Gliese 777

Last updated
Gliese 777
Observation data
Epoch J2000.0       Equinox J2000.0
Constellation Cygnus
Right ascension 20h 03m 37.405s [1]
Declination +29° 53′ 48.492″ [1]
Apparent magnitude  (V)+5.73 [2] / +14.40
Characteristics
Spectral type G6IV [2] / M4.5V
Astrometry
Radial velocity (Rv)−45.34±0.12 [1]  km/s
Proper motion (μ)RA: 683.196  mas/yr [1]
Dec.: -525.501  mas/yr [1]
Parallax (π)62.4865 ± 0.34  mas [1]
Distance 52.2 ± 0.3  ly
(16.00 ± 0.09  pc) [1]
Details [3]
Mass 0.93±0.02  M☉
Radius 1.142±0.009  R☉
Luminosity 1.114±0.007  L☉
Surface gravity (log g)4.292±0.012  cgs
Temperature 5,557±22  K
Metallicity [Fe/H]0.17±0.04  dex
Age 6.7 [2]   Gyr
Other designations
Gliese 777
HD 190360: BD+29°3872, Gliese 777 A, HIP 98767, HR 7670, LHS 3510.
G 125-55: Gliese 777 B, LHS 3509.
Database references
SIMBAD AB
A
B
Exoplanet Archive data
ARICNS data
data2

Gliese 777, often abbreviated as Gl 777 or GJ 777, is a binary star approximately 52 light-years away in the constellation of Cygnus. The system is also a binary star system made up of two stars and possibly a third. As of 2005, two extrasolar planets are known to orbit the primary star.

Contents

Stellar components

The primary star of the system (catalogued as Gliese 777 A) is a yellow subgiant, a Sun-like star that is ceasing fusing hydrogen in its core. The star is much older than the Sun, about 6.7 billion years old. It is 4% less massive than the Sun. It is also rather metal-rich, having about 70% more "metals" (elements heavier than helium) than the Sun, which is typical for stars with extrasolar planets.

The secondary star (Gliese 777 B) is a distant, dim red dwarf star orbiting the primary at a distance of 3,000 astronomical units (0.047 light years). One orbit takes at least tens of thousands of years to complete. The star itself may be a binary, the secondary being a very dim red dwarf. Not much information is available on the star system.

Planetary system

In 2002, a discovery of a long-period, wide-orbiting, planet (Gliese 777 b) was announced by the Geneva extrasolar planet search team. [4] The planet was estimated to orbit in a circular path with low orbital eccentricity, but that estimate was increased with later measurements (e=0.36). [5] Initially therefore, the planet was believed to be a true "Jupiter-twin" but was later redefined as being more like an "eccentric Jupiter", with a mass of at least 1.5 times Jupiter and about the same size. In 2021, the true mass of Gliese 777 Ab was measured via astrometry. [6]

In 2005, further observation of the star showed another amplitude with a period of 17.1 days. [5] The mass of this second planet (Gliese 777 c) was only 18 times more than Earth, or about the same as Neptune, indicating it was one of the smallest planets discovered at the time. It too was initially thought to be on a circular orbital path that with later measurements turned out to be not the case.

The HD 190360 (Gliese 777 A) planetary system [7] [6]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
c ≥0.0600 ± 0.0076  MJ 0.1304 ± 0.007517.1110 ± 0.00480.237 ± 0.082——
b 1.8 ± 0.2  MJ 3.9 ± 0.22,854 ± 130.340 ± 0.01880.2 ± 23.2° —

There was a METI message sent to Gliese 777. It was transmitted from Eurasia's largest radar, 70-meter Eupatoria Planetary Radar. The message was named Cosmic Call 1; it was sent on July 1, 1999, and it will arrive at Gliese 777 in April 2051. [8]

See also

Related Research Articles

<span class="mw-page-title-main">Gliese 570</span> Quaternary star system in the constellation Libra

Gliese 570 is a quaternary star system approximately 19 light-years away. The primary star is an orange dwarf star. The other secondary stars are themselves a binary system, two red dwarfs that orbit the primary star. A brown dwarf has been confirmed to be orbiting in the system. In 1998, an extrasolar planet was thought to orbit the primary star, but it was discounted in 2000.

<span class="mw-page-title-main">Gliese 876</span> Star in the constellation Aquarius

Gliese 876 is a red dwarf star 15.2 light-years away from Earth in the constellation of Aquarius. It is one of the closest known stars to the Sun confirmed to possess a planetary system with more than two planets, after GJ 1061, YZ Ceti, Tau Ceti, and Wolf 1061; as of 2018, four extrasolar planets have been found to orbit the star. The planetary system is also notable for the orbital properties of its planets. It is the only known system of orbital companions to exhibit a near-triple conjunction in the rare phenomenon of Laplace resonance. It is also the first extrasolar system around a normal star with measured coplanarity. While planets b and c are located in the system's habitable zone, they are giant planets believed to be analogous to Jupiter.

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 28185 is a yellow dwarf star similar to the Sun located 128 light-years away from Earth in the constellation Eridanus. The designation HD 28185 refers to its entry in the Henry Draper catalogue. The star is known to possess one long-period extrasolar planet.

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

<span class="mw-page-title-main">30 Arietis</span> Multiple star system in the constellation Aries

30 Arietis is a 6th-apparent-magnitude multiple star system in the constellation of Aries. 30 Arietis is the Flamsteed designation. 30 Arietis A and B are separated by 38.1″ or about 1,500 AU at a distance of 130 light years away. The main components of both systems are both binaries with a composite spectra belonging to F-type main-sequence stars, meaning they are fusing hydrogen in their cores. The 30 Arietis system is 910 million years old, one fifth the age of the Sun.

