Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Cassiopeia |
Right ascension | 02h 49m 44.4867s [1] |
Declination | +71° 45′ 11.6322″ [1] |
Apparent magnitude (V) | 8.17 [2] |
Characteristics | |
Spectral type | G0IV [3] |
Apparent magnitude (B) | 8.76 [2] |
Apparent magnitude (V) | 8.17 [2] |
Astrometry | |
Radial velocity (Rv) | −3.15 ± 0.20 [4] km/s |
Proper motion (μ) | RA: 90.982±0.064 [1] mas/yr Dec.: −33.197±0.062 [1] mas/yr |
Parallax (π) | 12.7776 ± 0.0389 mas [1] |
Distance | 255.3 ± 0.8 ly (78.3 ± 0.2 pc) |
Absolute magnitude (MV) | 3.70 |
Details | |
Mass | 1.275 ± 0.018 [5] M☉ |
Radius | 1.5007 ± 0.0076 [5] R☉ |
Temperature | 6079 ± 80 [6] K |
Metallicity [Fe/H] | 0.24 ± 0.05 [6] dex |
Age | 3.37 +0.20 −0.47 [5] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Extrasolar Planets Encyclopaedia | data |
HD 17156, named Nushagak by the IAU, [7] 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. [2] A search for a binary companion star using adaptive optics at the MMT Observatory was negative. [8]
The star is more massive and larger than the Sun while Its absolute magnitude of 3.70 and spectral type of G0, show that it is both hotter and more luminous. Based on asteroseismic density constraints and stellar isochrones, it was found that the age is 3.37 +0.20
−0.47 billion years making it about two thirds as old as the Sun. Spectral observations show that the star is metal-rich. [3] [5]
An extrasolar planet, HD 17156 b, was discovered with the radial velocity method in 2007, and subsequently was observed to transit the star. At the time it was the transiting planet with the longest period. [3] [9]
The star was given the name Nushagak by the IAU, chosen by United States representatives for the NameExoWorlds content, with the comment that "Nushagak is a regional river near Dilingham, Alaska, which is famous for its wild salmon that sustain local Indigenous communities." [7] HD 17156 b was given the designation Mulchatna, as Mulchatna is a tributary of the Nushagak river.
It is the first star in Cassiopeia around which an orbiting planet was discovered (in 2007) using the radial velocity method. Later observations showed that this planet also transited the star. [9] In February 2008, a second planet was proposed, with a 5:1 mean motion resonance to the inner planet HD 17156 b, though in 2017 this planet candidate was retracted. [10]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b / Mulchatna | 3.235±0.032 MJ | 0.16278±0.00076 | 21.2163979 ± 0.0000159 | 0.6703+0.0014 −0.0013 | — | — |
HD 209458 is an 8th-magnitude star in the constellation Pegasus. It is a G0V star, and is thus very similar to the Sun. Because it is located at a distance of 157 light-years, it is not visible to the unaided eye. With good binoculars or a small telescope it should be easily detectable.
HD 169830 is a star in the southern constellation of Sagittarius. It has a yellow-white hue and is dimly visible to the naked eye with an apparent visual magnitude of +5.90. The star is located at a distance of 120 light years from the Sun based on parallax. It is drifting closer with a radial velocity of −17.3 km/s, and is predicted to come as close as 20.7 ly (6.4 pc) in 2.08 million years. HD 169830 is known to be orbited by two large Jupiter-like exoplanets.
HD 6434 is a star in the southern constellation of Phoenix. Yellow dwarfs such as this are not very luminous, so at a distance of 138 light years it is not visible to the unaided eye. However, with binoculars it is readily visible under ideal observing conditions, having an apparent visual magnitude of 7.71. The star is drifting further from the Sun with a radial velocity of +23 km/s.
HD 187123 is a single, yellow-hued star with two exoplanetary companions in the northern constellation of Cygnus. It has an apparent visual magnitude of 7.83, making it an 8th magnitude star that is too faint to be visible with the naked eye. However, it should be easy target with binoculars or small telescope. The system is located at a distance of 150 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −17 km/s.
HD 4208 is a star in the southern constellation of Sculptor. It has a yellow hue with an apparent visual magnitude of 7.78, making it too dim to be visible to the naked eye. But with binoculars or small telescope it should be an easy target. This object is located at a distance of 111.6 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +57 km/s.
HD 52265 is a 6th-magnitude G-type main sequence star located approximately 98 light-years away in the constellation of Monoceros. It is 21% more massive than and more than twice as luminous as the Sun. The age of the star is roughly 2.6 billion years. The star HD 52265 is named Citalá. The name was selected in the NameExoWorlds campaign by El Salvador, during the 100th anniversary of the IAU. Citalá means River of stars in the native Nahuat language.
HD 38529 is a binary star approximately 138 light-years away in the constellation of Orion.
HD 1237 is a binary star system approximately 57 light-years away in the constellation of Hydrus.
