New Isolated Planetary-Mass Objects and the Stellar and Substellar Mass Function of the Σ Orionis Cluster

Ramírez, K. Peña; Béjar, V. J. S.; Osorio, M. R. Zapatero; Petr-Gotzens, M. G.; Martín, E. L.

doi:10.1088/0004-637x/754/1/30

Cited by 131 publications

(126 citation statements)

References 103 publications

Supporting

Mentioning

105

Contrasting

Order By: Relevance

“…CVSO Hewett et al (2006). CVSO 30 c clearly stands out in the lower left corner, approximately consistent with colours of giants, early-M and early-T dwarfs, and free-floating planetary mass objects (Zapatero Osorio et al 2000;Peña Ramírez et al 2012), e.g. consistent with absolute magnitude and J-Ks colour of S Ori 64.…”

Section: Astrometric and Photometric Analysissupporting

confidence: 71%

“…We find that background stars of spectral types OBAFGK are too blue in J-H, late-M dwarfs are too blue in J-H and too red in H-K, while foreground L-and late T-dwarfs are either too red in H-K or too blue in J-H. In addition, background galaxies, quasars, and H/He white dwarfs are also inconsistent with the values of CVSO 30 c. Only late-type giants, early-M and early-T dwarfs, and planetary mass free-floating objects such as are found in the σ Orionis star cluster have comparable colours (Zapatero Osorio et al 2000;Peña Ramírez et al 2012). …”

Section: Astrometric and Photometric Analysismentioning

confidence: 99%

See 1 more Smart Citation

Direct Imaging discovery of a second planet candidate around the possibly transiting planet host CVSO 30

Schmidt

Neuhäuser

Vogt

et al. 2016

A&A

View full text Add to dashboard Cite

Context. Direct imaging has developed into a very successful technique for the detection of exoplanets in wide orbits, especially around young stars. Directly imaged planets can be both followed astrometrically on their orbits and observed spectroscopically and thus provide an essential tool for our understanding of the early solar system. Aims. We surveyed the 25 Ori association for direct-imaging companions. This association has an age of only few million years. Among other targets, we observed CVSO 30, which has recently been identified as the first T Tauri star found to host a transiting planet candidate. Methods. We report on photometric and spectroscopic high-contrast observations with the Very Large Telescope, the Keck telescopes, and the Calar Alto observatory. They reveal a directly imaged planet candidate close to the young M3 star CVSO 30. Results. The JHK-band photometry of the newly identified candidate is at better than 1 σ consistent with late-type giants, early-T and early-M dwarfs, and free-floating planets. Other hypotheses such as galaxies can be excluded at more than 3.5 σ. A lucky imaging z ′ photometric detection limit z ′ = 20.5 mag excludes early-M dwarfs and results in less than 10 M Jup for CVSO 30 c if bound. We present spectroscopic observations of the wide companion that imply that the only remaining explanation for the object is that it is the first very young (< 10 Myr) L -T-type planet bound to a star, meaning that it appears bluer than expected as a result of a decreasing cloud opacity at low effective temperatures. Only a planetary spectral model is consistent with the spectroscopy, and we deduce a best-fit mass of 4 -5 Jupiter masses (total range 0.6 -10.2 Jupiter masses). Conclusions. This means that CVSO 30 is the first system in which both a close-in and a wide planet candidate are found to have a common host star. The orbits of the two possible planets could not be more different: they have orbital periods of 10.76 hours and about 27000 years. The two orbits may have formed during a mutual catastrophic event of planet-planet scattering.

show abstract

Section: Astrometric and Photometric Analysissupporting

confidence: 71%

Section: Astrometric and Photometric Analysismentioning

confidence: 99%

Direct Imaging discovery of a second planet candidate around the possibly transiting planet host CVSO 30

Schmidt

Neuhäuser

Vogt

et al. 2016

A&A

View full text Add to dashboard Cite

show abstract

“…In others, like the σ Orionis open cluster (Bihain et al 2009;Caballero et al 2007;Lodieu et al 2009;Peña Ramírez et al 2012) and in the Pleiades (Bihain et al 2006;Zapatero Osorio et al 2014) a decline is not obvious near the HBML. All mass distributions appear to show a continuous transition from BDs to stars, albeit exhibiting different gradients.…”

Section: Continuity Of the Imf At The Vlms -Bd Transitionmentioning

confidence: 96%

Using binary statistics in Taurus-Auriga to distinguish between brown dwarf formation processes

