2M1207
2M1207,
2M1207A
or
2MASS
J12073346–3932539 is a brown dwarf
located in the constellation Centaurus; a
companion object, 2M1207b, may be the
first extrasolar planetary-mass companion to
be directly imaged, and is the first
discovered orbiting a brown dwarf.[5][6]
2M1207 was discovered during the course
of the 2MASS infrared sky survey: hence
the "2M" in its name, followed by its
celestial coordinates. With a fairly early (for
a brown dwarf) spectral type of M8,[1] it is
very young, and probably a member of the
TW Hydrae association. Its estimated mass
is around 25 Jupiter masses.[4] The
companion, 2M1207b, is estimated to have
a mass of 5–6 Jupiter masses.[7] Still
glowing red hot, it will shrink to a size
slightly smaller than Jupiter as it cools over
the next few billion years.
An initial photometric estimate for the
distance to 2M1207 was 70 parsecs.[4] In
December 2005, American astronomer Eric
Mamajek reported a more accurate distance
(53 ± 6 parsecs) to 2M1207 using the
moving cluster method.[8] The new distance
gives a fainter luminosity for 2M1207.
Recent trigonometric parallax results have
confirmed this moving cluster distance,
leading to a distance estimate of 53 ± 1
parsec or 172 ± 3 light years.[4]
Planetary system
Like classical T Tauri stars, many brown
dwarfs are surrounded by disks of gas and
dust which accrete onto the brown
dwarf.[9][10] 2M1207 was first suspected to
have such a disk because of its broad Hα
line. This was later confirmed by ultraviolet
spectroscopy.[10] The existence of a dust
2M1207
European Southern Observatory infrared image of
2M1207 (bluish) and companion planet 2M1207b
(reddish), taken in 2004.
Observation data
Epoch J2000.0
Equinox J2000.0 (ICRS)
Constellation
Centaurus
Right ascension
12h 07m 33.47s[1]
Declination
−39° 32′ 54.0″[1]
Apparent magnitude (V) 20.15[2]
Characteristics
Spectral type
M8IVe C[1]
V−R color index
+2.1[2]
R−I color index
+2.1[2]
Astrometry
Proper motion (μ)
RA: −64.040 ± 0.087[3] mas/yr
Dec.: −23.678 ± 0.072[3] mas/yr
Parallax (π)
15.4624 ± 0.1163 mas[3]
Distance
211 ± 2 ly
(64.7 ± 0.5 pc)
Details
Mass
~0.025[4] M☉
Radius
~0.25[5] R☉
Luminosity
~0.002[5] L☉
Temperature
2550 ± 150[5] K
disk has also been confirmed by infrared Age
5·106 to 10·106[5] years
[11]
[12]
observations
and with ALMA.
In
Other designations
general, accretion from disks are known to
produce fast-moving jets, perpendicular to 2MASSW J1207334−393254, 2MASS
[1]
the disk, of ejected material.[13] This has J12073346-3932539, TWA 27
Database references
also been observed for 2M1207; an April
2007 paper in the Astrophysical Journal SIMBAD
data (https://simbad.cds.unistr
reports that this brown dwarf is spouting jets
a.fr/simbad/sim-id?Ident=NAM
[14]
of material from its poles.
The jets,
E+2M1207A)
9
which extend around 10 kilometers into
space, were discovered using the Very Large Telescope (VLT) at the European Southern Observatory.
Material in the jets streams into space at a few kilometers per second.[15]
2M1207b shows weak accretion from a disk, inferred from emission lines of hydrogen and helium in
medium-resolution NIRSpec data. Surprisingly 2M1207b does not show absorption due to methane, which
was predicted to be present for this object. It was suggested that very young objects have a L/T-transition
starts at a later spectral type.[16]
The 2M1207A planetary system[7][12][17]
Companion
(in order from star)
Mass
Semimajor axis
Orbital period
(AU)
(years)
circumstellar disk
b
Eccentricity
9.4 ± 1.5 AU
5–6 MJ
≥49.8 ± 1.1[18]
633-20046
0.02-0.98
Inclination
Radius
35 −15°
+20
—
13-150°
—
See also
Lists of exoplanets
Direct imaging of extrasolar planets
References
1. "TWA 27" (http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=TWA+27). SIMBAD. Centre de
données astronomiques de Strasbourg. Retrieved June 15, 2008.
2. An accurate distance to 2M1207Ab, C. Ducourant, R. Teixeira, G. Chauvin, G. Daigne, J.-F.
Le Campion, Inseok Song, and B. Zuckerman, Astronomy and Astrophysics 477, #1
(January 2008), pp. L1–L4. Bibcode:2008A&A...477L...1D (https://ui.adsabs.harvard.edu/ab
s/2008A&A...477L...1D/abstract) doi:10.1051/0004-6361:20078886 (https://doi.org/10.1051%
2F0004-6361%3A20078886).
3. Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of
the contents and survey properties" (https://doi.org/10.1051%2F0004-6361%2F202039657).
Astronomy & Astrophysics. 649: A1. arXiv:2012.01533 (https://arxiv.org/abs/2012.01533).