HD 80606 and HD 80607 are two stars comprising a binary star system. They are approximately 217 light-years away in the constellation of Ursa Major. Both stars orbit each other at an average distance of 1,200 astronomical units. The binary system is listed as Σ1341 in the Struve Catalogue of Double Stars; however, this designation is not in wide use and the system is usually referred to by the HD designations of its constituent stars. An extrasolar planet has been confirmed to orbit HD 80606 in a highly elliptical orbit.
HD 224693, also named Axólotl, is a star in the equatorial constellation of Cetus, and is positioned near the western constellation border with Aquarius. It can be viewed with a small telescope but is too faint to be seen with the naked eye, having an apparent visual magnitude of 8.23. Based on parallax measurements, the object is located at a distance of approximately 306 light years from the Sun. It is drifting further away with a radial velocity of 1.5 km/s.
HD 175541 is an 8th magnitude star with an exoplanetary companion in the constellation Serpens. It has the proper name Kaveh, which was selected by Iran during the NameExoWorlds campaign as part of the 100th anniversary of the IAU. Kaveh is one of the heroes of Shahnameh. The apparent visual magnitude of 8.02 is too faint for this star to be visible in the naked eye. It is located at a distance of approximately 424 light years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of +20 km/s. Despite its distance, it was given the number 736 in the Gliese Catalogue of Nearby Stars.
HD 118203 is a star located in the northern circumpolar constellation of Ursa Major. It has the proper name Liesma, which means flame, and it is the name of a character from the Latvian poem Staburags un Liesma. The name was selected in the NameExoWorlds campaign by Latvia, during the 100th anniversary of the IAU.
HD 162020 is a star in the southern constellation of Scorpius with a likely red dwarf companion. It has an apparent visual magnitude of 9.10, which is too faint to be visible to the naked eye. The distance to this system is 101 light years based on stellar parallax. It is drifting closer to the Sun with a radial velocity of −27 km/s, and is predicted to come to within ~18 light-years in 1.1 million years.
HD 45652 is a star with an exoplanetary companion in the equatorial constellation of Monoceros. It was officially named Lusitânia on 17 December 2019, after the IAU100 press conference in Paris by the IAU. This star has an apparent visual magnitude of 8.10, making it an 8th magnitude star that is too dim to be visible to the naked eye. The system is located at a distance of 114 light-years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −5 km/s. It shows a high proper motion, traversing the celestial sphere at an angular rate of 0.188 arcsec yr−1.
HD 102272 is a star in the equatorial constellation of Leo. With an apparent visual magnitude of 8.69, it is too faint to be visible to the naked eye. The syat is located at a distance of approximately 1,140 light years based on parallax measurements, but is drifting closer to the Sun with a radial velocity of −12 km/s. As of 2008, two extrasolar planets are known to orbit the star.
HD 17156 b, named Mulchatna by the IAU, is an extrasolar planet approximately 255 light-years away in the constellation of Cassiopeia. The planet was discovered orbiting the yellow subgiant star HD 17156 in April 2007. The planet is classified as a relatively cool hot Jupiter planet slightly smaller than Jupiter but slightly larger than Saturn. This highly-eccentric three-week orbit takes it approximately 0.0523 AU of the star at periastron before swinging out to approximately 0.2665 AU at apastron. Its eccentricity is about the same as 16 Cygni Bb, a so-called "eccentric Jupiter". Until 2009, HD 17156 b was the transiting planet with the longest orbital period.
HD 60532 is a white (F-type) main sequence star located approximately 84 light-years away in the constellation of Puppis, taking its primary name from its Henry Draper Catalogue designation. It is calculated to be 1.44 times more massive than the Sun. The star is only 59% as old as the Sun and has metallicity of only 38% that of the Sun. In 2008, two extrasolar planets were discovered in orbit around it.
HAT-P-8 is a magnitude 10 star located 700 light-years away in Pegasus. It is a F-type star about 28% more massive than the Sun. Two red dwarf companions have been detected around HAT-P-8. The first has a spectral type of M5V and has a mass of 0.22 M☉. The second is even less massive, at 0.18 M☉, and its spectral type is M6V.
BD−17 63 is a low-mass K type star in the southern constellation Cetus. It is a 9th magnitude star at a distance of 113 light years from Earth.
HD 85390 is a star with an exoplanet companion in the southern constellation of Vela. It was given the proper name Natasha by Zambia during the 100th anniversary of the IAU. Natasha means "thank you" in many languages of Zambia. This star is too faint to be seen with the naked eye, having an apparent visual magnitude of 8.54. It is located at a distance of 109 light years from the Sun based on parallax, and is drifting further away with a radial velocity of 33 km/s.
OUTDATED, REJECTED AND CANNOT BE PUBLISHED. DOES NOT INCLUDE VARIOUS ADVANCEMENTS IN THE FIELD (REPORTED IN OTHER PUBLICATIONS). NEED MORE DATA OBTAINED, AT WHICH POINT A COMPLETELY NEW PAPER WILL BE WRITTEN. PLEASE SCRAP
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