Groombridge 34

Last updated
Groombridge 34
GXAndLightCurve.png
Ultraviolet band light curves for GX Andromedae, with flares marked by red arrows. Adapted from Pettersen and Griffin (1980) [1]
Observation data
Epoch J2000       Equinox J2000
Constellation Andromeda
Groombridge 34 A
Right ascension 00h 18m 22.88498s [2]
Declination +44° 01′ 22.6380″ [2]
Apparent magnitude  (V)8.119 [3]
Groombridge 34 B
Right ascension 00h 18m 25.82514s [4]
Declination +44° 01′ 38.0924″ [4]
Apparent magnitude  (V)11.007 [3]
Characteristics
Spectral type M1.4V + M4.1V [3]
U−B color index +1.24/+1.40 [5]
B−V color index +1.56/+1.80 [5]
Variable type Flare stars
Astrometry
Groombridge 34 A
Radial velocity (Rv)+11.62±0.08 [6]  km/s
Proper motion (μ)RA: 2,891.518  mas/yr [2]
Dec.: 411.832  mas/yr [2]
Parallax (π)280.7068 ± 0.0203  mas [2]
Distance 11.6191 ± 0.0008  ly
(3.5624 ± 0.0003  pc)
Groombridge 34 B
Radial velocity (Rv)10.60±0.15 [4]  km/s
Proper motion (μ)RA: 2,862.796  mas/yr [4]
Dec.: 336.432  mas/yr [4]
Parallax (π)280.6947 ± 0.0278  mas [4]
Distance 11.620 ± 0.001  ly
(3.5626 ± 0.0004  pc)
Orbit [7]
Period (P)1230+930
−110 yr
Semi-major axis (a)93+42
−6  AU
Eccentricity (e)0.53+0.23
−0.28
Inclination (i)54+11
−16°
Longitude of the node (Ω)2+35
−43°
Periastron epoch (T)7140+560
−140
Details
Groombridge 34 A
Mass 0.393+0.009
−0.008 [8]   M☉
Radius 0.385±0.002 [8]   R☉
Luminosity 0.02249±0.00019 [8]   L☉
Habitable zone inner limit0.112 [9]   AU
Habitable zone outer limit0.239 [9]  AU
Surface gravity (log g)4.87±0.04 [7]   cgs
Temperature 3,601+12
−11 [8]   K
Metallicity [Fe/H]−0.34±0.09 [7]   dex
Rotation 43.86±0.56 days [7]
Rotational velocity (v sin i)1.09±0.79 [7]  km/s
Age ~3.02 [3]   Gyr
Groombridge 34 B
Mass 0.15±0.02 [7]   M☉
Radius 0.18±0.03 [7]   R☉
Luminosity~8.5×10−4 [7]   L☉
Habitable zone inner limit0.048 [9]  AU
Habitable zone outer limit0.103 [9]  AU
Surface gravity (log g)5.08±0.15 [7]   cgs
Temperature 3304±70 [7]   K
Metallicity [Fe/H]−0.37±0.10 [3]   dex
Age ~2.754 [3]   Gyr
Other designations
GX/GQ Andromedae, BD+43° 44, GCTP 49, GJ 15 A/B, G 171-047/171-048, HD 1326, HIP  1475, LHS 3/4, LTT 10108/10109, SAO  36248, PPM  42798 [10]
Database references
SIMBAD GJ 15 A
GJ 15 Ab
GJ 15 B
ARICNS GJ 15 A
GJ 15 B
Andromeda constellation map.svg
Red pog.png
Groombridge 34
Location of Groombridge 34 in the constellation Andromeda

Groombridge 34 is a binary star system in the northern constellation of Andromeda. It was listed as entry number 34 in A Catalogue of Circumpolar Stars, published posthumously in 1838 by British astronomer Stephen Groombridge. [11] Based upon parallax measurements taken by the Gaia spacecraft, the system is located about 11.6 light-years (3.6 parsecs ) from the Sun. This positions the pair among the nearest stars to the Solar System.

