Gliese 900

Gliese 900

Gliese 900 imaged by WISE, with the planetary-mass companion circled
Observation data
Epoch J2000      Equinox J2000
Constellation Pisces[a]
Right ascension 23h 35m 00.27674s[1]
Declination +01° 36′ 19.4347″[1]
Apparent magnitude (V) 9.546[1]
Characteristics
A
Evolutionary stage Main sequence
Spectral type K5-7[2]
B−V color index 1.35[3]
B
Evolutionary stage Main sequence
Spectral type M3-4[2]
C
Evolutionary stage Main sequence
Spectral type M5-6[2]
Astrometry
Radial velocity (Rv)−10.44±0.44[4] km/s
Proper motion (μ) RA: 340.029 mas/yr[4]
Dec.: 28.456 mas/yr[4]
Parallax (π)47.9641 ± 0.0236 mas[4]
Distance68.00 ± 0.03 ly
(20.85 ± 0.01 pc)
Absolute magnitude (MV)7.95[b]
Details
A
Mass0.64 – 0.67[2] M☉
Radius0.716±0.021[5] R☉
Luminosity0.12±0.005[4] L☉
Temperature4,079±180[2] K
Metallicity [Fe/H]0.02[6] dex
Rotation11.9[7] days
Age200±50[7] Myr
B
Mass0.28 – 0.34[2] M☉
C
Mass0.16 – 0.24[2] M☉
Orbit
PrimaryA
CompanionBC
Period (P)≈80[2] yr
Orbit[6]
PrimaryB
CompanionC
Period (P)36 yr
Semi-major axis (a)444 mas (9.217 AU)[c]
Eccentricity (e)0.136
Inclination (i)82.21°
Argument of periastron (ω)
(secondary)		109.8°
Position (relative to A)[2]
Epoch of observationDecember 2006
Angular distance751 (A–B)
708 (A–C)
51 (B–C) mas
Position angle342.5 (A–B)
344.7 (A–C)
130.3 (B–C)°
Other designations
BD+00 5017, GJ 900, HIP 116384, WDS J23350+0136A,BC, G 29-47 / 157-46, LSPM J2235+0136, TIC 422618003, TYC 585-236-1, GSC 00585-00236, 2MASS J23350028+0136193, WISE J233500.50+013619.7
Database references
SIMBADdata
Exoplanet Archivedata

Gliese 900 (GJ 900, BD+00 5017) is a triple star system, located 68 light-years from Earth in the constellation Pisces. It is made up of three main sequence stars: one is a K-type star, the two others are M-dwarf stars. The two M-dwarfs form a binary system with a period of 36 years, and this system has a period of 80 years around the primary component. With an apparent magnitude of 9.546, Gliese 900 is not visible to the naked eye. A widely separated planet has been detected around the system.[7]

Stellar system

Location of Gliese 900 (circled)
Location of Gliese 900 (circled)

Gliese 900 is a hierarchical star system, made up of three main sequence stars: The primary component (Gliese 900 A) is a K5-K7 type star, that has 0.64–0.67 times the mass of the Sun,[2] 0.72 times its radius,[5] and 12% its luminosity.[4] A light curve from the Transiting Exoplanet Survey Satellite (TESS) shows that its rotational period is 12 days.[7] Gliese 900 A has a high level of chromospheric and coronal activity, although its apparent brightness presents little variation.[8] The other components are red dwarf stars. Gliese 900 B has a spectral type of M3–M4 and a mass between 0.24 and 0.34 solar masses. Gliese 900 C has a spectral type of M5–M6 and a mass between 0.16 and 0.24 solar masses.[2]

The system is young, about 200 million years old, and is a likely member (99.7% probability) of the nearby moving group Carina-Near.[9] It is a source of X-ray emission, with an observed flux of 9.13×102 mW M-2, and is also a source of ultraviolet emission.[7] The emission of X-rays is typical of young stars, and classifies it as one.[8] The TESS light curve identifies stellar flares on this star.[7]

Orbit

Gliese 900 B and C form an inner pair (named Gliese 900 BC) with an orbital period of around 36 years.[6] Gliese 900 BC and Gliese 900 A orbit the system's center of mass with a period of 80 years.[2][7] As of November 2004, B was separated from A by 751 milliarcseconds and C was separated from A by 708 mas. This separation changes over time.[2] It was identified as a multiple star system in 2002 by Eduardo L. Martín, using adaptive optics-corrected images at the 8.2 m Subaru Telescope. When first observed, the A–B and A–C separations were of 0.51 and 0.76 arcsecs respectively.[8] A further study by Malogolovets et al. (2007) identified this system as a hierarchical triple.[2]

