Substructure in the Circumstellar Disk Around the Young Star AU Microscopii

Science ◽  
2004 ◽  
Vol 305 (5689) ◽  
pp. 1442-1444 ◽  
Author(s):  
M. C. Liu
Keyword(s):  
Young Star ◽  
Circumstellar Disk

scholarly journals A Study of the Young Star V1331 CYG in a Compact Star-Forming Region

1998 ◽  
Vol 11 (1) ◽  
pp. 344-344
Author(s):  
Alisher Hojaev ◽  
Alexander Zheleznyak
Keyword(s):  
Compact Star ◽  
Young Star ◽  
Light Curves ◽  
Circumstellar Disk ◽  
Line Profiles ◽  
Periodic Process ◽  
Dark Cloud ◽  
Star Forming ◽  
T Tauri ◽  
Morphologic Analysis

The peculiar T Tauri type star V1331 Cyg = LkH 120, located in the dark cloud Lynds 984, is a FU Orionis pre-outburst candidate (McMuldroch et al., 1993). This star embedded in circumstellar bright nebulosity is also surrounded by a helix-shaped nebula originated from the star. We obtained a series of speckle images of V1331 Cyg on the standard VBR system on July 18-20, 1994 using the Zeiss 1000 1.0 m telescope of the High Altitude Maydanak Observatory in Uzbekistan. We also used the results of Johnson’s system photometry of V1331 Cyg, made simultaneously at Maydanak Observatory with a 0.6 m reflector. Images were computer processed. Surface photometry of the star and surrounding nebula was made and isophotes were constructed. Fourier analysis of light curves for V1331 Cyg has shown 36.2 day periodic process (Melnikov, priv. comm.) which could be due to the presence of a circumstellar disk. Morphologic analysis revealed a complex fine structure of nebula, consisting of many bright knots and obviously show a jet-like outflow. According to spectral observations (Chavarria K. 1981; Penston & Keavey 1977) the line profiles of V1331 Cyg are P Cyg type only; there are no detections of anti-P Cyg profiles during the last 25 years observations. This indicates a stable mass loss (on average, 10−7M⊙/yr) with mean velocities about −410 km/s.

Millimeter Continuum Image of the Circumstellar Disk around the Young Star Haro 6-5B

2001 ◽  
Vol 552 (1) ◽  
pp. L59-L62 ◽  
Author(s):  
Sozo Yokogawa ◽  
Yoshimi Kitamura ◽  
Munetake Momose ◽  
Yoshiharu Asaki ◽  
Motohide Tamura ◽  
...  
Keyword(s):  
Young Star ◽  
Circumstellar Disk ◽  
Continuum Image

Heavy comet traffic around young star

Nature ◽  
2014 ◽  
Author(s):  
Elizabeth Gibney
Keyword(s):  
Young Star

Young star blows baffling bubble

Nature ◽  
2001 ◽  
Author(s):  
Tom Clarke
Keyword(s):  
Young Star

The circumstellar disk of the Be star 28 (ω) CMa

2003 ◽  
Vol 6 ◽  
pp. 257-257
Author(s):  
S. Štefl ◽  
W. Nowotny-Schipper ◽  
J. Reunanen
Keyword(s):  
Circumstellar Disk ◽  
Be Star

scholarly journals Diffuse γ-ray emission toward the massive star-forming region, W40

2020 ◽  
Vol 639 ◽  
pp. A80
Author(s):  
Xiao-Na Sun ◽  
Rui-Zhi Yang ◽  
Yun-Feng Liang ◽  
Fang-Kun Peng ◽  
Hai-Ming Zhang ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Young Star ◽  
Gas Content ◽  
Large Area ◽  
Stellar Cluster ◽  
Production Region ◽  
Star Forming ◽  
Photon Index ◽  
Young Star Clusters

