HD 74156

Last updated
HD 74156
Observation data
Epoch J2000.0       Equinox J2000.0
Constellation Hydra
Right ascension 08h 42m 25.12195s [1]
Declination +04° 34′ 41.1457″ [1]
Apparent magnitude  (V)+7.614 [2]
Characteristics
Spectral type G0V
U−B color index  ?
B−V color index 0.581 [2]
V−R color index 0.4
R−I color index 0.2
Variable type “None”
Astrometry
Radial velocity (Rv)3.90±0.13 [1]  km/s
Proper motion (μ)RA: 24.666±0.025  mas/yr [1]
Dec.: −200.238±0.019  mas/yr [1]
Parallax (π)17.4242 ± 0.0247  mas [1]
Distance 187.2 ± 0.3  ly
(57.39 ± 0.08  pc)
Absolute magnitude  (MV)+3.57 ± 0.15
Details
Mass 1.24 [2]   M☉
Radius 1.64 ± 0.19 [2]   R☉
Luminosity (bolometric)3.037 ± 0.485 [2]   L☉
Surface gravity (log g)4.4 ± 0.15 [2]   cgs
Temperature 5960 ± 100 [2]   K
Metallicity [Fe/H]+0.13 [2]   dex
Rotational velocity (v sin i)4.3 [2]  km/s
Age 3.7 ± 0.4 [2]   Gyr
Other designations
HIP 42723, SAO 117040, BD+05 2035, 2MASS J08422511+0434411
Database references
SIMBAD data

HD 74156 is a yellow dwarf star (spectral type G0V) in the constellation of Hydra, 187 light years from the Solar System. [1] It is known to be orbited by two giant planets.

Contents

Star

This star is 24% more massive and 64% larger than the Sun. The total luminosity is 2.96 times that of the Sun and its temperature 5960 K. [2] The age of the star is estimated at 3.7 billion years, [2] with metallicity 1.35 times that of the Sun based on its abundance of iron.

Planetary system

In April 2001, two giant planets were announced orbiting the star. [3] [4] The first planet HD 74156 b orbits the star at a distance closer than Mercury is to the Sun, in an extremely eccentric orbit. The second planet HD 74156 c is a long-period, massive planet (at least 8 times the mass of Jupiter), which orbits the star in an elliptical orbit with a semimajor axis of 3.90 astronomical units. [2] In 2022, the inclination and true mass of HD 74156 c were measured via astrometry. [5]

The HD 74156 planetary system [6] [5]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b ≥1.778±0.020  MJ 0.2916±0.003351.6385±0.00150.6380±0.0061——
c 8.665+1.385
−0.470  MJ 		3.678+0.145
−0.159		2448.5±4.20.377±0.006120.162+7.601
−66.225 ° 		—

Claims of a third planet

Given the two-planet configuration of the system under the assumption that the orbits are coplanar and have masses equal to their minimum masses, an additional Saturn-mass planet would be stable in a region between 0.9 and 1.4 AU between the orbits of the two known planets. [7] Under the "packed planetary systems" hypothesis, which predicts that planetary systems form in such a way that the system could not support additional planets between the orbits of the existing ones, the gap would be expected to host a planet.

In September 2007, a third planet with a mass at least 0.396 Jupiter masses was announced to be orbiting between planets b and c with an eccentric orbit. [8] The planet, orbiting in a region of the planetary system previously known to be stable for additional planets, was seen as a confirmation of the "packed planetary systems" hypothesis. [9] However, Roman V. Baluev has cast doubt on this discovery, suggesting that the observed variations may be due to annual errors in the data. [10] A subsequent search using the Hobby-Eberly Telescope also failed to confirm the planet, [11] and further data obtained using HIRES instrument strongly contradicts its existence. [2]

See also

Related Research Articles

<span class="mw-page-title-main">HD 12661</span> Star in the constellation Aries

HD 12661 is a G-type main sequence star in the northern constellation of Aries. The star is slightly larger and more massive than the Sun, with an estimated age of seven billion years. It has two known extrasolar planets.

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.

83 Leonis, abbreviated 83 Leo, is a binary star system approximately 59 light-years away in the constellation of Leo. The primary star of the system is a cool orange subgiant star, while the secondary star is an orange dwarf star. The two stars are separated by at least 515 astronomical units from each other. Both stars are presumed to be cooler than the Sun.

