scholarly journals Absolute Parameters of Young Stars: V Puppis

Author(s):  
E Budding ◽  
T Love ◽  
M G Blackford ◽  
T Banks ◽  
M J Rhodes

Abstract New spectrometric data on V Pup are combined with satellite photometry (HIPPARCOS and recent TESS) to allow a revision of the absolute parameters with increased precision. We find: M1 = 14.0±0.5, M2 = 7.3±0.3 (M⊙); R1 = 5.48±0.18, R2 = 4.59±0.15 (R⊙); T1 26000±1000, T2 24000 ±1000 (K), age 5 ±1 (Myr), photometric distance 320 ±10 (pc). The TESS photometry reveals low-amplitude (∼0.002 mag) variations of the β Cep kind, consistent with the deduced evolutionary condition and age of the optical primary. This fact provides independent support to our understanding of the system as in a process of Case A type interactive evolution that can be compared with μ1 Sco. The ∼10 M⊙ amount of matter shed by the over-luminous present secondary must have been mostly ejected from the system rather than transferred, thus taking angular momentum out of the orbit and keeping the pair in relative close proximity. New times of minima for V Pup have been studied and the results compared with previous analyses. The implied variation of period is consistent with the Case A evolutionary model, though we offer only a tentative sketch of the original arrangement of this massive system. We are not able to confirm the previously reported cyclical variations having a 5.47 yr period with the new data, though a direct comparison between the HIPPARCOS and TESS photometry points to the presence of third light from a star that is cooler than those of the close binary, as mentioned in previous literature.

2003 ◽  
Vol 208 ◽  
pp. 427-428
Author(s):  
D. Molteni ◽  
F. Fauci ◽  
G. Gerardi ◽  
M. A. Valenza

Results of 3D numerical simulations of the gas transfer in close binary systems show that it is possible the production of accretion streams having low specific angular momentum in a region close to the accreting star. These streams are mainly placed above the orbital disc. The eventual formation of such bulges and shock heated flows is interesting in the context of advection dominated solutions and for the explanation of spectral properties of the Black Hole candidates in binary systems. We set up a parallelized version of 3D S.P.H. code, using domain decomposion. with increasing spatial resolution around the compact star.


1992 ◽  
Vol 135 ◽  
pp. 41-49
Author(s):  
M. Simon

AbstractOur survey for companions of the young stars now includes 45 systems in the Taurus star-forming region (SFR) and 21 in the Ophiuchus SFR. It is carried out by lunar occultation and imaging in the IR and can identify binaries in the separation range 0″.005 to 10″ in systems brighter than K=10 mag. The observed multiplicity in Taurus is ~1.6 stars/system which is comparable to that of the nearby solarlike stars but corrections for incompleteness increase the multiplicity to at least 1.8.Inner active disks are equally represented among the single and multiple systems. The multiple systems have less massive outer disks than the single systems, but there are significant exceptions. The binary UZ Tau W contains a circumstellar disk or disks of mass ~0.024 M⊙ and size ~13 AU. The quadruple GG Tau system has a remarkably extensive circumbinary disk of mass ~ 0.07M⊙. These mass estimates are comparable to the minimum values required for the proto-planetary disk of the Solar System.The specific angular momenta of the most widely spaced binaries in our sample adjoin the lowest values that can be measured for molecular cloud cores. The actual distributions probably overlap which suggests that the origin of the angular momentum of binaries is in their molecular cloud birthplaces.


2004 ◽  
Vol 215 ◽  
pp. 571-572 ◽  
Author(s):  
S.-C. Yoon ◽  
N. Langer

Classical studies of accreting white dwarfs have assumed spherical symmetry. However, it is believed that in close binary systems the transfered matter carries angular momentum to spin up the accreting star. Here, we present preliminary results of CO white dwarf models which accrete helium rich matter with effects of rotation considered, in the context of the Sub-Chandrasekhar mass scenario for Type Ia supernovae.


Author(s):  
M G Blackford ◽  
A Erdem ◽  
D Sürgit ◽  
B Özkardeş ◽  
E Budding ◽  
...  

2019 ◽  
Vol 879 (1) ◽  
pp. 42 ◽  
Author(s):  
J. A. López-Vázquez ◽  
J. Cantó ◽  
S. Lizano

2007 ◽  
Vol 3 (S243) ◽  
pp. 231-240 ◽  
Author(s):  
Jérôme Bouvier

AbstractStar-disk interaction is thought to drive the angular momentum evolution of young stars. In this review, I present the latest results obtained on the rotational properties of low mass and very low mass pre-main sequence stars. I discuss the evidence for extremely efficient angular momentum removal over the first few Myr of pre-main sequence evolution and describe recent results that support an accretion-driven braking mechanism. Angular momentum evolution models are presented and their implication for accretion disk lifetimes discussed.


2011 ◽  
Vol 418 (4) ◽  
pp. 2812-2812
Author(s):  
by E. Budding ◽  
G. İnlek ◽  
O. Demircan

2017 ◽  
Vol 844 (1) ◽  
pp. 66 ◽  
Author(s):  
Samuel N. Mellon ◽  
Eric E. Mamajek ◽  
Thomas E. Oberst ◽  
Mark J. Pecaut
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