scholarly journals QU Car: a very high luminosity nova-like binary with a carbon-enriched companion

2003 ◽  
Vol 338 (2) ◽  
pp. 401-411 ◽  
Author(s):  
J. E. Drew ◽  
L. E. Hartley ◽  
K. S. Long ◽  
J. van der Walt
Keyword(s):  
High Luminosity ◽  
Very High

scholarly journals Mass loss from early-type stars

1970 ◽  
Vol 36 ◽  
pp. 209-212
Author(s):  
J. B. Hutchings
Keyword(s):  
Mass Loss ◽  
Spectral Type ◽  
Stellar Evolution ◽  
Early Type ◽  
High Luminosity ◽  
Spectroscopic Evidence ◽  
Ob Stars ◽  
Early Type Stars ◽  
Very High ◽  
Hr Diagram

Following the detailed study of four very high luminosity OB stars, a survey has been made for spectroscopic evidence of mass loss in a number of early-type supergiants. A list of spectroscopic criteria is given and the mass loss estimates for 24 stars plotted on the HR diagram. The dependence of the phenomenon on spectral type and luminosity is discussed as well as its significance in terms of stellar evolution.

scholarly journals On possible mass loss from the supergiant RHO Cassiopeia

1981 ◽  
Vol 59 ◽  
pp. 117-118
Author(s):  
M. Boyarchuk
Keyword(s):  
Mass Loss ◽  
Crimean Astrophysical Observatory ◽  
High Luminosity ◽  
Very High

The supergiant Rho Cas F8Ia has a very high luminosity. Astronomers have payed attention to this star in August 1946, when its by its brightness had dropped from 4.2 to 6.2. The systematic spectrographic observations of Rho Cas are beeing carried out at the Crimean Astrophysical Observatory since 1965. No large light variations were observed during that time.

scholarly journals Discovery of new bright ULIRGs from the IRAS PSC/FSC Combined Catalogue

2018 ◽  
Vol 2 (1) ◽  
pp. 13-20
Author(s):  
G. A. Mikayelyan ◽  
◽  
A. M. Mickaelian ◽  
H. V. Abrahamyan ◽  
G. M. Paronyan ◽  
...  
Keyword(s):  
Star Formation ◽  
Early Universe ◽  
Formation Processes ◽  
Direct Impact ◽  
High Luminosity ◽  
Nuclear Activity ◽  
Active Star ◽  
Multiple Structure ◽  
Activity Types ◽  
Very High

High-luminosity IR galaxies (LIRGs, ULIRGs, and HLIRGs) are important for studies related to star-formation processes in the early Universe, as their luminosity allows to detect them at large distances. High IR indicates active star-formation and often starburst processes, which is typical to HII (starburst, SB) and AGN. An interesting question is whether the starburst triggers AGN or vice versa or there is no direct impact. Considering that very often such objects manifest double and multiple structure, it is also interesting to investigate the interrelationship between the SB, nuclear activity and interactions or merging. We have analyzed the IRAS PSC/FSC Combined Catalogue for search for new bright ULIRGs. By means of the SDSS DR14 data, namely redshifts for those objects having spectroscopy, we have calculated the IR luminosities and have found 114 very high-luminosity IR galaxies; 107 ULIRGs and 7 HLIRGs. Among them, 48 new ULIRGs and 7 new HLIRGs have been discovered. These objects have been studied by SDSS color-color, luminosity-redshift and other diagrams. Further studies will include the content of the sample for activity types and other available data.

scholarly journals Water masers and the near-stellar environment in YSOs

2002 ◽  
Vol 206 ◽  
pp. 27-34
Author(s):  
Mark J. Claussen
Keyword(s):  
Main Sequence ◽  
Very Long Baseline Interferometry ◽  
Angular Resolution ◽  
Young Stellar Objects ◽  
High Angular Resolution ◽  
High Luminosity ◽  
Stellar Objects ◽  
Long Baseline ◽  
Water Masers ◽  
Very High