Other stars in the system

Malogolovets et al. (2007) reported two other objects in 2MASS images (potentially late red dwarfs) that would be the components D and E and make the system quintuple, being "very likely" to be bound to the system.[2] However, these faint stars haven't been confirmed as members of the GJ 900 system, and are likely not associated.[7]

Motion

Gliese 900 is located 68 light-years from Earth, based on parallax measurements by the Gaia spacecraft.[4] The BP-RP spectra suggest a distance of 67.7 ly.[4] The space velocity components of this system are U = −28.7, V = −15 and W = 0.2.[10] Gliese 900 is part of the thin disk population of the Milky Way.[10][2] It was once classified as part of the IC 2602 supercluster.[8] A newer analysis using kinematics from the Gaia spacecraft suggest that Gliese 900 has a 99.7% chance of being a member of the Carina-Near moving group and a 0.3% chance of being a field star, i.e. not associated to any star cluster or stellar association.[7]

Planetary system

A 2024 study led by Austin Rothermich identified CWISE J233531.55+014219.6 (abbreviated to CW2335+0142) as a proper motion companion to Gliese 900, with 99.5% probability.[7] This object, also called Gliese 900 b or Gliese 900 (ABC)b,[11][12] is a planetary-mass object that has 10.5 times the mass of Jupiter (0.01 times the mass of the Sun), a spectral type T9[7] and a temperature of 500 K.[13] It was found to be at an angular separation of 587" from Gliese 900. At the estimated distance to this system, it translates to a projected separation of 12,000 astronomical units.[7]

As of 2024, Gliese 900 b has the largest observed separation of any known planet, and assuming a circular orbit, the longest orbital period.[14][15][d] The orbital period is estimated at 1.27[16] million years based on the projected separation. Due to the similar spectral type, orbital separation and age, CW2335+0142 has been compared to COCONUTS-2b by the discovery team.[7]

Also in 2024, a study using data from the Wide-field Infrared Survey Explorer found a red W2-W3 color, which the researchers interpret as a sign of low gravity for T-dwarfs. Low gravity is often seen as an indicator of a young age and a low mass.[13]

Gliese 900 planetary system[7]
Companion
(in order from star) 		Mass Projected separation
(AU) 		Orbital period (106 Myr) Eccentricity Inclination Radius
b 10.5 MJ 12,000 1.27[16]  –  – 1.11 RJ (estimate)[16]

See also

Notes

  1. ^ Obtained with a right ascension of 23h 35m 00.27674s and a declination of +01° 36′ 19.4347″[1] on this website.
  2. ^ Using the apparent magnitude and distance from Earth, Gliese 900's absolute magnitude can be calculated.
    9.546+5−5*log(20.85) = 7.95.
  3. ^ Using the angular separation and the parallax (both in milliarcseconds), the physical separation (in AU) can be obtained.
    444/48.17 = 9.217 AU.
  4. ^ Out of objects with a planetary mass (<13 MJ). Exoplanet databases list a few brown dwarfs at larger separations.