Marks¹,

Martín

Béjar

et al. 2017

A&A

Self Cite

View full text Add to dashboard Cite

Context. Whether brown dwarfs (BDs) form just as stars directly from the gravitational collapse of a molecular cloud core ("star-like") or whether BDs and some very low-mass stars (VLMSs) constitute a separate population which form alongside stars comparable to the population of planets, e.g. through circumstellar disk ("peripheral") fragmentation, is one of the key questions of the star-formation problem. Aims. For young stars in Taurus-Auriga the binary fraction has been shown to be large with little dependence on primary mass above ≈ 0.2M⊙, while for BDs it is < 10%. Here we investigate a case in which BDs in Taurus formed dominantly, but not exclusively, through peripheral fragmentation, which naturally results in low binary fractions. The decline of the binary frequency in the transition region between star-like formation and peripheral formation is modelled. Methods. A dynamical population synthesis model is employed in which stellar binary formation is universal with a large binary fraction close to unity. Peripheral objects form separately in circumstellar disks with a distinctive initial mass function (IMF), own orbital parameter distributions for binaries and a low binary fraction according to observations and expectations from smoothed particle hydrodynamics (SPH) and grid-based computations. A small amount of dynamical processing of the stellar component is accounted for as appropriate for the low-density Taurus-Auriga embedded clusters. Results. The binary fraction declines strongly in the transition region between star-like and peripheral formation, exhibiting characteristic features. The location of these features and the steepness of this trend depend on the masslimits for star-like and peripheral formation. Such a trend might be unique to low density regions like Taurus which host dynamically largely unprocessed binary populations in which the binary fraction is large for stars down to M-dwarfs and low for BDs. Conclusions. The existence of a strong decline in the binary fraction -primary mass diagram will become verifiable in future surveys on BD and VLMS binarity in the Taurus-Auriga star forming region. It is a test of the (non-)continuity of star formation along the mass-scale, the separateness of the stellar and BD populations and the dominant formation channel for BDs and BD binaries in regions of low stellar density hosting dynamically unprocessed populations.

show abstract

“…This means stellar formation processes, such as cloud fragmentation (see for instance Bate 2009) or disk fragmentation (see for instance Stamatellos et al 2011), can form planetary mass objects. Peña Ramírez et al (2012) has recently identified a population of IPMOs in the σ-Orionis cluster, and hinted that they could be about as numerous as deuterium-burning brown dwarfs. This would indicate that there is a significant population of overlooked IPMOs in the solar vicinity, both in the field and in young moving groups and clusters.…”

Section: Introductionmentioning

confidence: 99%

CFBDSIR2149-0403: a 4–7 Jupiter-mass free-floating planet in the young moving group AB Doradus?

Delorme

Gagné

Malo

et al. 2012

A&A

View full text Add to dashboard Cite

Using the CFBDSIR wide field survey for brown dwarfs, we identified CFBDSIRJ214947.2-040308.9, a late T dwarf with an atypically red J − K S colour. We obtained an X-Shooter spectra, with signal detectable from 0.8 μm to 2.3 μm, which confirmed a T7 spectral type with an enhanced K s -band flux indicative of a potentially low-gravity, young object. The comparison of our near infrared spectrum with atmosphere models for solar metallicity shows that CFBDSIRJ214947.2-040308.9 is probably a 650−750 K, log g = 3.75−4.0 substellar object. Using evolution models, this translates into a planetary mass object with an age in the 20−200 Myr range. An independent Bayesian analysis from proper motion measurements results in a 87% probability that this free-floating planet is a member of the 50−120 Myr-old AB Doradus moving group, which strengthens the spectroscopic diagnosis of youth. By combining our atmospheric characterisation with the age and metallicity constraints arising from the probable membership to the AB Doradus moving group, we find that CFBDSIRJ214947.2-040308.9 is probably a 4−7 Jupiter mass, free-floating planet with an effective temperature of ∼700 K and a log g of ∼4.0, typical of the late T-type exoplanets that are targeted by direct imaging. We stress that this object could be used as a benchmark for understanding the physics of the similar T-type exoplanets that will be discovered by the upcoming high-contrast imagers.

show abstract

New Isolated Planetary-Mass Objects and the Stellar and Substellar Mass Function of the Σ Orionis Cluster

Cited by 131 publications

References 103 publications

Direct Imaging discovery of a second planet candidate around the possibly transiting planet host CVSO 30

Direct Imaging discovery of a second planet candidate around the possibly transiting planet host CVSO 30

Using binary statistics in Taurus-Auriga to distinguish between brown dwarf formation processes

CFBDSIR2149-0403: a 4–7 Jupiter-mass free-floating planet in the young moving group AB Doradus?

Contact Info

Product

Resources

About