We report the detection of high-energy γ-ray signal towards the young star-forming region, W40. Using 10-yr Pass 8 data from the Fermi Large Area Telescope (Fermi-LAT), we extracted an extended γ-ray excess region with a significance of ~18σ. The radiation has a spectrum with a photon index of 2.49 ± 0.01. The spatial correlation with the ionized gas content favors the hadronic origin of the γ-ray emission. The total cosmic-ray (CR) proton energy in the γ-ray production region is estimated to be the order of 1047 erg. However, this could be a small fraction of the total energy released in cosmic rays (CRs) by local accelerators, presumably by massive stars, over the lifetime of the system. If so, W40, together with earlier detections of γ-rays from Cygnus cocoon, Westerlund 1, Westerlund 2, NGC 3603, and 30 Dor C, supports the hypothesis that young star clusters are effective CR factories. The unique aspect of this result is that the γ-ray emission is detected, for the first time, from a stellar cluster itself, rather than from the surrounding “cocoons”.

VLA Imaging of the Disk Surrounding the Nearby Young Star TW Hydrae

2000 ◽  
Vol 534 (1) ◽  
pp. L101-L104 ◽  
Author(s):  
D. J. Wilner ◽  
P. T. P. Ho ◽  
J. H. Kastner ◽  
L. F. Rodríguez
Keyword(s):  
Young Star

scholarly journals Double trouble: Gaia reveals (proto)planetary systems that may experience more than one dense star-forming environment

2020 ◽  
Vol 501 (1) ◽  
pp. L12-L17
Author(s):  
Christina Schoettler ◽  
Richard J Parker
Keyword(s):  
Planetary Systems ◽  
Young Star ◽  
Young Stars ◽  
Orion Nebula ◽  
External Effects ◽  
Star Forming ◽  
Star Forming Regions ◽  
Ejection Process ◽  
Runaway Stars

ABSTRACT Planetary systems appear to form contemporaneously around young stars within young star-forming regions. Within these environments, the chances of survival, as well as the long-term evolution of these systems, are influenced by factors such as dynamical interactions with other stars and photoevaporation from massive stars. These interactions can also cause young stars to be ejected from their birth regions and become runaways. We present examples of such runaway stars in the vicinity of the Orion Nebula Cluster (ONC) found in Gaia DR2 data that have retained their discs during the ejection process. Once set on their path, these runaways usually do not encounter any other dense regions that could endanger the survival of their discs or young planetary systems. However, we show that it is possible for star–disc systems, presumably ejected from one dense star-forming region, to encounter a second dense region, in our case the ONC. While the interactions of the ejected star–disc systems in the second region are unlikely to be the same as in their birth region, a second encounter will increase the risk to the disc or planetary system from malign external effects.

The young-star gangs of the Galaxy

2021 ◽  
Vol 5 (7) ◽  
pp. 626-626
Author(s):  
Paul Woods
Keyword(s):  
Young Star ◽  
The Galaxy

scholarly journals On the nature of protostellar H2O masers

1987 ◽  
Vol 122 ◽  
pp. 141-142
Author(s):  
G. M. Rudnitskij
Keyword(s):  
Active Phase ◽  
Young Star ◽  
Line Profiles ◽  
Free Electrons ◽  
Heavy Particles ◽  
Vlbi Observations ◽  
Generation Region ◽  
Star Formation Regions ◽  
Maser Radio ◽  
Two Temperature

Most sources of B2O maser radio emission at 1.35 cm, associated with star formation regions, show strong variability with, sometimes, rapid bursts of emission (see, e.g., Liljeström 1984, Rowland and Cohen 1986, and references therein). A preliminary conclusion on the possible cyclicity of H2O maser variability can be drawn (Lekht et al. 1982, 1983), with a quasiperiod of several years. The “quiet” state of a maser source, with moderate, slowly varying values of the line flux density, turns to the “active” phase with H2O line bursts (Lekht et al. 1983). The H2O maser generation region is probably located in a rotating gas-and-dust disc (torus) around a protostar (or young star). This is pointed to by VLBI observations showing in some sources maser features arranged in an ellipsoidal structure around a common centre (presumably, the protostellar object - see Downes et al. 1979), as well as by symmetrical character of E2O line profiles of many masers (Lekht et al. 1982). As an excitation mechanism for H2O, collisional pumping in two-temperature medium behind a shock front (with hot heavy particles and cold free electrons or vice versa) is widely accepted (Bolgova et al. 1982, Kylafis and Norman 1986).

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