G 9-38

Last updated
GJ 1116
EICncLightCurve.png
An ultraviolet band light curve showing several flares on EI Cancri, adapted from Pettersen (1985) [1]
Observation data
Epoch J2000       Equinox J2000
Constellation Cancer
Right ascension 08h 58m 15.194s [2]
Declination +19° 45′ 47.08″ [2]
Apparent magnitude  (V)13.720 [3]
Characteristics
Spectral type M8Ve+M7V [4] [5]
Astrometry
G 9-38 A
Radial velocity (Rv)13 ± 5 [6]  km/s
Proper motion (μ)RA: −767.060±0.122 [7]   mas/yr
Dec.: −100.176±0.083 [7]   mas/yr
Parallax (π)194.1443 ± 0.1228  mas [7]
Distance 16.80 ± 0.01  ly
(5.151 ± 0.003  pc)
G 9-38 B
Proper motion (μ)RA: −937.133±0.190 [8]   mas/yr
Dec.: −34.559±0.138 [8]   mas/yr
Parallax (π)196.2619 ± 0.1976  mas [8]
Distance 16.62 ± 0.02  ly
(5.095 ± 0.005  pc)
Orbit
PrimaryG 9-38A
CompanionG 9-38B
Period (P)360 yr
Semi-major axis (a)33 AU
Details [9] [10]
G 9-38A
Mass 0.12  M☉
Luminosity (bolometric)0.000965  L☉
Temperature 2896±18  K
Metallicity [Fe/H]-0.12(unreliable)  dex
G 9-38B
Mass 0.10  M☉
Luminosity (bolometric)0.000992  L☉
Other designations
EI Cnc, GJ  1116, WDS J08582+1945AB, G 9-38, G 47-14, G 41-11, LP  426-40, LTT  12343, PLX  2144.03, GSC  01397-01138, 2MASS J08581519+1945470
A: Gaia DR2  660597997696173440, LHS  2076 [4] , NLTT  20638 [4]
B: Gaia DR2  660597997697274752, LHS  2077 [5] , NLTT  20637 [5]
Database references
SIMBAD The system
A
B
Cancer constellation map.svg
Red pog.png
G 9-38
Location of G 9-38 in the constellation Cancer

G 9-38, also known as EI Cancri and GJ 1116, is a binary star system consisting of two M-type stars. [11] At 16.7 light-years from the Sun, the system is relatively nearby. [12]

In 1985, Bjørn Ragnvald Pettersen announced his discovery that the star shows very high stellar flare activity, with an average of five flares per hour. [1] It was given its variable star designation, EI Cancri, in 1987. [13]

In 2015, the search for third star in the system has yielded inconclusive results. [14]

Related Research Articles

<span class="mw-page-title-main">Beta Cancri</span> Star in the constellation Cancer

Beta Cancri, also named Tarf, is the brightest star in the zodiacal constellation of Cancer. It has an apparent visual magnitude of +3.5 and an absolute magnitude of −1.2. Based on parallax measurements obtained during the Hipparcos mission, it is approximately 290 light-years distant from the Sun. An exoplanet, designated Beta Cancri b, is believed to be orbiting the star.

<span class="mw-page-title-main">DX Cancri</span> Red dwarf star in the constellation Cancer

DX Cancri is a variable star in the northern zodiac constellation of Cancer. With an apparent visual magnitude of 14.81, it is much too faint to be seen with the naked eye. Visually viewing this star requires a telescope with a minimum aperture of 16 in (41 cm). Based upon parallax measurements, DX Cancri is located at a distance of 11.8 light-years from Earth. This makes it the 18th closest star to the Sun. It is a proposed member of the Castor Moving Group of stars that share a common trajectory through space. This group has an estimated age of 200 million years.

