Astronomy:2MASS J18352154−3123385

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Short description: Binary red dwarf system in the constellation Sagittarius
2MASS J18352154−3123385
Observation data
{{#ifeq:J2000.0|J2000.0 (ICRS)|Epoch J2000.0      Equinox J2000.0 (ICRS)| Epoch J2000.0      [[Astronomy:Equinox (celestial coordinates)|Equinox J2000.0}}
Constellation Sagittarius[1]
2MASS J18352154-3123385
Right ascension  18h 35m 21.543s[citation needed]
Declination −31° 23′ 38.53″[citation needed]
Apparent magnitude (V) 12.5
2MASS J18352205-3123421
Right ascension  18h 35m 22.050s[citation needed]
Declination −31° 23′ 42.19″[citation needed]
Apparent magnitude (V) 13.0[citation needed]
Characteristics
2MASS J18352154−3123385
Spectral type M6.5V[citation needed]
Apparent magnitude (J) 8.652
Apparent magnitude (H) 8.097
Apparent magnitude (K) 7.803
Characteristics
2MASS J18352205−3123421
Spectral type M8V[citation needed]
Apparent magnitude (J) 9.438[citation needed]
Apparent magnitude (H) 8.815[citation needed]
Apparent magnitude (K) 8.533[citation needed]
Astrometry
2MASS J18352154−3123385
Proper motion (μ) RA: +21±4[2] mas/yr
Dec.: −382±4[2] mas/yr
Parallax (π)58.16 ± 0.04[citation needed] mas
Distance56.08 ± 0.04 ly
(17.19 ± 0.01 pc)
2MASS J18352205−3123421
Proper motion (μ) RA: +28.53±0.04 mas/yr
Dec.: −380.00±0.04 mas/yr
Parallax (π)58.0782 ± 0.0480[3] mas
Distance56.16 ± 0.05 ly
(17.22 ± 0.01 pc)
Orbit
Primary2MASS J18352154−3123385
Companion2MASS J18352205−3123421
Period (P)~1400–1800?[citation needed] yr
Semi-major axis (a)5070 AU[citation needed]
Inclination (i)~55[citation needed]°
Longitude of the node (Ω)~5[citation needed]°
Periastron epoch (T)~1968[lower-alpha 1]
Details[4]
2MASS J18352154−3123385
Mass0.29 M☉
Radius0.3 R☉
Luminosity0.0012 L☉
Temperature3376 K
Metallicity [Fe/H]-0.07 dex
2MASS J18352205−3123421
Other designations
1RXS J183520.9−312327, PM J18353−3123W, LP 923-18
2MASS J18352154−3123385: LP923-18, PM J18353−3123W[5]
2MASS J18352205−3123421: LP923-19, PM J18353−3123E[6]
Database references
SIMBAD2MASS J18352154–3123385
2MASS J18352205-3123421

2MASS J18352154−3123385, often shortened to be 2MASS J1835, is a binary red dwarf system about 56 light-years from the Earth. It was first reported due to its high proper motion in 2010 by J. D. Kirkpatrick et al.[7][8] It was then independently discovered from its X-ray radiation on June 10, 2015. Further investigation has shown the star to be a binary star with components of spectral type M6.5 and M8. They orbit each other in 1,400-1,800 years, and reached their closest point in mid-1968 assuming a constant proper motion. During their closest approach, they were separated by less than 0.1 arcsecond, compared to their current separation of 2 arcseconds.

Despite the fact that A and B are magnitude 12.5 and 13, respectively, their vicinity to the Earth was not noticed until 2015 due to the fact that it is in front of a relatively dense star field less than 15 degrees away from the Galactic Center. 2MASS J1835A may be a flare star, due to many similar low-mass stars known to flare. It has not been observed to flare directly by 2015, however.

A 19th-magnitude star at  18h 35m 22.76s −31° 23′ 27.7″ has been seen in the vicinity, with a similar proper motion to 2MASS J1835, but is probably not related as its proper motion is not as high as 2MASS J1835. Due to its dimness, insufficient data exists to determine its spectral type.

See also

Notes

  1. ↑ given date is not the date of periastron, but rather the date of the closest separation between 2MASS J1835A and B.

References

  1. ↑ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific 99 (617): 695. doi:10.1086/132034. Bibcode: 1987PASP...99..695R  Constellation record for this object at VizieR.
  2. ↑ URAT South Parallax Results Table 5. New Nearby Star Discoveries URAT South Epoch Data
  3. ↑ Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode: 2021A&A...649A...1G.  Gaia EDR3 record for this source at VizieR.
  4. ↑ Trumpeting M dwarfs with CONCH-SHELL: a catalogue of nearby cool host-stars for habitable exoplanets and life supplementary data
  5. ↑ "2MASS J18352154-3123385". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=2MASS+J18352154-3123385. 
  6. ↑ "2MASS J18352205-3123421". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=2MASS+J18352205-3123421. 
  7. ↑ Kirkpatrick, J. Davy (2010). "Discoveries from a Near-Infrared Proper Motion Survey using Multi-Epoch Two Micron All-Sky Survey Data". The Astrophysical Journal Supplement Series (Institution of Physics) 190 (1): 100–146. doi:10.1088/0067-0049/190/1/100. Bibcode: 2010ApJS..190..100K. 
  8. ↑ Kirkpatrick, J. D.. "Discoveries from a Near-infrared Proper Motion Survey using Multi-epoch 2MASS Data (full text table)". Institute of Physics. http://iopscience.iop.org/0067-0049/190/1/100/fulltext/apjs342915t1_mrt.txt. Retrieved 21 December 2015.