Banyan. Ii. Very Low Mass and Substellar Candidate Members to Nearby, Young Kinematic Groups With Previously Known Signs of Youth

Gagné, Jonathan; Lafrenière, David; Doyon, René; Malo, Lison; Artigau, Étienne

doi:10.1088/0004-637x/783/2/121

Cited by 294 publications

(646 citation statements)

References 146 publications

Supporting

Mentioning

614

Contrasting

Order By: Relevance

“…Its low rotation rate and weak magnetic activity suggest an age older than ∼0.1 Gyr. Its kinematics place it in the young disk population (Correia et al 2010), but this does not put a strong constraint on its age (i.e., 5 Gyr, Leggett 1992 (Nidever et al 2002) with the BANYANII tool (Malo et al 2013;Gagné et al 2014), we obtain a significant probability (P=85.1%) that this system is a member of the βPictoris moving group, which is comparable to its other bona fide members (Gagné et al 2014). Its UVW space velocity and XYZ galactic position place it at 5.05±1.80 km s −1 and 13.3±15.9 pc from the locus of known βPictoris moving group members.…”

Section: Rv Variable Targetsmentioning

confidence: 83%

“…Its UVW space velocity and XYZ galactic position place it at 5.05±1.80 km s −1 and 13.3±15.9 pc from the locus of known βPictoris moving group members. The probability of a random interloper at such spatial and kinematic distances from the locus of the group (counting both young and old stars) is only ≈1.3% (Gagné et al 2014). However, there are several indications in the literature that this system is old.…”

Section: Rv Variable Targetsmentioning

confidence: 99%

See 1 more Smart Citation

A High-Precision Near-Infrared Survey for Radial Velocity Variable Low-Mass Stars Using Cshell and a Methane Gas Cell

Gagné

Plavchan

Gao

et al. 2016

ApJ

Self Cite

233

View full text Add to dashboard Cite

We present the results of a precise near-infrared (NIR) radial velocity (RV) survey of 32 low-mass stars with spectral types K2-M4 using CSHELL at the NASA InfraRed Telescope Facility in the K band with an isotopologue methane gas cell to achieve wavelength calibration and a novel, iterative RV extraction method. We surveyed 14 members of young (≈25-150 Myr) moving groups, the young field star εEridani, and 18 nearby (<25 pc) low-mass stars and achieved typical single-measurement precisions of 8-15 m s −1 with a long-term stability of 15-50 m s −1 over longer baselines. We obtain the best NIR RV constraints to date on 27 targets in our sample, 19 of which were never followed by high-precision RV surveys. Our results indicate that very active stars can display long-term RV variations as low as ∼25-50 m s −1 at ≈2.3125 μm, thus constraining the effect of jitter at these wavelengths. We provide the first multiwavelength confirmation of GJ876bc and independently retrieve orbital parameters consistent with previous studies. We recovered RV variabilities for HD160934AB and GJ725AB that are consistent with their known binary orbits, and nine other targets are candidate RV variables with a statistical significance of 3σ-5σ. Our method, combined with the new iSHELL spectrograph, will yield long-term RV precisions of 5 m s −1 in the NIR, which will allow the detection of super-Earths near the habitable zone of mid-M dwarfs.

show abstract

Section: Rv Variable Targetsmentioning

confidence: 83%

Section: Rv Variable Targetsmentioning

confidence: 99%

A High-Precision Near-Infrared Survey for Radial Velocity Variable Low-Mass Stars Using Cshell and a Methane Gas Cell

Gagné

Plavchan

Gao

et al. 2016

ApJ

Self Cite

233

View full text Add to dashboard Cite

show abstract

“…These spectra display weak alkali lines, which are indicative of low surface gravity, and strong Li I absorption. Although Schlieder et al (2012) had previously identified LSPMJ1314+1320AB as a likely new member of the AB Doradus moving group (∼150 Myr), subsequent analysis and updated proper motion data has led to the conclusion that it cannot be confidently associated with any known group (Gagné et al 2014;Schlieder et al 2014). McLean et al (2011) has also identified LSPMJ1314+1320AB as a source of bright (∼1 mJy), persistent radio emission with a flat spectrum across a wide range of frequencies (1.43-22.5 GHz), suggesting high levels of magnetic activity and a stable, large-scale magnetosphere (Williams et al 2014(Williams et al , 2015.…”

Section: Introductionmentioning

confidence: 99%

High-Precision Radio and Infrared Astrometry of LSPM J1314+1320ab. Ii. Testing Pre-Main-Sequence Models at the Lithium Depletion Boundary With Dynamical Masses