<span class="mw-page-title-main">Omicron Tauri</span> Star in the constellation Taurus

ο Tauri, Latinized as Omicron Tauri, is a binary star system in the constellation Taurus, near the constellation border with Cetus. It has a yellow hue and is visible to the naked eye with an apparent visual magnitude of 3.61. It is approximately 270 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −20 km/s. As the westernmost bright point of light in Taurus, this system has the Flamsteed designation 1 Tauri; Omicron Tauri is the Bayer designation.

Upsilon2 Cancri is a faint, yellow-hued star in the zodiac constellation of Cancer. It is near the lower brightness limit of stars that can be viewed with the naked eye, having an apparent visual magnitude of +6.35. Based upon an annual parallax shift of 5.1325 mas as seen from our orbit, this system is roughly 635 light-years away.

Mu<sup>1</sup> Cancri Red giant star in the constellation Cancer

Mu1 Cancri, Latinised from μ1 Cancri, is a variable star in the zodiac constellation of Cancer. The name Mu1 comes from the Bayer naming system: the "1" in the name is because (from Earth) it appears to be close to 10 Cancri, or Mu2 Cancri. It is also known by the variable star designation BL Cancri. The star is dimly visible to the naked eye with an apparent visual magnitude that ranges from 5.87 down to 6.07. Parallax measurements put it about 630 light-years (192 parsecs) from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.28. The position of the star near the ecliptic means it is subject to lunar occultations.

<span class="mw-page-title-main">53 Cancri</span> Red star in the constellation Cancer

53 Cancri is a variable star in the zodiac constellation Cancer, located around 960 light years from the Sun. It has the variable star designation BO Cancri; 53 Cancri is the Flamsteed designation. This object is a challenge to view with the naked eye, having an apparent visual magnitude around 6. It is around 960 light years away.

<span class="mw-page-title-main">GJ 1245</span> Triple star system in the constellation Cygnus

GJ 1245 is a double star with components G 208-44 and G 208-45, located 15.2 light-years away in the constellation Cygnus. G 208-44 is itself a closer double star made up of two red dwarfs, while G 208-45 is also a red dwarf. GJ 1245 is the 43rd closest stellar system to the Solar System. GJ 1245 A and B are active flare stars, and the pair are collectively designated V1581 Cygni.

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.

HD 115404 is a binary star system located in the constellation Coma Berenices. Parallax measurements made by Hipparcos put the system at 36 light-years, or 11 parsecs, away. The combined apparent magnitude of the system is 6.52, with the magnitudes of the components being 6.66 and 9.50.

GJ 3379 is the nearest star in the Orion constellation, located at a distance of 17 light years from the Sun based on parallax. It is a single star with an apparent visual magnitude of +11.31 and an absolute magnitude of +12.71, therefore, the star is not visible with the naked eye. It is positioned in the upper left part of the Orion constellation, to the SSE of Betelgeuse. This star is drifting further away with a radial velocity of +30.0 kilometers per second. In the past, this star had a relatively close encounter with the Solar System. Some 161,000±6,000 years ago, it achieved a minimum distance of 4.08 ± 0.20 ly (1.25 ± 0.06 pc).

ADS 48 is a multiple star system in the constellation of Andromeda consisting of 7 stars. The components, in order from A to G, have apparent visual magnitudes of 8.826, 8.995, 13.30, 12.53, 11.68, 9.949, and 13.00.

<span class="mw-page-title-main">Stein 2051</span> Star in the constellation Camelopardalis

Stein 2051 is a nearby binary star system, containing a red dwarf and a degenerate star, located in constellation Camelopardalis at about 18 ly from Earth.

μ Cygni, Latinised as Mu Cygni, is a binary star system in the northern constellation of Cygnus. It is visible to the naked eye as a faint point of light with a combined apparent visual magnitude of 4.49. The system is located 72 light years distant from the Sun, based on parallax, and is drifting further away with a radial velocity of +17 km/s.

K2-3, also known as EPIC 201367065, is a red dwarf star with three known planets. It is on the borderline of being a late orange dwarf/K-type star, but because of its temperature, it is classified as a red dwarf.