I present a review of observations of water masers, in particular very high angular resolution of water masers using Very Long Baseline Interferometry, with which it is possible to probe the environment of young stellar objects and forming stars within only a few A.U. of the protostar, its accretion disk, and therefore the base of outflowing material. Although reference is made to some high-luminosity sources, the main thrust of the review are the water masers found toward forming objects whose mass and luminosity will be approximately that of the Sun when they reach the main sequence.

scholarly journals 2.2. The stellar content of the Quintuplet cluster

1998 ◽  
Vol 184 ◽  
pp. 61-62 ◽  
Author(s):  
Donald F. Figer ◽  
Ian S. McLean ◽  
Mark Morris ◽  
Francisco Najarro
Keyword(s):  
Molecular Cloud ◽  
Main Sequence ◽  
Cool Temperature ◽  
Stellar Content ◽  
Late Type ◽  
High Luminosity ◽  
Carbon Stars ◽  
M 10 ◽  
Cluster Properties ◽  
Very High

The Quintuplet cluster contains over two dozen post main sequence descendants of massive O-stars, including Wolf-Rayet and OBI stars.The five Quintuplet-proper members (QPMs) may be dusty late-type Wolf-Rayet carbon stars (DWCLs), and the Pistol star may have a very high luminosity, ≈ 106.7±0.5 L⊙. Coupled with its rather cool temperature, 12–23 kK, the Pistol Star is well in violation of the Humphreys–Davidson limit. We argue that the surrounding “Pistol” nebula was ejected from the star a few thousand years ago.The cluster stars imply the following approximate cluster properties: tage ∼ 2 to 7 Myrs, M ∼ 104 M⊙, L ∼ 107.3±0.2 L⊙, and NLy,c > 1049.9 s−1. The “Sickle” (G0.18–0.04) radio feature and the mid-IR ring (seen in MSX images) may naturally be explained by the presence of a young cluster and a nearby molecular cloud.

scholarly journals Formation of Bi-Polar Spiral Features in Galactic Nuclei

1989 ◽  
Vol 134 ◽  
pp. 488-489
Author(s):  
Paris Pişmiş ◽  
Edmundo Moreno
Keyword(s):  
Hot Spots ◽  
Galactic Nuclei ◽  
Short Exposure ◽  
H Ii Regions ◽  
High Luminosity ◽  
High Resolution Imagery ◽  
The Galaxy ◽  
Double Spiral ◽  
Scale Structures ◽  
Very High

In earlier communications we have called attention to the existence of very tight spiral formations in the nuclei of some galaxies, particularly of the early type barred spirals, proposing a mechanism for their formation (Pişmiş and Moreno 1984). These kiloparsec-scale structures are loosely termed “rings” but their overall morphology suggests strongly that the image is a tightly wound double spiral usually delineated by knots of emitting material, “hot-spots”. A striking characteristic of these spirals is their very high luminosity compared to the outer regions of the galaxy. 26 galaxies with “nuclear” spirals are listed by Buta, thesis. A systematic search with short exposure high resolution imagery may reveal many more nuclear spirals. NGC 4736 (Sb) though not a barred spiral has a well defined inner spiral delineated by very luminous H II regions.

Collision Technologies for Circular Colliders

2014 ◽  
Vol 07 ◽  
pp. 207-224 ◽  
Author(s):  
Eugene Levichev
Keyword(s):  
Magnetic Field ◽  
Particle Physics ◽  
Scientific Instruments ◽  
High Luminosity ◽  
Collision Point ◽  
Circular Particle ◽  
Key Technologies ◽  
Technological Developments ◽  
Vacuum Systems ◽  
Very High

For several decades already, particle colliders have been essential tools for particle physics. From the very beginning, such accelerators have been among the most complicated scientific instruments ever built, including a number of innovative technological developments. Examples are ultrahigh vacuum systems, magnets with a very high magnetic field, and equipment for sub-ns synchronization and sub-mm precision alignment of equipment inside multi-km underground tunnels. Some key technologies are related to the focusing of the beam down to a scale of sub-μm at the collision point to obtain high luminosity. This review provides an overview of collision concepts and technologies for circular particle colliders, starting from the first ideas. In particular, it discusses such novel schemes and related technologies as crab waist collision and round beam collision.

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