HD 17156

Last updated
HD 17156 / Nushagak
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
Nushagak, BD+71°171, HIP  13192, SAO  4737, GSC 04321-01320, PPM 5099, TYC 4321-1320-1, AG+71 95 [2]
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]

Contents

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]

Name

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.

Planetary system

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]

The HD 17156 planetary system [5] [11] [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±0.0007621.2163979 ± 0.00001590.6703+0.0014
−0.0013

See also

Related Research Articles

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<span class="mw-page-title-main">HD 17156 b</span> Extrasolar planet in the constellation of Cassiopeia

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.

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References

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  4. Barbieri, M.; et al. (2009). "Characterization of the HD 17156 planetary system". Astronomy and Astrophysics. 503 (2): 601–612. arXiv: 0812.0785 . Bibcode:2009A&A...503..601B. doi:10.1051/0004-6361/200811466. S2CID   3762143.
  5. 1 2 3 4 5 Nutzman, Philip; et al. (2011). "Precise Estimates of the Physical Parameters for the Exoplanet System HD 17156 Enabled by Hubble Space Telescope Fine Guidance Sensor Transit and Asteroseismic Observations". The Astrophysical Journal. 726 (1). 3. arXiv: 1011.0440 . Bibcode:2011ApJ...726....3N. doi:10.1088/0004-637X/726/1/3. S2CID   118003582.
  6. 1 2 Winn, Joshua N.; et al. (2009). "The Transit Light Curve Project. X. A Christmas Transit of HD 17156b". The Astrophysical Journal. 693 (1): 794–803. arXiv: 0810.4725 . Bibcode:2009ApJ...693..794W. doi:10.1088/0004-637X/693/1/794. S2CID   13894861.
  7. 1 2 "Approved names (§ United States of America)". Name Exo Worlds. IAU . Retrieved 19 December 2019.
  8. Adams, E. R.; et al. (2013). "Adaptive Optics Images. II. 12 Kepler Objects of Interest and 15 Confirmed Transiting Planets". The Astronomical Journal. 146 (1). 9. arXiv: 1305.6548 . Bibcode:2013AJ....146....9A. doi:10.1088/0004-6256/146/1/9. S2CID   119117620.
  9. 1 2 Barbieri, M.; et al. (2007). "HD 17156b: A Transiting Planet with a 21.2 Day Period and an Eccentric Orbit". Astronomy and Astrophysics Letters. 476 (2): L13–L16. arXiv: 0710.0898 . Bibcode:2007A&A...476L..13B. doi:10.1051/0004-6361:20078787. S2CID   14430349.
  10. 1 2 Short, Donald; et al. (2008). "Orbital Dynamics Of A Possible Second Planet In HD 17156". arXiv: 0803.2935 . Bibcode:2008arXiv0803.2935S. 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{{cite journal}}: Cite journal requires |journal= (help)
  11. Bonomo, A. S.; et al. (2017). "The GAPS Programme with HARPS-N at TNG . XIV. Investigating giant planet migration history via improved eccentricity and mass determination for 231 transiting planets". Astronomy and Astrophysics. 602. A107. arXiv: 1704.00373 . Bibcode:2017A&A...602A.107B. doi:10.1051/0004-6361/201629882. S2CID   118923163.