Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Delphinus |
A [1] | |
Right ascension | 20h 30m 54.1279s [2] |
Declination | +06° 25′ 46.338″ [2] |
Apparent magnitude (V) | +11.98 [3] |
C [a 1] | |
Right ascension | ~20h 30m 54s [1] |
Declination | ~+06° 25′ 46″ [1] |
Apparent magnitude (V) | 15.38 [1] |
Orbit [4] | |
Primary | WASP-2A |
Companion | WASP-2B |
Semi-major axis (a) | 106″ |
Characteristics | |
Spectral type | K1.5V + K2-M3 [5] |
Apparent magnitude (B) | ~13 [3] |
Apparent magnitude (V) | ~11.98 [3] |
Apparent magnitude (J) | 10.166±0.027 [3] |
Apparent magnitude (H) | 9.752±0.026 [3] |
Apparent magnitude (K) | 9.632±0.024 [3] |
Astrometry | |
Proper motion (μ) | RA: 5.936±0.101 [2] mas/yr Dec.: −48.279±0.082 [2] mas/yr |
Parallax (π) | 6.4980 ± 0.0686 mas [2] |
Distance | 502 ± 5 ly (154 ± 2 pc) |
Details [6] | |
WASP-2A | |
Mass | 0.843±0.033 M☉ |
Radius | 0.821±0.013 R☉ |
Temperature | 5170±60 K |
Age | 7.6+2.5 −3.3 Gyr |
WASP-2B | |
Mass | 0.48 [1] M☉ |
Temperature | 3523+28 −19 K |
Other designations | |
Database references | |
SIMBAD | data |
WASP-2 is a binary star system in the Delphinus constellation located about 500 light-years away. [3] The primary is magnitude 12 orange dwarf star, orbited by red dwarf star on wide orbit. [4] [7] The star system shows an infrared excess noise of unknown origin. [8]
This star has one extrasolar planet WASP-2b, detected by the SuperWASP project in 2006. [9]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | 0.882±0.027 MJ | 0.0308±0.0004 | 2.15222144 (± 4e-07) | 0 | — | 1.06±0.024 RJ |
In 2008 a study was undertaken of fourteen stars with exoplanets that were originally discovered using the transit method through relatively small telescopes. These systems were re-examined with the 2.2 m (87 in) reflector telescope at the Calar Alto Observatory in Spain. This star system, along with two others, was determined to be a previously unknown binary star system. The previously unknown secondary star is a dim magnitude 15 M-type star separated by about 111 AU from the primary, appearing offset from the primary by about one arc second in the images. This discovery resulted in a recalculation of parameters for both the planet and the primary star. [1]
The re-examination of the WASP-2 spectrum in 2015, have resulted in the measurement of stellar companion temperature equal to 3513±28 K, and angular separation of 0.73 arc second. [10]
HD 219134 is a main-sequence star in the constellation of Cassiopeia. It is smaller and less luminous than the Sun, with a spectral class of K3V, which makes it an orange-hued star. HD 219134 is relatively close to our system, with an estimated distance of 21.34 light years. This star is close to the limit of apparent magnitude that can still be seen by the unaided eye. The limit is considered to be magnitude 6 for most observers. This star has a magnitude 9.4 optical companion at an angular separation of 106.6 arcseconds.
WASP-8 is a binary star system 294 light-years away. The star system is much younger than the Sun at 300 million to 1.2 billion years age, and is heavily enriched in heavy elements, having nearly twice the concentration of iron compared to the Sun.
WASP-11/HAT-P-10 is a binary star. It is a primary main-sequence orange dwarf star. Secondary is M-dwarf with a projected separation of 42 AU. The system is located about 424 light-years away in the constellation Aries.
XO-2 is a binary star system about 490 light-years away in the constellation Lynx. It consists of two components, XO-2N and XO-2S, both of which host planetary systems.
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.