Dupuy

Forbrich

Rizzuto

et al. 2016

ApJ

View full text Add to dashboard Cite

We present novel tests of pre-main-sequence models based on individual dynamical masses for the M7 binary LSPMJ1314+1320AB. Joint analysis of Keck adaptive optics astrometric monitoring along with Very Long Baseline Array radio data from a companion paper yield component masses of 92.8±0.6 M Jup (0.0885±0.0006 M ☉ ) and 91.7±1.0 M Jup (0.0875±0.0010 M ☉ ) and a parallactic distance of 17.249±0.013 pc. We find component luminosities consistent with the system being coeval at 80.8±2.5 Myr, according to BHAC15 evolutionary models. The presence of lithium is consistent with model predictions, marking the first test of the theoretical lithium depletion boundary using ultracool dwarfs of known mass. However, we find that the evolutionary model-derived average effective temperature (2950±5 K) is 180 K hotter than that given by a spectral type-T eff relation based on BT-Settl models (2770±100 K). We suggest that the dominant source of this discrepancy is model radii being too small by ≈13%. In a test mimicking the typical application of models by observers, we derive masses on the H-R diagram using luminosity and BT-Settl temperature. The estimated masses are lower by -(2.0σ) than we measure dynamically and would imply that this is a system of ≈50 M Jup brown dwarfs, highlighting the large systematic errors possible in H-R diagram properties. This is the first time masses have been measured for ultracool ( M6) dwarfs displaying spectral signatures of low gravity. Based on features in the infrared, LSPMJ1314+1320AB appears to have higher gravity than typical Pleiades and ABDor members, opposite the expectation given its younger age. The components of LSPMJ1314+1320AB are now the nearest, lowest mass pre-main-sequence stars with direct mass measurements.

show abstract

“…Nakajima & Morino (2012) conclude that β Cir may be a member of the TW Hydrae stellar kinematic group (∼ 8 − 12 Myr) and three other moving groups at a lower probability. The BANYAN II web tool (Gagné et al 2014, Malo et al 2013) operating under the assumption that β Cir is < 1 Gyr old gives a zero percent probability of TW Hydrae membership and 66, 21 and 13 percent probabilities of membership to the β Pictoris (∼ 12 − 22 Myr), AB Doradus (∼ 70−120 Myr) and field groups respectively. Indicators of youth in addition to spatial and kinematic agreement with a moving group are required to consider an object a genuine member.…”

Section: The Age Of the β Cir Systemmentioning

confidence: 99%

Discovery of a brown dwarf companion to the A3V star β Circini

Smith

Lucas

Peña

et al. 2015

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

We report the discovery of an L dwarf companion to the A3V star β Circini. VVV J151721.49-585131.5, or β Cir B, was identified in a proper motion and parallax catalogue of the Vista Variables in the Vía Láctea survey as having near infrared luminosity and colour indicative of an early L dwarf, and a proper motion and parallax consistent with that of β Cir. The projected separation of ∼3.6 ′ corresponds to 6656 au, which is unusually wide. The most recent published estimate of the age of the primary combined with our own estimate based on newer isochrones yields an age of 370 − 500 Myr. The system therefore serves as a useful benchmark at an age greater than that of the Pleiades brown dwarfs and most other young L dwarf benchmarks. We have obtained a medium resolution echelle spectrum of the companion which indicates a spectral type of L1.0±0.5 and lacks the typical signatures of low surface gravity seen in younger brown dwarfs. This suggests that signs of low surface gravity disappear from the spectra of early L dwarfs by an age of ∼ 370 − 500 Myr, as expected from theoretical isochrones. The mass of β Cir B is estimated from the BHAC15 isochrones as 0.056 ± 0.007 M ⊙ .

show abstract

Banyan. Ii. Very Low Mass and Substellar Candidate Members to Nearby, Young Kinematic Groups With Previously Known Signs of Youth

Cited by 294 publications

References 146 publications

A High-Precision Near-Infrared Survey for Radial Velocity Variable Low-Mass Stars Using Cshell and a Methane Gas Cell

A High-Precision Near-Infrared Survey for Radial Velocity Variable Low-Mass Stars Using Cshell and a Methane Gas Cell

High-Precision Radio and Infrared Astrometry of LSPM J1314+1320ab. Ii. Testing Pre-Main-Sequence Models at the Lithium Depletion Boundary With Dynamical Masses

Discovery of a brown dwarf companion to the A3V star β Circini

Contact Info

Product

Resources

About