Bibcode:2021A&A...649A...1G (https://ui.adsabs.harvard.edu/abs/2021A&A...649A...1G).
doi:10.1051/0004-6361/202039657 (https://doi.org/10.1051%2F0004-6361%2F202039657).
S2CID 227254300 (https://api.semanticscholar.org/CorpusID:227254300).
(Erratum: doi:10.1051/0004-6361/202039657e (https://doi.org/10.1051%2F0004-6361%2F202039
657e)). Gaia EDR3 record for this source (http://vizier.u-strasbg.fr/viz-bin/VizieR-S?Gaia%20
EDR3%203459372646830687104) at VizieR.
4. "The Distance to the 2M1207 System" (http://www.cfa.harvard.edu/~emamajek/memo_2m12
07.html) Archived (https://web.archive.org/web/20080124115127/http://www.cfa.harvard.edu/
~emamajek/memo_2m1207.html) 2008-01-24 at the Wayback Machine, Eric Mamajek,
November 8, 2007. Accessed on line June 15, 2008.
5. The Planetary Mass Companion 2MASS 1207-3932B: Temperature, Mass, and Evidence for
an Edge-on Disk, Subhanjoy Mohanty, Ray Jayawardhana, Nuria Huelamo, and Eric
Mamajek, Astrophysical Journal 657, #2 (March 2007), pp. 1064–1091.
Bibcode:2007ApJ...657.1064M (https://ui.adsabs.harvard.edu/abs/2007ApJ...657.1064M/abs
tract) doi:10.1086/510877 (https://doi.org/10.1086%2F510877).
6. Chauvin, G.; Lagrange, A.-M.; Dumas, C.; Zuckerman, B.; Mouillet, D.; Song, I.; Beuzit, J.-L.;
Lowrance, P. (2004). "A Giant Planet Candidate near a Young Brown Dwarf". Astron.
Astrophys. 425 (2): L29–L32. arXiv:astro-ph/0409323 (https://arxiv.org/abs/astro-ph/040932
3). Bibcode:2004A&A...425L..29C (https://ui.adsabs.harvard.edu/abs/2004A&A...425L..29C).
doi:10.1051/0004-6361:200400056 (https://doi.org/10.1051%2F0004-6361%3A200400056).
S2CID 15948759 (https://api.semanticscholar.org/CorpusID:15948759).
7. Luhman, K. L.; Tremblin, P.; Birkmann, S. M.; Manjavacas, E.; Valenti, J.; Alves de Oliveira,
C.; Beck, T. L.; Giardino, G.; Lützgendorf, N.; Rauscher, B. J.; Sirianni, M. (2023-06-01).
"JWST/NIRSpec Observations of the Planetary Mass Companion TWA 27B" (https://ui.adsa
bs.harvard.edu/abs/2023ApJ...949L..36L). The Astrophysical Journal. 949: L36.
arXiv:2305.18603 (https://arxiv.org/abs/2305.18603). doi:10.3847/2041-8213/acd635 (https://
doi.org/10.3847%2F2041-8213%2Facd635). ISSN 0004-637X (https://www.worldcat.org/iss
n/0004-637X).
8. Mamajek (2005). "A Moving Cluster Distance to the Exoplanet 2M1207b in the TW Hydrae
Association". The Astrophysical Journal. 634 (2): 1385–1394. arXiv:astro-ph/0507416 (http
s://arxiv.org/abs/astro-ph/0507416). Bibcode:2005ApJ...634.1385M (https://ui.adsabs.harvar
d.edu/abs/2005ApJ...634.1385M). doi:10.1086/468181 (https://doi.org/10.1086%2F468181).
S2CID 17162407 (https://api.semanticscholar.org/CorpusID:17162407).
9. More Sun-like stars may have planetary systems than currently thought (http://origins.jpl.nas
a.gov/library/extrasolar/121302-a.html) Archived (https://web.archive.org/web/200809171734
20/http://origins.jpl.nasa.gov/library/extrasolar/121302-a.html) 2008-09-17 at the Wayback
Machine, library, Origins program, NASA. Accessed on line June 16, 2008.
10. First Ultraviolet Spectrum of a Brown Dwarf: Evidence for H2 Fluorescence and Accretion,
John E. Gizis, Harry L. Shipman, and James A. Harvin, Astrophysical Journal 630, #1
(September 2005), pp. L89–L91. Bibcode:2005ApJ...630L..89G (https://ui.adsabs.harvard.ed
u/abs/2005ApJ...630L..89G/abstract) doi:10.1086/462414 (https://doi.org/10.1086%2F46241
4).
11. Spitzer Observations of Two TW Hydrae Association Brown Dwarfs, Basmah Riaz, John E.
Gizis, and Abraham Hmiel, Astrophysical Journal 639, #2 (March 2006), pp. L79–L82.
Bibcode:2006ApJ...639L..79R (https://ui.adsabs.harvard.edu/abs/2006ApJ...639L..79R/abstr
act) doi:10.1086/502647 (https://doi.org/10.1086%2F502647).