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.

LHS 2090 is a red dwarf star of spectral type M6.5V, located in constellation Cancer at 20.8 light-years from Earth.

Gliese 829 is a double-lined spectroscopic binary system of two red dwarf stars in the constellation of Pegasus. They have a high proper motion of 1.08 arc seconds per year along a position angle of +69.58°. Based upon parallax measurements, the stars are at a distance of about 22 light years from the Sun. The system will make its closest approach to the Sun around 91,000 years from now when it achieves a perihelion distance of 17.65 ly (5.410 pc).

<span class="mw-page-title-main">FF Andromedae</span> Star in the constellation Andromeda

FF Andromedae is a spectroscopic binary in the constellation Andromeda. It has a typical apparent visual magnitude of 10.4, but undergoes flare events that can increase its brightness by about a magnitude.

References

  1. 1 2 Pettersen, B. R. (July 1985). "Discovery of flare activity on the low luminosity red dwarf system G9-38 AB". Astronomy & Astrophysics. 148: 151–154. Bibcode:1985A&A...148..151P . Retrieved 11 November 2021.
  2. 1 2 Cutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues. 2246: II/246. Bibcode:2003yCat.2246....0C.
  3. ↑ Zacharias, N. (2012). "The fourth US Naval Observatory CCD Astrograph Catalog (UCAC4)". VizieR On-line Data Catalog. Bibcode:2012yCat.1322....0Z.
  4. 1 2 3 "G9-38A". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 29 September 2020.
  5. 1 2 3 "G9-38B". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 29 September 2020.
  6. ↑ "G9-38". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 29 September 2020.
  7. 1 2 3 Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics . 649: A1. arXiv: 2012.01533 . Bibcode:2021A&A...649A...1G. doi: 10.1051/0004-6361/202039657 . S2CID   227254300. (Erratum:  doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  8. 1 2 3 Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics . 649: A1. arXiv: 2012.01533 . Bibcode:2021A&A...649A...1G. doi: 10.1051/0004-6361/202039657 . S2CID   227254300. (Erratum:  doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  9. ↑ Rojas-Ayala, Bárbara; Covey, Kevin R.; Muirhead, Philip S.; Lloyd, James P. (2011), "Metallicity and Temperature Indicators in M dwarf K band Spectra: Testing New & Updated Calibrations With Observations of 133 Solar Neighborhood M dwarfs", The Astrophysical Journal, 748 (2): 93, arXiv: 1112.4567 , Bibcode:2012ApJ...748...93R, doi:10.1088/0004-637X/748/2/93, S2CID   41902340
  10. ↑ Nearby Star Summary Table
  11. ↑ Vizier query: Name=G* 1116, Centre de Données astronomiques de Strasbourg, accessed 30 December 2012.
  12. ↑ Nearby Stars Catalog (NSC) Archived 2021-02-27 at the Wayback Machine , Planetary Habitability Laboratory, University of Puerto Rico at Arecibo accessed 31 December 2012.
  13. ↑ Kholopov, P. N.; Samus, N. N.; Kazarovets, E. V.; Kireeva, N. N. (August 1987). "The 68th Name-List of Variable Stars" (PDF). Information Bulletin on Variable Stars. 3058: 1–30. Bibcode:1987IBVS.3058....1K . Retrieved 1 January 2025.
  14. ↑ Davison, Cassy L.; White, R. J.; Henry, T. J.; Riedel, A. R.; Jao, W-C.; Bailey Iii, J. I.; Quinn, S. N.; Cantrell, J. R.; Subasavage, J. P.; Winters, J. G. (2015), "A 3D Search for Companions to 12 Nearby M-Dwarfs", The Astronomical Journal, 149 (3): 106, arXiv: 1501.05012 , Bibcode:2015AJ....149..106D, doi:10.1088/0004-6256/149/3/106, S2CID   9719725


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