation of Virgo.
HD 3167 is a single, orange-hued star in the zodiac constellation of Pisces that hosts a system with three exoplanets. The star is too faint to be seen with the naked eye, having an apparent visual magnitude of 8.97. The distance to HD 3167 can be determined from its annual parallax shift of 21.1363 mas as measured by the Gaia space observatory, yielding a range of 154 light years. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.204″ per year. Since it was first photographed during the Palomar observatory sky survey in 1953, it had moved over 12.5″ by 2017. The star is moving away from the Earth with an average heliocentric radial velocity of +19.5 km/s.
HD 233731, or HAT-P-22, is a suspected multiple star system in the northern circumpolar constellation of Ursa Major. It is invisible to the naked eye, having an apparent visual magnitude of 9.732. This system is located at a distance of 267 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +13 km/s.