<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.

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

<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 70642 is a star with an exoplanetary companion in the southern constellation of Puppis. It has an apparent visual magnitude of +7.17, which is too dim to be readily visible to the naked eye. The system is located at a distance of 95.5 light-years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of +49.3 km/s. It came to within 55.3 ly of the Solar System some 329,000 years ago.

Pi Mensae, also known as HD 39091, is a G-dwarf star in the constellation of Mensa. This star has a high proper motion. The apparent magnitude is 5.67, which can be visible to the naked eye in exceptionally dark, clear skies. It is nearly 60 light-years away. The star is slightly larger than the Sun in terms of mass, size, luminosity, temperature and metallicity, and is about 730 million years younger. It hosts three known planets.

Gliese 849, or GJ 849, is a small, solitary star in the equatorial constellation of Aquarius. It has a reddish hue and is invisible to the naked eye with an apparent visual magnitude of 10.41. The distance to this star is 28.8 light-years based on parallax, but it is drifting closer to the Sun with a radial velocity of −15.3 km/s. It has a pair of confirmed gas giant companions.

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.

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.

Gliese 86 is a K-type main-sequence star approximately 35 light-years away in the constellation of Eridanus. It has been confirmed that a white dwarf orbits the primary star. In 1998 the European Southern Observatory announced that an extrasolar planet was orbiting the star.

<span class="mw-page-title-main">NN Serpentis</span> Eclipsing post-common envelope binary star system in the constellation Serpens

NN Serpentis is an eclipsing post-common envelope binary system approximately 1670 light-years away. The system comprises an eclipsing white dwarf and red dwarf. The two stars orbit each other every 0.13 days.

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.

HD 104067 is a star with a planetary system in the southern constellation of Corvus. It has an apparent visual magnitude of 7.92 which is too faint to be visible with the naked eye. The distance to this star is 66.4 light-years based on parallax. It is drifting further away with a radial velocity of +15 km/s.

<span class="mw-page-title-main">DP Leonis</span> Star system in the constellation Leo

DP Leonis is a binary star system in the equatorial constellation of Leo. It is a variable star that ranges in apparent visual magnitude from 17.5 down to 19. The system is located at a distance of approximately 990 light-years from the Sun based on parallax. It is a cataclysmic variable star of the AM Herculis-type also known as polars. The system comprises an eclipsing white dwarf and red dwarf in tight orbit and an extrasolar planet. This eclipsing variable was discovered by P. Biermann and associates in 1982 as the optical counterpart to the EINSTEIN X-ray source E1114+182.

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 Ligi, R.; et al. (February 2016), "Radii, masses, and ages of 18 bright stars using interferometry and new estimations of exoplanetary parameters", Astronomy & Astrophysics, 586: 23, arXiv: 1511.03197 , Bibcode:2016A&A...586A..94L, doi:10.1051/0004-6361/201527054, S2CID   15941645, A94.
  3. ↑ Karovicova, I.; White, T. R.; Nordlander, T.; Casagrande, L.; Ireland, M.; Huber, D. (13 September 2021). "Fundamental stellar parameters of benchmark stars from CHARA interferometry -- II. Dwarf stars". Astronomy & Astrophysics. 658: A47. arXiv: 2109.06203 . doi:10.1051/0004-6361/202141833. ISSN   0004-6361.
  4. ↑ Naef, D.; et al. (2003). "The ELODIE survey for northern extra-solar planets II. A Jovian planet on a long-period orbit around GJ 777 A". Astronomy and Astrophysics. 410 (3): 1051–1054. arXiv: astro-ph/0306586 . Bibcode:2003A&A...410.1051N. doi:10.1051/0004-6361:20031341. S2CID   14853884.
  5. 1 2 Vogt, Steven S.; et al. (2005). "Five New Multicomponent Planetary Systems" (PDF). The Astrophysical Journal. 632 (1): 638–658. Bibcode:2005ApJ...632..638V. doi:10.1086/432901. S2CID   16509245. Archived (PDF) from the original on 2018-07-22. Retrieved 2020-09-05.
  6. 1 2 Feng, Fabo; Butler, R Paul; Jones, Hugh R A.; Phillips, Mark W.; Vogt, Steven S.; Oppenheimer, Rebecca; Holden, Bradford; Burt, Jennifer; Boss, Alan P. (2021). "Optimized modelling of Gaia–Hipparcos astrometry for the detection of the smallest cold Jupiter and confirmation of seven low-mass companions". Monthly Notices of the Royal Astronomical Society. 507 (2): 2856–2868. arXiv: 2107.14056 . Bibcode:2021MNRAS.507.2856F. doi: 10.1093/mnras/stab2225 .
  7. ↑ Wright, J. T.; et al. (2009). "Ten New and Updated Multi-planet Systems, and a Survey of Exoplanetary Systems". The Astrophysical Journal. 693 (2): 1084–1099. arXiv: 0812.1582 . Bibcode:2009ApJ...693.1084W. doi:10.1088/0004-637X/693/2/1084. S2CID   18169921.
  8. ↑ (in Russian) http://www.cplire.ru/rus/ra&sr/VAK-2004.html Archived 2019-05-30 at the Wayback Machine
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.