References

  1. ^ a b c d "GJ 900". SIMBAD. Centre de données astronomiques de Strasbourg.
  2. ^ a b c d e f g h i j k l m n o p Malogolovets, E. V.; Balega, Yu. Yu.; Rastegaev, D. A.; Hofmann, K. -H.; Weigelt, G. (2007-06-01). "GJ 900: A new hierarchical system with low-mass components". Astrophysical Bulletin. 62 (2): 117–124. arXiv:0707.2193. Bibcode:2007AstBu..62..117M. doi:10.1134/S1990341307020034.
  3. ^ Hünsch, M.; Schmitt, J. H. M. M.; Sterzik, M. F.; Voges, W. (1999-03-01). "The ROSAT all-sky survey catalogue of the nearby stars". Astronomy and Astrophysics Supplement Series. 135 (2): 319–338. Bibcode:1999A&AS..135..319H. doi:10.1051/aas:1999169. ISSN 0365-0138. Gliese 900's database entry at VizieR.
  4. ^ a b c d e f g 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. ^ a b Stassun, Keivan G.; Oelkers, Ryan J.; Paegert, Martin; Torres, Guillermo; Pepper, Joshua; De Lee, Nathan; Collins, Kevin; Latham, David W.; Muirhead, Philip S.; Chittidi, Jay; Rojas-Ayala, Bárbara; Fleming, Scott W.; Rose, Mark E.; Tenenbaum, Peter; Ting, Eric B. (2019-10-01). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. ISSN 0004-6256. Gliese 900's database entry at VizieR.
  6. ^ a b c Mann, Andrew W.; Dupuy, Trent; Kraus, Adam L.; Gaidos, Eric; Ansdell, Megan; Ireland, Michael; Rizzuto, Aaron C.; Hung, Chao-Ling; Dittmann, Jason; Factor, Samuel; Feiden, Gregory; Martinez, Raquel A.; Ruíz-Rodríguez, Dary; Thao, Pa Chia (2019-01-01). "How to Constrain Your M Dwarf. II. The Mass-Luminosity-Metallicity Relation from 0.075 to 0.70 Solar Masses". The Astrophysical Journal. 871 (1): 63. arXiv:1811.06938. Bibcode:2019ApJ...871...63M. doi:10.3847/1538-4357/aaf3bc. ISSN 0004-637X. Gliese 900 BC's database entry at VizieR.
  7. ^ a b c d e f g h i j k l m n Rothermich, Austin; Faherty, Jacqueline K.; Bardalez-Gagliuffi, Daniella; Schneider, Adam C.; Kirkpatrick, J. Davy; Meisner, Aaron M.; Burgasser, Adam J.; Kuchner, Marc; Allers, Katelyn; Gagné, Jonathan; Caselden, Dan; Calamari, Emily; Popinchalk, Mark; Suárez, Genaro; Gerasimov, Roman (2024-06-01). "89 New Ultracool Dwarf Comoving Companions Identified with the Backyard Worlds: Planet 9 Citizen Science Project". The Astronomical Journal. 167 (6): 253. arXiv:2403.04592. Bibcode:2024AJ....167..253R. doi:10.3847/1538-3881/ad324e. ISSN 0004-6256.
  8. ^ a b c d Martín, Eduardo L. (2003-08-01). "A New Multiple Stellar System in the Solar Neighborhood". The Astronomical Journal. 126 (2): 918–920. arXiv:astro-ph/0305289. Bibcode:2003AJ....126..918M. doi:10.1086/376742. ISSN 0004-6256.
  9. ^ Zuckerman, B.; Bessell, M. S.; Song, Inseok; Kim, S. (2006-10-01). "The Carina-Near Moving Group". The Astrophysical Journal. 649 (2): L115 – L118. arXiv:astro-ph/0609041. Bibcode:2006ApJ...649L.115Z. doi:10.1086/508060. ISSN 0004-637X.
  10. ^ a b Hinkel, Natalie R.; Mamajek, Eric E.; Turnbull, Margaret C.; Osby, Ella; Shkolnik, Evgenya L.; Smith, Graeme H.; Klimasewski, Alexis; Somers, Garrett; Desch, Steven J. (2017-10-01). "A Catalog of Stellar Unified Properties (CATSUP) for 951 FGK-Stars within 30 pc". The Astrophysical Journal. 848 (1): 34. arXiv:1709.04465. Bibcode:2017ApJ...848...34H. doi:10.3847/1538-4357/aa8b0f. ISSN 0004-637X. Gliese 900's database entry at VizieR.
  11. ^ "GJ 900 Overview". NASA Exoplanet Archive. Retrieved June 17, 2024.
  12. ^ "The Extrasolar Planet Encyclopaedia — GJ 900 (ABC)b". Extrasolar Planets Encyclopaedia. Paris Observatory.
  13. ^ a b Leggett, S. K.; Tremblin, Pascal (5 Nov 2024). "Redshifting the Study of Cold Brown Dwarfs and Exoplanets: the Mid-Infrared Wavelength Region as an Indicator of Surface Gravity and Mass". arXiv:2411.03549 [astro-ph].
  14. ^ Martin, Pierre-Yves (1995). "Catalogue of Exoplanets". exoplanet.eu. Retrieved 2024-06-20.
  15. ^ "Planetary Systems Composite Data". NASA Exoplanet Archive. Retrieved 25 June 2024.
  16. ^ a b c "GJ 900 b - NASA Science". science.nasa.gov. Retrieved 2024-06-20.