From the Sun to Jupiter: Evolution of Low Mass Stars and Brown Dwarfs down to Planetary Masses

2006 ◽  
pp. 93-100
Author(s):  
Isabelle Baraffe ◽  
Gilles Chabrier ◽  
France Allard ◽  
Peter Hauschildt
Keyword(s):  
Brown Dwarfs ◽  
The Sun ◽  
Low Mass Stars ◽  
Low Mass

A proto-brown dwarf candidate in rho Ophiuchus

2021 ◽  
Vol 32 ◽  
Author(s):  
Phan Bao Ngoc
Keyword(s):  
Formation Process ◽  
Brown Dwarfs ◽  
Small Scale ◽  
The Sun ◽  
Formation Processes ◽  
Brown Dwarf ◽  
Low Mass Stars ◽  
Star Forming ◽  
Low Mass ◽  
Rho Ophiuchus

Brown dwarfs with masses below 0.075 solar masses are thought to form like low-mass stars (e.g., the Sun).However, it is still unclear how the physical formation processes occurin brown dwarfs at the ealiest stages (i.e., proto-brown dwarfs) of their formation.Up to date, only a few proto-brown dwarfs have been detected.The detection of proto-brown dwarfs offers us excellent benchmarks to studythe formation process of brown dwarfs, and thus understand their formation mechanism.In this paper, we present our identification of a proto-brown dwarf candidate in the star-forming regionrho Ophiuchus.The candidate shows a small-scale bipolar molecular outlfow that is similar to the outflows observed inother young brown dwarfs. The detection of this candidateprovides us with additional important implications for the formation mechanism of brown dwarfs.

scholarly journals Exploring Flaring Behaviour on Low Mass Stars, Solar-type Stars and the Sun

2019 ◽  
Vol 15 (S354) ◽  
pp. 384-391
Author(s):  
L. Doyle ◽  
G. Ramsay ◽  
J. G. Doyle ◽  
P. F. Wyper ◽  
E. Scullion ◽  
...  
Keyword(s):  
High Energy ◽  
The Sun ◽  
Low Mass Stars ◽  
Highly Active ◽  
Rotation Phase ◽  
Solar Type ◽  
Low Mass ◽  
Insight Into ◽  
Reconnection Model ◽  
High Cadence

AbstractWe report on our project to study the activity in both the Sun and low mass stars. Utilising high cadence, Hα observations of a filament eruption made using the CRISP spectropolarimeter mounted on the Swedish Solar Telescope has allowed us to determine 3D velocity maps of the event. To gain insight into the physical mechanism which drives the event we have qualitatively compared our observation to a 3D MHD reconnection model. Solar-type and low mass stars can be highly active producing flares with energies exceeding erg. Using K2 and TESS data we find no correlation between the number of flares and the rotation phase which is surprising. Our solar flare model can be used to aid our understanding of the origin of flares in other stars. By scaling up our solar model to replicate observed stellar flare energies, we investigate the conditions needed for such high energy flares.

scholarly journals Primeval very low-mass stars and brown dwarfs – II. The most metal-poor substellar object

2017 ◽  
Vol 468 (1) ◽  
pp. 261-271 ◽  
Author(s):  
Z. H. Zhang 张曾华 ◽  
D. Homeier ◽  
D. J. Pinfield ◽  
N. Lodieu ◽  
H. R. A. Jones ◽  
...  
Keyword(s):  
Brown Dwarfs ◽  
Low Mass Stars ◽  
Low Mass

scholarly journals A mid-infrared study of very low mass stars and brown dwarfs in Upper Scorpius

2006 ◽  
Vol 463 (2) ◽  
pp. 641-646 ◽  
Author(s):  
H. Bouy ◽  
N. Huélamo ◽  
E. L. Martín ◽  
D. Barrado y Navascués ◽  
M. Sterzik ◽  
...  
Keyword(s):  
Brown Dwarfs ◽  
Low Mass Stars ◽  
Infrared Study ◽  
Mid Infrared ◽  
Low Mass

scholarly journals The Evolution of 3He, 4He and D in the Galaxy

2000 ◽  
Vol 198 ◽  
pp. 540-546 ◽  
Author(s):  
Cristina Chiappini ◽  
Francesca Matteucci
Keyword(s):  
Chemical Evolution ◽  
Present Model ◽  
Galactic Disk ◽  
The Sun ◽  
Mixing Process ◽  
Low Mass Stars ◽  
A Value ◽  
The Galaxy ◽  
Low Mass ◽  
Standing Problem

In this work we present the predictions of a modified version of the ‘two-infall model’ (Chiappini et al. 1997 - CMG) for the evolution of 3He, 4He and D in the solar vicinity, as well as their distributions along the Galactic disk. In particular, we show that when allowing for extra-mixing process in low mass stars (M < 2.5 M⊙), as predicted by Charbonnel and do Nascimento (1998), a long standing problem in chemical evolution is solved, namely: the overproduction of 3He by the chemical evolution models as compared to the observed values in the sun and in the interstellar medium. Moreover, we show that chemical evolution models can constrain the primordial value of the deuterium abundance and that a value of (D/H)p < 3 × 10—5 is suggested by the present model. Finally, adopting the primordial 4He abundance suggested by Viegas et al. (1999), we obtain a value for ΔY/ΔZ ≃ 2 and a better agreement with the solar 4He abundance.

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