HAT-P-17 is a K-type main-sequence star about 92.4 parsecs (301 ly) away. It has a mass of about 0.857 ± 0.039 M☉. It is the host of two planets, HAT-P-17b and HAT-P-17c, both discovered in 2010. A search for a binary companion star using adaptive optics at the MMT Observatory was negative. A candidate companion was detected by a spectroscopic search of high-resolution K band infrared spectra taken at the Keck observatory.
HAT-P-27, also known as WASP-40, is the primary of a binary star system about 659 light-years away. It is a G-type main-sequence star. The star's age is similar to the Sun's at 4.4 billion years. HAT-P-27 is enriched in heavy elements, having a 195% concentration of iron compared to the Sun.
EQ Pegasi is a nearby binary system of two red dwarfs. Both components are flare stars, with spectral types of M4Ve and M6Ve respectively, and a current separation between the components of 5.8 arcseconds. The system is at a distance of 20.4 light-years, and is 950 million years old. The primary star is orbited by one known exoplanet.
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'.
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.
HAT-P-16 is a F-type main-sequence star about 725 light-years away. The star has a concentration of heavy elements slightly higher than solar abundance, and low starspot activity. The survey in 2015 have failed to find any stellar companions to it. The spectral analysis in 2014 have discovered the HAT-P-16 has a carbon to oxygen molar ratio of 0.58±0.08, close to Sun`s value of 0.55.
HAT-P-30, also known as WASP-51, is the primary of a binary star system about 700 light-years away. It is a G-type main-sequence star. HAT-P-30 has a similar concentration of heavy elements compared to the Sun.
WASP-72 is the primary of a binary star system. It is an F7 class dwarf star, with an internal structure just on the verge of the Kraft break. It is orbited by a planet WASP-72b. The age of WASP-72 is younger than the Sun at 3.55±0.82 billion years.
BD+00 316 is an ordinary star with a close-orbiting planetary companion in the equatorial constellation of Cetus. It is also known as WASP-71 since 2019; BD+00 316 is the stellar identifier from the Bonner Durchmusterung catalogue. With an apparent visual magnitude of 10.56, it is too faint to be visible to the naked eye. This star is located at a distance of 1,160 light-years based on parallax measurements, and is drifting further away with a heliocentric radial velocity of 7.7 km/s.
WASP-64 is a star about 1200 light-years away. It is a G7 class main-sequence star, orbited by a planet WASP-64b. It is younger than the Sun at 3.6±1.6 billion years, and it has a metal abundance similar to the Sun. The star is rotating rapidly, being spun up by the giant planet in a close orbit.
WASP-58 is a binary star system comprising a G-type main-sequence star and a red dwarf about 955 light-years away. WASP-58 is slightly depleted in heavy elements, having 80% of the solar abundance of iron. WASP-58 is much older than the Sun at 12.80+0.20
−2.10 billion years.
WASP-84, also known as BD+02 2056, is a G-type main-sequence star 327 light-years away in the constellation Hydra. Its surface temperature is 5350±31 K and is slightly enriched in heavy elements compared to the Sun, with a metallicity Fe/H index of 0.05±0.02. It is rich in carbon and depleted of oxygen. WASP-84's age is probably older than the Sun at 8.5+4.1
−5.5 billion years. The star appears to have an anomalously small radius, which can be explained by the unusually high helium fraction or by it being very young.
Kepler-410 is a binary star system. Its primary star, also known as Kepler-410A, is a F-type subgiant star, orbited by the orange dwarf star Kepler-410B on a wide orbit. The companion star was discovered in 2012.
WASP-80 is a K-type main-sequence star about 162 light-years away from Earth. The star's age is much younger than the Sun's at 1.352±0.222 billion years. WASP-80 could be similar to the Sun in concentration of heavy elements, although this measurement is highly uncertain.
HR 4098, also known as HD 90508, is a binary star system in the northern constellation of Ursa Major at a distance of 75 light years. This object is barely visible to the naked eye as a dim, yellow star with an apparent visual magnitude of 6.45. It is approaching the Earth with a heliocentric radial velocity of 7.2±0.2 km/s.