Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Microscopium |
Right ascension | 20h 44m 10.2208s [1] |
Declination | −39° 13′ 30.850″ [1] |
Apparent magnitude (V) | 9.51 |
Characteristics | |
Spectral type | F5V [2] |
Apparent magnitude (B) | ~9.96 [2] |
Apparent magnitude (V) | ~9.54 [2] |
Apparent magnitude (J) | 8.648 ± 0.027 [2] |
Apparent magnitude (H) | 8.414 ± 0.042 [2] |
Apparent magnitude (K) | 8.396 ± 0.023 [2] |
Astrometry | |
Proper motion (μ) | RA: 30.480±0.677 [1] mas/yr Dec.: 57.998±0.753 [1] mas/yr |
Parallax (π) | 6.32 ± 0.25 mas [1] |
Distance | 520 ± 20 ly (158 ± 6 pc) |
Details | |
Mass | 1.28 −0.19+0.09 M☉ |
Radius | 1.236 −0.046+0.059 R☉ |
Temperature | 6400 ± 100 K |
Metallicity | 0 ± 0.1 |
Other designations | |
Database references | |
SIMBAD | data |
WASP-7, also identified as HD 197286, is a type F star located about 520 light years away in the constellation Microscopium. This star is a little larger and about 28% more massive than the Sun and is also brighter and hotter. At magnitude 9 the star cannot be seen by the naked eye but is visible through a small telescope. [2]
The SuperWASP project announced an extrasolar planet, WASP-7b, orbiting this star in 2008. The planet appears to be another hot Jupiter, a dense planet with Jupiter's mass orbiting very close to a hot star and thus emitting enough heat to shine. [3]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
WASP-7b | 0.96+0.12 −0.18 MJ | 0.0618+0.0014 −0.0033 | 4.954658+0.000055 −0.000043 | 0.0173+0.0009 −0.0011 [4] | — | — |
Hot Jupiters are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter but that have very short orbital periods. The close proximity to their stars and high surface-atmosphere temperatures resulted in their informal name "hot Jupiters".
HD 168443 is an ordinary yellow-hued star in the Serpens Cauda segment of the equatorial constellation of Serpens. It is known to have two substellar companions. With an apparent visual magnitude of 6.92, the star lies just below the nominal lower brightness limit of visibility to the normal human eye. This system is located at a distance of 127 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −48.7 km/s.
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 130322 is a star with a close orbiting exoplanet in the constellation of Virgo. The distance to this system is 104 light years, as determined using parallax measurements. It is drifting closer to the Sun with a radial velocity of −12.4 km/s. With an apparent visual magnitude of 8.04, it is too dim to be visible to the naked eye; requiring binoculars or a small telescope to view. Being almost exactly on the celestial equator the star is visible everywhere in the world except for the North Pole. The star shows a high proper motion, traversing the celestial sphere at an angular rate of 0.197 arcsec yr−1.
HD 189733, also catalogued as V452 Vulpeculae, is a binary star system 64.5 light-years away in the constellation of Vulpecula. The primary star is suspected to be an orange dwarf star, while the secondary star is a red dwarf star. Given that this system has the same visual magnitude as HD 209458, it promises much for the study of close transiting extrasolar planets. The star can be found with binoculars 0.3 degrees east of the Dumbbell Nebula (M27).
HD 189733 b is an exoplanet in the constellation of Vulpecula approximately 64.5 light-years away from the Solar System. Astronomers in France discovered the planet orbiting the star HD 189733 on October 5, 2005, by observing its transit across the star's face. With a mass 11.2% higher than that of Jupiter and a radius 11.4% greater, HD 189733 b orbits its host star once every 2.2 days at an orbital speed of 152.0 kilometers per second, making it a hot Jupiter with poor prospects for extraterrestrial life.
WASP-7b is an extrasolar planet discovered in 2008. This 5-day period planet is slightly smaller than Jupiter, roughly the same mass and more dense.
WASP-10 is a star in the constellation Pegasus. The SuperWASP project has observed and classified this star as a variable star, perhaps due to the eclipsing planet.
WASP-4 is a G-type main-sequence star approximately 891 light-years away in the constellation of Phoenix. Despite its advanced age, the star is rotating rapidly, being spun up by the tides raised by a giant planet on a close orbit.
WASP-5 is a magnitude 12 G-type main-sequence star located about 1,020 light-years away in the Phoenix constellation. The star is likely older than the Sun, slightly enriched in heavy elements and is rotating rapidly, being spun up by the tides raised by the giant planet on a close orbit.
HAT-P-14b, officially named Sissi also known as WASP-27b, is an extrasolar planet located approximately 224.2 ± 0.6 parsecs (731.2 ± 2.0 ly) away in the constellation of Hercules, orbiting the 10th magnitude F-type main-sequence star HAT-P-14. This planet was discovered in 2010 by the HATNet Project using the transit method. It was independently detected by the SuperWASP project.
HD 15082 is a star located roughly 397 light years away in the northern constellation of Andromeda. The star is a Delta Scuti variable and a planetary transit variable. A hot Jupiter type extrasolar planet, named WASP-33b or HD 15082b, orbits this star with an orbital period of 1.22 days. It is the first Delta Scuti variable known to host a planet.
WASP-24 is an F-type star with the Hot Jupiter planet WASP-24b in orbit. WASP-24 is slightly larger and more massive than the Sun, it is also has a similar Metallicity and is hotter than the Sun. WASP-24 was first observed by the SuperWASP planet-searching organization, which flagged it as a potential host to a planet before following up with radial velocity and spectral measurements. Analysis of these confirmed the planetary nature of WASP-24b, which was later released to the public on the SuperWASP website.
WASP-44 is a G-type star about 1,180 light-years away in the constellation Cetus that is orbited by the Jupiter-size planet WASP-44b. The star is slightly less massive and slightly smaller than the Sun; it is also slightly cooler, but is more metal-rich. The star was observed by SuperWASP, an organization searching for exoplanets, starting in 2009; manual follow-up observations using WASP-44's spectrum and measurements of its radial velocity led to the discovery of the transiting planet WASP-44b. The planet and its star were presented along with WASP-45b and WASP-46b on May 17, 2011 by a team of scientists testing the idea that hot Jupiters tend to have circular orbits, an assumption that is made when the orbital eccentricity of such planets are not well-constrained.
WASP-121b, formally named Tylos, is an exoplanet orbiting the star WASP-121. WASP-121b is the first exoplanet found to contain water in an extrasolar planetary stratosphere. WASP-121b is in the constellation Puppis, and is about 858 light-years from Earth.
HD 146389, is a star with a yellow-white hue in the northern constellation of Hercules. The star was given the formal name Irena by the International Astronomical Union in January 2020. It is invisible to the naked eye with an apparent visual magnitude of 9.4 The star is located at a distance of approximately 446 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −9 km/s. The star is known to host one exoplanet, designated WASP-38b or formally named 'Iztok'.