Contents

Both components are small, dim red dwarf stars that are too faint to be seen with the naked eye. They orbit around their common barycenter in a fairly eccentric orbit with a separation of about 93 AU and a period of around 1,230 years. [7] Both stars exhibit random variation in luminosity due to flares and they have been given variable star designations: the brighter member Groombridge 34 A is designated GX And, while the smaller component is designated GQ And. [12]

The star system has a relatively high proper motion of 2.9  arc seconds per year, [13] and is moving away from the Solar System at a velocity of 11.6 km/s. [6] It achieved perihelion some 15,000 years ago when it came within 11 ly (3.5 pc) of the Sun. [13]

GX Andromedae

The more massive and luminous component of the pair has the variable star designation GX Andromedae. It is a main-sequence red dwarf star of spectral type M1.4 [3] that varies its brightness due to stellar flares. Gaia observations suggest a rotation period of 44 days and a magnetic activity cycle of roughly 9 years. [14]

GQ Andromedae

The smaller companion bears the variable star name GQ Andromedae. It is a red dwarf main sequence star that undergoes flare events like the primary; it has a spectral type M4.1, [3] so it also has a lower effective temperature.

Planetary system

In August 2014, a planet orbiting around Groombridge 34 A was reported. [15] The planet's existence was deduced from analysis of the radial velocities of the parent star by the Eta-Earth Survey using HIRES at Keck Observatory. At the time of its discovery, it was the sixth-nearest-known exoplanet.

Using the CARMENES spectrograph combined with the measurements of the HARPS and HIRES spectrographs, researchers failed to detect the purported Groombridge 34 Ab. However, they did propose that another planet (Groombridge 34 Ac, GJ 15 Ac) could be orbiting the parent star. [16]

This discrepancy was later reconciled with new HIRES observations, covering a longer span of time, where both planets were recovered, constraining their minimum mass to 3.03 MEarth for Groombridge 34 Ab and 36 MEarth for Groombridge Ac. Their orbital periods are 11.4 and approximately 7,600 days, respectively. To date, this is the fourth-closest confirmed multi-planet system to the Sun, hosting the longest-period Neptune-mass exoplanet discovered so far. [7]

The Groombridge 34 A planetary system [7]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b ≥3.03+0.46
−0.44  M🜨 		0.072+0.003
−0.004		11.4407+0.0017
−0.0016		0.094+0.091
−0.065		——
c ≥36+25
−18  M🜨 		5.4+1.0
−0.9		~7,6000.27+0.28
−0.19		——

See also

Related Research Articles

Groombridge 1618 is a star in the northern constellation Ursa Major. With an apparent visual magnitude of +6.6, it lies at or below the threshold of stars visible to the naked eye for an average observer. It is relatively close to Earth, at 15.89 light-years (4.87 pc). This is a main sequence star of spectral type K7.5 Ve, having just 67% of the Sun's mass.

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.

<span class="mw-page-title-main">Wolf 1061</span> Star in the constellation Ophiuchus

Wolf 1061 is an M-class red dwarf star located about 14.1 light-years away in the constellation Ophiuchus. It is the 36th-closest-known star system to the Sun and has a relatively high proper motion of 1.2 seconds of arc per year. Wolf 1061 does not have any unusual spectroscopic features.

TZ Arietis is a red dwarf in the northern constellation of Aries. With a normal apparent visual magnitude of 12.3, it is too faint to be seen by the naked eye, although it lies relatively close to the Sun at a distance of 14.6 light-years. It is a flare star, which means it can suddenly increase in brightness for short periods of time.

Gliese 674(GJ 674) is a small red dwarf star with an exoplanetary companion in the southern constellation of Ara. It is too faint to be visible to the naked eye, having an apparent visual magnitude of 9.38 and an absolute magnitude of 11.09. The system is located at a distance of 14.8 light-years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −2.9 km/s. It is a candidate member of the 200 million year old Castor stream of co-moving stars.

HD 4308 is a single star with an orbiting exoplanet in the southern constellation of Tucana. It has a yellow hue and is a challenge to view with the naked eye even under good seeing conditions, having an apparent visual magnitude of 6.54. This object is located at a distance of 72 light years, as determined from parallax measurements. It is a population II star and is considered to be a member of the thick disk. The star is receding from the Sun with a radial velocity of +95 km/s.

<span class="mw-page-title-main">AD Leonis</span> M-type star in the constellation Leo

AD Leonis (Gliese 388) is a red dwarf star. It is located relatively near the Sun, at a distance of 16.2 light-years, in the constellation Leo. AD Leonis is a main sequence star with a spectral classification of M3.5V. It is a flare star that undergoes random increases in luminosity.

