Gliese 900

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Gliese 900
Pisces constellation map.svg
Red circle.svg
Location on Gliese 900 (circled in red)
Observation data
Epoch J2000       Equinox J2000
Constellation Pisces [1]
Right ascension 23h 35m 00.27674s [2]
Declination +01° 36 19.4347 [2]
Apparent magnitude  (V)9.546 [3]
Characteristics
A
Evolutionary stage Main sequence [2]
Spectral type K5-7 [4]
B−V color index 1.35 [5]
B
Evolutionary stage Main sequence [4]
Spectral type M3-4 [4]
C
Evolutionary stage Main sequence [4]
Spectral type M5-6 [4]
Astrometry
Radial velocity (Rv)−10.44±0.44 [2] km/s
Proper motion (μ)RA: 340.029 mas/yr [2]
Dec.: 28.456 mas/yr [2]
Parallax (π)47.9641±0.0236  mas [2]
Distance 68.00 ± 0.03  ly
(20.85 ± 0.01  pc)
Absolute magnitude  (MV)7.95 [a]
Details
A
Mass 0.64 0.67 [4]   M
Radius 0.716±0.021 [6]   R
Luminosity 0.12±0.005 [2]   L
Temperature 4,079±180 [4]   K
Metallicity [Fe/H]0.02 [7]   dex
Rotation 11.9 [8] days
Age 200±50 [8]   Myr
B
Mass 0.28 0.34 [4]   M
C
Mass 0.16 0.24 [4]   M
Orbit
PrimaryA
CompanionBC
Period (P)≈80 [4] yr
Orbit [7]
PrimaryB
CompanionC
Period (P)36 yr
Semi-major axis (a)444 mas (9.217 AU) [b]
Eccentricity (e)0.136
Inclination (i)82.21°
Argument of periastron (ω)
(secondary)
109.8°
Position (relative to A) [4]
Epoch of observation December 2006
Angular distance 751 (A–B)
708 (A–C)
51 (B–C) mas
Position angle 342.5 (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 [9]
Database references
SIMBAD data
Exoplanet Archive data

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. [8]

Contents

Stellar system

Gliese 900 imaged by WISE, with the planetary-mass companion circled GJ900 AB unWISE.jpg
Gliese 900 imaged by WISE, with the planetary-mass companion 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, [4] 0.72 times its radius, [6] and 12% its luminosity. [2] A light curve from the Transiting Exoplanet Survey Satellite (TESS) shows that its rotational period is 12 days. [8] Gliese 900 A has a high level of chromospheric and coronal activity, although its apparent brightness presents little variation. [10] 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. [4]

The system is young, about 200 million years old, and is a likely member (99.7% probability) of the nearby moving group Carina-Near. [11] 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. [8] The emission of X-rays is typical of young stars, and classifies it as one. [10] The TESS light curve identifies stellar flares on this star. [8]

Orbit

Gliese 900 B and C form an inner pair (named Gliese 900 BC) with an orbital period of around 36 years. [7] Gliese 900 BC and Gliese 900 A orbit the system's center of mass with a period of 80 years. [4] [8] 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. [4] 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. [10] A further study by Malogolovets et al. (2007) identified this system as a hierarchical triple. [4]

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. [4] However, these faint stars haven't been confirmed as members of the GJ 900 system, and are likely not associated. [8]

Motion

Gliese 900 is located 68  light-years from Earth, based on parallax measurements by the Gaia spacecraft. [2] The BP-RP spectra suggest a distance of 67.7 ly. [2] The space velocity components of this system are U = −28.7, V = −15 and W = 0.2. [12] Gliese 900 is part of the thin disk population of the Milky Way. [12] [4] It was once classified as part of the IC 2602 supercluster. [10] 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. [8]

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. [8] This object, also called Gliese 900 b or Gliese 900 (ABC)b, [13] [14] 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 [8] and a temperature of 500  K. [15] 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 AU. [8]

As of 2024, Gliese 900 b has the largest observed separation of any known planet, and assuming a circular orbit, the longest orbital period. [16] [17] [c] The orbital period is estimated at 1.27 million years based on the projected separation. [18] Due to the similar spectral type, orbital separation and age, Gliese 900 b has been compared to COCONUTS-2b by the discovery team. [8]

Also in 2024, a study using data from Wide-field Infrared Survey Explorer found a red W2-W3 color for Gliese 900 b, 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. [15]

Gliese 900 planetary system [8]
Companion
(in order from star)
Mass Projected separation
(AU)
Orbital period (106 years) Eccentricity Inclination Radius
b10.5  MJ 12,0001.27 [18]   

See also

Notes

  1. 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.
  2. Using the angular separation and the parallax (both in milliarcseconds), the physical separation (in AU) can be obtained.
    444/48.17 = 9.217 AU.
  3. Out of objects with a planetary mass (<13 MJ). Exoplanet databases list a few brown dwarfs at larger separations.

    References

    1. Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters . 38 (5): 331. arXiv: 1108.4971 . Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. XHIP record for this object at VizieR.
    2. 1 2 3 4 5 6 7 8 9 10 11 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. Koen, C.; Kilkenny, D.; Van Wyk, F.; Marang, F. (2010). "UBV(RI)C JHK observations of Hipparcos-selected nearby stars". Monthly Notices of the Royal Astronomical Society. 403 (4): 1949. Bibcode:2010MNRAS.403.1949K. doi: 10.1111/j.1365-2966.2009.16182.x .
    4. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 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.
    5. 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.
    6. 1 2 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.
    7. 1 2 3 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.
    8. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 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.
    9. "GJ 900". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved June 17, 2024.
    10. 1 2 3 4 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.
    11. 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.
    12. 1 2 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.
    13. "GJ 900 Overview". NASA Exoplanet Archive . Retrieved June 17, 2024.
    14. "The Extrasolar Planet Encyclopaedia — GJ 900 (ABC)b". Extrasolar Planets Encyclopaedia . Paris Observatory.
    15. 1 2 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". The Astrophysical Journal. 979 (2): 145. arXiv: 2411.03549 . Bibcode:2025ApJ...979..145L. doi: 10.3847/1538-4357/ad8fa6 .
    16. Martin, Pierre-Yves (1995). "Catalogue of Exoplanets". exoplanet.eu. Retrieved 2024-06-20.
    17. "Planetary Systems Composite Data". NASA Exoplanet Archive . Retrieved 25 June 2024.
    18. 1 2 "GJ 900 b - NASA Science". science.nasa.gov. 31 May 2024. Retrieved 2024-06-20.