HD 217107 is a yellow subgiant star approximately 65 light-years away from Earth in the constellation of Pisces. Its mass is very similar to the Sun's, although it is considerably older. Two planets have been discovered orbiting the star: one is extremely close and completes an orbit every seven days, while the other is much more distant, taking fourteen years to complete an orbit.

HD 177830 is a 7th magnitude binary star system located approximately 205 light-years away in the constellation of Lyra. The primary star is slightly more massive than the Sun, but cooler being a type K star. Therefore, it is a subgiant clearly more evolved than the Sun. In visual light it is four times brighter than the Sun, but because of its distance, about 204 light years, it is not visible to the unaided eye. With binoculars it should be easily visible.

HD 69830 is a yellow dwarf star located 41.0 light-years away in the constellation of Puppis. In 2005, the Spitzer Space Telescope discovered a narrow ring of warm debris orbiting the star. The debris ring contains substantially more dust than the Solar System's asteroid belt. In 2006, three extrasolar planets with minimum masses comparable to Neptune were confirmed in orbit around the star, located interior to the debris ring.

HD 38529 is a binary star approximately 138 light-years away in the constellation of Orion.

<span class="mw-page-title-main">HD 108874</span> Star in the constellation Coma Berenices

HD 108874 is a star with a pair of orbiting exoplanets in the northern constellation of Coma Berenices. It is located 194.5 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −30 km/s. The absolute magnitude of this star is 4.79, but at that distance the star has an apparent visual magnitude of 8.76, making it too faint to be visible to the naked eye. HD 108874 has a relatively large proper motion, traversing the celestial sphere at an angular rate of 0.157″ yr−1.

<span class="mw-page-title-main">HD 128311</span> Star in the constellation Boötes

HD 128311 is a variable star in the northern constellation of Boötes. It has the variable star designation HN Boötis, while HD 128311 is the star's designation in the Henry Draper Catalogue. The star is invisible to the naked eye with an apparent visual magnitude that fluctuates around 7.48. It is located at a distance of 53 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −9.6 km/s. Two confirmed extrasolar planets have been detected in orbit around this star.

HD 1237 is a binary star system approximately 57 light-years away in the constellation of Hydrus.

HD 102195 is an orange-hued star in the zodiac constellation of Virgo with a confirmed exoplanet companion. With an apparent visual magnitude of 8.07, the star is too faint to be seen with the naked eye. The distance to HD 102195 can be estimated from its annual parallax shift of 34.06 mas, yielding 95.8 light years. It is moving further away from the Earth with a heliocentric radial velocity of 1.85 km/s. This is a high proper motion star and a possible member of the η Cha stellar kinematic group.

HD 73526 is a star in the southern constellation of Vela. With an apparent visual magnitude of +8.99, it is much too faint to be viewed with the naked eye. The star is located at a distance of approximately 316 light-years from the Sun based on parallax, and is drifting further away with a radial velocity of +26 km/s. It is a member of the thin disk population.

<span class="mw-page-title-main">HD 80606 and HD 80607</span> Binary star system in the constellation Ursa Major

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 Struve 1341 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 155358 is a low metallicity yellow dwarf star approximately 43 pc away in the constellation Hercules. This star is known to be orbited by two extrasolar planets.

HD 11964 is a binary star system located 110 light-years away from the Sun in the equatorial constellation of Cetus. It is visible in binoculars or a telescope but is too faint to be seen with the naked eye, having an apparent visual magnitude of 7.51. The system is drifting closer to the Sun with a radial velocity of −9 km/s. Two extrasolar planets have been confirmed to orbit the primary.

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.

Gliese 317 is a small red dwarf star with two exoplanetary companions in the southern constellation of Pyxis. It is located at a distance of 49.6 light-years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of +87.8 km/s. This star is too faint to be viewed with the naked eye, having an apparent visual magnitude of 11.98 and an absolute magnitude of 11.06.

HD 114762 b is a small red dwarf star, in the HD 114762 system, formerly thought to be a massive gaseous extrasolar planet, approximately 126 light-years (38.6 pc) away in the constellation of Coma Berenices. This optically undetected companion to the late F-type main-sequence star HD 114762 was discovered in 1989 by Latham, et al., and confirmed in an October 1991 paper by Cochran, et al. It was thought to be the first discovered exoplanet

HD 5319 is an 8th magnitude star approximately 319 light years away in the constellation Cetus. It is a subgiant star of spectral type K3, having run out of hydrogen in its core. When it was main-sequence, the spectral type was early F or late A.