<span class="mw-page-title-main">Gliese 105</span> Triple star system in the constellation Cetus

Gliese 105 is a triple star system in the constellation of Cetus. It is located relatively near the Sun at a distance of 23.6 light-years. Despite this, even the brightest component is barely visible with the unaided eye (see Bortle scale). No planets have yet been detected around any of the stars in this system.

HD 4628 is a main sequence star in the equatorial constellation of Pisces. It has a spectral classification of K2.5 V and an effective temperature of 5,055 K, giving it an orange-red hue with a slightly smaller mass and girth than the Sun. HD 4628 lies at a distance of approximately 24.3 light years from the Sun based on parallax. The apparent magnitude of 5.7 is just sufficient for this star to be viewed with the unaided eye. The star appears to be slightly older than the Sun—approximately 5.4 billion years in age. The surface activity is low and, based upon the detection of UV emission, it may have a relatively cool corona with a temperature of one million K.

94 Ceti is a trinary star system approximately 73 light-years away in the constellation Cetus.

HR 4458 is a binary star system in the equatorial constellation of Hydra. It has the Gould designation 289 G. Hydrae; HR 4458 is the Bright Star Catalogue designation. At a distance of 31.13 light years, it is the closest star system to the Solar System within this constellation. This object is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.97. It is moving closer to the Earth with a heliocentric radial velocity of −22 km/s.

Gliese 412 is a pair of stars that share a common proper motion through space and are thought to form a binary star system. The pair have an angular separation of 31.4″ at a position angle of 126.1°. They are located 15.8 light-years distant from the Sun in the constellation Ursa Major. Both components are relatively dim red dwarf stars.

Gliese 176 is a small star with an orbiting exoplanet in the constellation of Taurus. With an apparent visual magnitude of 9.95, it is too faint to be visible to the naked eye. It is located at a distance of 30.9 light years based on parallax measurements, and is drifting further away with a heliocentric radial velocity of 26.4 km/s.

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 102 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 87822 is a triple star in the northern constellation of Leo Minor. The inner pair orbit each other with a period of about 18 years.

Gliese 433 is a dim red dwarf star with multiple exoplanetary companions, located in the equatorial constellation of Hydra. The system is located at a distance of 29.6 light-years from the Sun based on parallax measurements, and it is receding with a radial velocity of +18 km/s. Based on its motion through space, this is an old disk star. It is too faint to be viewed with the naked eye, having an apparent visual magnitude of 9.81 and an absolute magnitude of 10.07.

Gliese 251, also known as HIP 33226 or HD 265866, is a star located about 18 light years away from the Solar System. Located in the constellation of Gemini, it is the nearest star in this constellation. It is located near the boundary with Auriga, 49 arcminutes away from the bright star Theta Geminorum; due to its apparent magnitude of +9.89 it cannot be observed with the naked eye. The closest star to Gliese 251 is QY Aurigae, which is located 3.5 light years away.

HD 219623 is a solitary star in the northern circumpolar constellation of Cassiopeia. HD 219623 is its Henry Draper Catalogue designation. It has an apparent visual magnitude of 5.59, which lies in the brightness range that is visible to the naked eye. According to the Bortle scale, it can be observed from dark suburban skies. Parallax measurements place it at an estimated distance of around 67.2 light years. It has a relatively high proper motion, advancing 262 mas per year across the celestial sphere.

