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 | |
Primary | G 9-38A |
Companion | G 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 | |
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 | |
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] The system has a very high stellar flare activity, with average five flares per hour. [1]
In 2015, the search for third star in the system has yielded inconclusive results. [13]
HD 114729 is a Sun-like star with an orbiting exoplanet in the southern constellation of Centaurus. Based on parallax measurements, it is located at a distance of 124 light years from the Sun. It is near the lower limit of visibility to the naked eye, having an apparent visual magnitude of 6.68 The system is drifting further away with a heliocentric radial velocity of 26.3 km/s. The system has a relatively high proper motion, traversing the celestial sphere at an angular rate of 0.373″·yr−1.
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.
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.
Xi Scorpii is part of a quintuple star system in the constellation Scorpius. It was assigned this designation by Bayer, although Ptolemy had catalogued the star in Libra. Flamsteed assigned it the designation 51 Librae, but this has fallen out of use since modern constellation boundaries assign the star to Scorpius.
HD 14412 is a single star in the southern constellation of Fornax. It has the Gould designation 22 G. Fornacis, while HD 14412 is the Henry Draper Catalogue designation. The star has an apparent visual magnitude of 6.33, which, according to the Bortle scale, can be dimly seen with the naked eye from rural locations. Based upon an annual parallax shift of 77.9″, this system is 42 light-years distant from the Sun. It is drifting further away with a radial velocity of +7.5 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.
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.
Gliese 445 is an M-type main sequence star in the northern part of the constellation Camelopardalis.
HAT-P-4 is a wide binary star consisting of a pair of G-type main-sequence stars in the constellation of Boötes. It is also designated BD+36°2593.
HIP 12961 is a star with an exoplanetary companion in the equatorial constellation of Eridanus. It is too faint to be visible to the naked eye, with an apparent visual magnitude of 10.24. The distance to this system can be estimated from its parallax measurements, which yield a separation of 76.3 light-years from the Sun. It is receding with a radial velocity of +33 km/s and has a high proper motion, traversing the celestial sphere at an angular rate of 0.300″ yr−1.
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.
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.
HD 106515 is a binary star in the constellation of Virgo.
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).
Gliese 880 is a red dwarf star in the northern constellation of Pegasus that may host an exoplanetary companion. No stellar companions to Gliese 880 have been discovered as of 2020.
GL Virginis, also known as G 12-30, is a star in the constellation of Virgo. It is a faint red dwarf, like more than 70% of the stars located within 10 parsecs of the Solar System; its magnitude visual magnitude is 13.898, making it impossible to see with the naked eye.
Gliese 49 is a star in the northern constellation of Cassiopeia. Visually, it is located 106 arcminutes north of the bright star γ Cassiopeiae. With an apparent visual magnitude of 9.56, it is not observable with the naked eye. It is located, based on the reduction of parallax data of Gaia, 32.1 light-years away from the Solar System. The star is drifting closer to the Sun with a radial velocity of −6 km/s.