HD 175167 is a star with an exoplanet companion in the southern constellation of Pavo. It is too faint to be visible with the naked eye at an apparent visual magnitude of 8.01. The system is located at a distance of 232 light-years from the Sun based on parallax measurements, and it is drifting further away with a radial velocity of 5 km/s. It shows a high proper motion, traversing the celestial sphere at an angular rate of 0.190 arcsec yr−1.

References

  1. 1 2 3 4 5 6 7 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211 . Bibcode:2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940 . S2CID   244398875. Gaia DR3 record for this source at VizieR.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Meschiari, Stefano; et al. (2011). "The Lick-Carnegie Survey: Four New Exoplanet Candidates". The Astrophysical Journal. 727 (2). 117. arXiv: 1011.4068 . Bibcode:2011ApJ...727..117M. doi:10.1088/0004-637X/727/2/117. S2CID   59065004.
  3. ↑ "Exoplanets: The Hunt Continues!" (Press release). Garching, Germany: European Southern Observatory. April 4, 2001. Retrieved December 27, 2012.
  4. ↑ Naef, Dominique; Mayor, Michel; Beuzit, Jean-Luc; Perrier, Christian; Queloz, Didier; Sivan, Jean-Pierre; Udry, Stéphane (2004). "The ELODIE survey for northern extra-solar planets. III. Three planetary candidates detected with ELODIE" (PDF). Astronomy and Astrophysics . 414 (1): 351–359. arXiv: astro-ph/0310261 . Bibcode:2004A&A...414..351N. doi:10.1051/0004-6361:20034091. S2CID   16603563.
  5. 1 2 Feng, Fabo; Butler, R. Paul; et al. (August 2022). "3D Selection of 167 Substellar Companions to Nearby Stars". The Astrophysical Journal Supplement Series . 262 (21): 21. arXiv: 2208.12720 . Bibcode:2022ApJS..262...21F. doi: 10.3847/1538-4365/ac7e57 . S2CID   251864022.
  6. ↑ Feng, Y. Katherina; et al. (2015). "The California Planet Survey IV: A Planet Orbiting the Giant Star HD 145934 and Updates to Seven Systems with Long-period Planets". The Astrophysical Journal. 800 (1). 22. arXiv: 1501.00633 . Bibcode:2015ApJ...800...22F. doi:10.1088/0004-637X/800/1/22. S2CID   56390823.
  7. ↑ Sean N. Raymond; Rory Barnes (2005). "Predicting Planets in Known Extrasolar Planetary Systems. II. Testing for Saturn Mass Planets". The Astrophysical Journal. 619 (1): 549–557. arXiv: astro-ph/0404211 . Bibcode:2005ApJ...619..549R. doi:10.1086/426311. S2CID   13015545.
  8. ↑ Jacob L. Bean; et al. (2008). "Detection of a Third Planet in the HD 74156 System Using the Hobby-Eberly Telescope". The Astrophysical Journal. 672 (2): 1202–1208. arXiv: 0709.1656 . Bibcode:2008ApJ...672.1202B. doi:10.1086/523701. hdl:2152/35107. S2CID   15507937.
  9. ↑ Barnes, Rory; et al. (2008). "The Successful Prediction of the Extrasolar Planet HD 74156 d". The Astrophysical Journal Letters. 680 (1): L57–L60. arXiv: 0804.4496 . Bibcode:2008ApJ...680L..57B. doi:10.1086/589712. S2CID   14070540.
  10. ↑ Baluev, Roman V. (2008). "Accounting for velocity jitters in planet search surveys". Monthly Notices of the Royal Astronomical Society . 393 (3): 969–978. arXiv: 0712.3862 . Bibcode:2009MNRAS.393..969B. doi:10.1111/j.1365-2966.2008.14217.x. S2CID   15170720.
  11. ↑ Wittenmyer, Robert A.; Endl, Michael; Cochran, William D.; Levison, Harold F.; Henry, Gregory W. (2009). "A Search for Multi-Planet Systems Using the Hobby-Eberly Telescope". The Astrophysical Journal Supplement. 182 (1): 97–119. arXiv: 0903.0652 . Bibcode:2009ApJS..182...97W. doi:10.1088/0067-0049/182/1/97. S2CID   7422668.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.