References

  1. ↑ Pettersen, B. R.; Griffin, R. F. (December 1980). "Non-emission-line flare stars". The Observatory. 100: 198–202. Bibcode:1980Obs...100..198P . Retrieved 30 October 2022.
  2. 1 2 3 4 5 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.
  3. 1 2 3 4 5 6 7 8 Mann, Andrew W.; et al. (May 2015), "How to Constrain Your M Dwarf: Measuring Effective Temperature, Bolometric Luminosity, Mass, and Radius", The Astrophysical Journal, 804 (1): 38, arXiv: 1501.01635 , Bibcode:2015ApJ...804...64M, doi:10.1088/0004-637X/804/1/64, S2CID   19269312, 64.
  4. 1 2 3 4 5 6 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.
  5. 1 2 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD, Bibcode:1986EgUBV........0M.
  6. 1 2 Nidever, David L.; et al. (August 2002), "Radial Velocities for 889 Late-Type Stars", The Astrophysical Journal Supplement Series, 141 (2): 503–522, arXiv: astro-ph/0112477 , Bibcode:2002ApJS..141..503N, doi:10.1086/340570, S2CID   51814894.
  7. 1 2 3 4 5 6 7 8 9 10 11 12 13 Pinamonti, M.; Damasso, M.; Marzari, F.; Sozzetti, A.; Desidera, S.; Maldonado, J.; Scandariato, G.; Affer, L.; Lanza, A. F.; Bignamini, A.; Bonomo, A. S.; Borsa, F.; Claudi, R.; Cosentino, R.; Giacobbe, P.; González-Álvarez, E.; González Hernández, J. I.; Gratton, R.; Leto, G.; Malavolta, L.; Martinez Fiorenzano, A.; Micela, G.; Molinari, E.; Pagano, I.; Pedani, M.; Perger, M.; Piotto, G.; Rebolo, R.; Ribas, I.; et al. (2018). "The HADES RV Programme with HARPS-N at TNG. VIII. GJ15A: A multiple wide planetary system sculpted by binary interaction". Astronomy and Astrophysics. 617: A104. arXiv: 1804.03476 . Bibcode:2018A&A...617A.104P. doi:10.1051/0004-6361/201732535. S2CID   54990041.
  8. 1 2 3 4 Pineda, J. Sebastian; Youngblood, Allison; France, Kevin (September 2021). "The M-dwarf Ultraviolet Spectroscopic Sample. I. Determining Stellar Parameters for Field Stars". The Astrophysical Journal. 918 (1): 23. arXiv: 2106.07656 . Bibcode:2021ApJ...918...40P. doi: 10.3847/1538-4357/ac0aea . S2CID   235435757. 40.
  9. 1 2 3 4 Cantrell, Justin R.; et al. (October 2013), "The Solar Neighborhood XXIX: The Habitable Real Estate of Our Nearest Stellar Neighbors", The Astronomical Journal, 146 (4): 99, arXiv: 1307.7038 , Bibcode:2013AJ....146...99C, doi:10.1088/0004-6256/146/4/99, S2CID   44208180.
  10. ↑ "V* GX And". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2016-02-09.{{cite web}}: CS1 maint: postscript (link)
  11. ↑ Groombridge, Stephen (1838), Airy, George Biddell (ed.), A Catalogue of Circumpolar Stars, J. Murray, p. 2.
  12. ↑ Petit, M. (October 1990), "Catalogue des étoiles variables ou suspectes dans le voisinage du Soleil", Astronomy and Astrophysics Supplement (in French), 85 (2): 971, Bibcode:1990A&AS...85..971P.
  13. 1 2 Bailer-Jones, C. A. L. (March 2015). "Close encounters of the stellar kind". Astronomy & Astrophysics. 575: 13. arXiv: 1412.3648 . Bibcode:2015A&A...575A..35B. doi:10.1051/0004-6361/201425221. S2CID   59039482. A35.
  14. ↑ Morris, Brett M.; Agol, Eric; Davenport, James R. A.; Hawley, Suzanne L. (2018). "Spotting stellar activity cycles in Gaia astrometry". Monthly Notices of the Royal Astronomical Society. 476 (4): 5408. arXiv: 1802.09943 . Bibcode:2018MNRAS.476.5408M. doi:10.1093/mnras/sty568. S2CID   73564680.
  15. ↑ Howard, Andrew W.; et al. (October 2014), "The NASA-UC-UH ETA-Earth Program. IV. A Low-mass Planet Orbiting an M Dwarf 3.6 PC from Earth", The Astrophysical Journal, 794 (1): 9, arXiv: 1408.5645 , Bibcode:2014ApJ...794...51H, doi:10.1088/0004-637X/794/1/51, S2CID   17361592, 51.
  16. ↑ Trifonov, Trifon; Kürster, Martin; Zechmeister, Mathias; Tal-Or, Lev; Caballero, José A.; Quirrenbach, Andreas; Amado, Pedro J.; Ribas, Ignasi; Reiners, Ansgar; et al. (2018). "The CARMENES search for exoplanets around M dwarfs. First visual-channel radial-velocity measurements and orbital parameter updates of seven M-dwarf planetary systems". Astronomy and Astrophysics. 609. A117. arXiv: 1710.01595 . Bibcode:2018A&A...609A.117T. doi:10.1051/0004-6361/201731442. S2CID   119340839.
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.