12. Ricci, L.; Cazzoletti, P.; Czekala, I.; Andrews, S. M.; Wilner, D.; Szűcs, L.; Lodato, G.; Testi, L.;
Pascucci, I.; Mohanty, S.; Apai, D.; Carpenter, J. M.; Bowler, B. P. (2017-07-01). "ALMA
Observations of the Young Substellar Binary System 2M1207" (https://ui.adsabs.harvard.ed
u/abs/2017AJ....154...24R). The Astronomical Journal. 154: 24. doi:10.3847/15383881/aa78a0 (https://doi.org/10.3847%2F1538-3881%2Faa78a0). hdl:10150/624920 (http
s://hdl.handle.net/10150%2F624920). ISSN 0004-6256 (https://www.worldcat.org/issn/00046256).
13. Accretion-ejection models of astrophysical jets, R. E. Pudritz, in Accretion Disks, Jets and
High-energy Phenomena in Astrophysics, Vassily Beskin, Gilles Henri, Francois Menard,
Guy Pelletier, and Jean Dalibard, eds., NATO Advanced Study Institute, Les Houches,
session LXXVIII, EDP Sciences/Springer, 2003. ISBN 3-540-20171-8.
14. Whelan; Ray, T. P.; Randich, S.; Bacciotti, F.; Jayawardhana, R.; Testi, L.; Natta, A.; Mohanty,
S.; et al. (April 10, 2007). "Discovery of a Bipolar Outflow from 2MASSW J1207334-393254,
a 24 MJup Brown Dwarf". The Astrophysical Journal. 659 (1): L45–L48. arXiv:astroph/0703112 (https://arxiv.org/abs/astro-ph/0703112). Bibcode:2007ApJ...659L..45W (https://u
i.adsabs.harvard.edu/abs/2007ApJ...659L..45W). doi:10.1086/516734 (https://doi.org/10.108
6%2F516734). S2CID 14575014 (https://api.semanticscholar.org/CorpusID:14575014).
15. Small Stars Create Big Fuss (http://www.space.com/scienceastronomy/070528_mm_bdwarf
_jets.html), Ker Than, May 28, 2007, space.com. Accessed on line June 15, 2008.
16. Elena, Manjavacas; Tremblin, Pascal; Birkmann, Stephan; Valenti, Jeff; Alves de Oliveira,
Catarina; Beck, Tracy L.; Giardino, G.; Luetzgendorf, N.; Rauscher, B. J.; Sirianni, M.
(February 2024). "Medium Resolution 0.97-5.3 micron spectra of Very Young Benchmark
Brown Dwarfs with NIRSpec onboard the James Webb Space Telescope" (https://ui.adsabs.
harvard.edu/abs/2024arXiv240204230M/abstract). AJ. arXiv:2402.04230 (https://arxiv.org/ab
s/2402.04230).
17. Blunt, Sarah; Nielsen, Eric L.; De Rosa, Robert J.; Konopacky, Quinn M.; Ryan, Dominic;
Wang, Jason J.; Pueyo, Laurent; Rameau, Julien; Marois, Christian; Marchis, Franck;
Macintosh, Bruce; Graham, James R.; Duchêne, Gaspard; Schneider, Adam C. (2017-0501). "Orbits for the Impatient: A Bayesian Rejection-sampling Method for Quickly Fitting the
Orbits of Long-period Exoplanets" (https://ui.adsabs.harvard.edu/abs/2017AJ....153..229B).
The Astronomical Journal. 153: 229. arXiv:1703.10653 (https://arxiv.org/abs/1703.10653).
doi:10.3847/1538-3881/aa6930 (https://doi.org/10.3847%2F1538-3881%2Faa6930).
ISSN 0004-6256 (https://www.worldcat.org/issn/0004-6256).
18. From Gaia distance of 64.7 ± 0.5 parsec and observed angular separation of 769 ± 10
milliarseconds (angular separation from Mohanty 2007, above.) Real semimajor axis might
be higher due to viewing angle and eccentricity of the orbit.
External links
Space.com - Astronomers Confident: Planet Beyond Solar System Has Been Photographed
(http://space.com/scienceastronomy/aas_exoplanet_050110.html)
Space.com article on the discovery (http://www.space.com/scienceastronomy/planet_photo_
040910.html)
Jean Schneider (2011). "Notes for star 2M1207" (https://web.archive.org/web/201110060040
13/http://exoplanet.eu/star.php?st=2M1207). Extrasolar Planets Encyclopaedia. Archived
from the original (http://exoplanet.eu/star.php?st=2M1207) on 6 October 2011. Retrieved
3 October 2011.
"A Giant Planet Candidate Near a Young Brown Dwarf" (PDF) (https://web.archive.org/web/2
0041013153848/http://www.sc.eso.org/~gchauvin/Gg222.pdf) from the European Southern
Observatory.
"A Moving Cluster Distance to the Exoplanet 2M1207b in the TW Hydrae Association" (http
s://arxiv.org/abs/astro-ph/0507416)
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