Results 21 to 30 of about 198,420 (284)

Reddening-Free Q Parameters to Classify B-Type Stars with Emission Lines

Galaxies, 2023
The emission-line B-type stars constitute a heterogeneous group. Many of these stars show similar optical spectroscopic features and color indices, making it difficult to classify them adequately by means of photometric and spectroscopic techniques. Thus,
Yael Aidelman, Lydia Sonia Cidale
doaj   +1 more source

Non-emission-line young stars of intermediate mass [PDF]

Monthly Notices of the Royal Astronomical Society, 2002
7 pages, 5 figures, accepted by ...
Manoj, P., Maheswar, G., Bhatt, H. C.
openaire   +2 more sources

Survey of X-Rays from Massive Stars Observed at High Spectral Resolution with Chandra

The Astrophysical Journal, 2023
Identifying trends between observational data and the range of physical parameters of massive stars is a critical step to the still-elusive full understanding of the source, structure, and evolution of X-ray emission from the stellar winds, requiring a ...
Pragati Pradhan, David P. Huenemoerder, Richard Ignace, Joy S. Nichols, A. M. T. Pollock   +4 more
doaj   +1 more source

The nature of LINER galaxies: Ubiquitous hot old stars and rare accreting black holes [PDF]

, 2013
Galaxies, which often contain ionised gas, sometimes also exhibit a so-called low-ionisation nuclear emission line region (LINER). For 30 years this was attributed to a central mass-accreting supermassive black hole (AGN) of low luminosity, making LINER ...
Alves, J., collaboration, the CALIFA, Falcón-Barroso, J., Fernandes, R. Cid, Galbany, L., García-Benito, R., Husemann, B., Jahnke, K., Kennicutt, R. C., Lyubenova, M., Marino, R. A., Masegosa, J., Mast, D., Márquez, I., Pasquali, A., Singh, R., Sánchez, S. F., van de Ven, G., Walcher, J., Wild, V., Wisotzki, L., Ziegler, B.   +21 more
core   +2 more sources

High Resolution Emission Line Profiles in Blue Luminous Stars [PDF]

International Astronomical Union Colloquium, 1989
Emission lines are often observed in high luminosity stars and provide evidence of the presence of extended stellar envelopes. Ha is the most frequently observed across the H-R diagram, but lines of Hel or Fell are also found in emission in these stars. They could be used as diagnostics of the structure of their outer atmospheres and winds.
Bandiera R, Focardi P, ALTAMORE, Aldo, Rossi C, Stahl O.   +4 more
openaire   +2 more sources

Studying the UV Mg II Resonance Lines in 20 Be Stars

Open Astronomy, 2011
Using the GR model, we analyze the UV Mg II resonance lines in the spectra of 20 Be stars of different spectral subtypes, in order to detect the presence of satellite or discrete absorption components. The values of some physical parameters – rotational,
Antoniou A., Stathopoulos D., Danezis E., Lyratzi E.   +3 more
doaj   +1 more source

Symbiotic stars and other Hα emission-line stars towards the Galactic bulge★ [PDF]

Monthly Notices of the Royal Astronomical Society, 2013
Symbiotic stars are interacting binaries with the longest orbital periods and their multi-component structure makes them rich astrophysical laboratories. The accretion of a high mass loss rate red giant wind on to a white dwarf (WD) makes them promising Type Ia supernovae (SNe Ia) progenitors.
B. Miszalski, J. Mikolajewska, A. Udalski   +2 more
openaire   +2 more sources

Emission-line stars discovered in the UKST H-alpha survey of the Large Magellanic Cloud; Part 1: Hot stars

, 2012
We present new, accurate positions, spectral classifications, radial and rotational velocities, H-alpha fluxes, equivalent widths and B,V,I,R magnitudes for 579 hot emission-line stars (classes B0 - F9) in the Large Magellanic Cloud which include 469 new
Acke, Andrews, Andrillat, Beaulieu, Bjorkman, Bjorkman, Bland-Hawthorn, Bohannan, Bowyer, Butler, Böhm, Böhm, Cassinelli, Cohen, Corcoran, Cranmer, Dachs, Dachs, Draper, Feast, Frew, Gordon, Grebel, Grebel, Gullbring, Hamann, Hambly, Hanuschik, Hanuschik, Hartigan, Hartmann, Henize, Henyey, Herbig, Hernández, Hillenbrand, Hubert, Hubert-Delplace, Hubrig, Hughes, Hummel, Hutsemékers, Jacoby, Jacoby, Jaschek, Jaschek, Kaler, Keller, Keller, Keller, Kontizas, Kurtz, Königl, Lada, Larson, Le Borgne, Lewis, Lindsay, Lindsay, Lumb, Melchior, Mennickent, Miroshnichenko, Morgan, Murai, Muzerolle, Muzerolle, Muzerolle, Olsen, Parker, Parker, Parker, Pasquini, Pickles, Poeckert, Porter, Porter, Quentin A. Parker, Quirrenbach, Reid, Reid, Reid, Reid, Rivinius, Rivinius, Rohlfs, Sabogal, Schwering, Silaj, Silva, Skrutskie, Slettebak, Stanghellini, Struve, Szymański, Tonry, Townsend, Townsend, Turnshek, Tycner, Uchida, Udalski, Underhill, Van Winckel, Viera, Wade, Warren A. Reid, Waters, Wisniewski   +108 more
core   +1 more source

High-resolution, H band Spectroscopy of Be Stars with SDSS-III/APOGEE: I. New Be Stars, Line Identifications, and Line Profiles [PDF]

, 2014
APOGEE has amassed the largest ever collection of multi-epoch, high-resolution (R~22,500), H-band spectra for B-type emission line (Be) stars. The 128/238 APOGEE Be stars for which emission had never previously been reported serve to increase the total ...
Beaton, Rachael, Bizyaev, Dmitry, Brewington, Howard, Brinkmann, J., Burton, Adam, Chojnowski, S. Drew, Damke, Guillermo, Ebelke, Garrett, Eikenberry, Steve, Frinchaboy, Peter M., Hall, Matthew, Hasselquist, Sten, Holtzman, Jon A., Kinemuchi, Karen, Majewski, Steven R., Malanushenko, Elena, Malanushenko, Viktor, Marchante, Moses, Meszaros, Szabolcs, Nidever, David, Oravetz, Daniel, Pan, Kaike, Schneider, Donald P., Shetrone, Matthew, Simmons, Audrey, Whelan, David G., Wilson, John, Wisniewski, John P., Zasowski, Gail   +28 more
core   +3 more sources

Star Formation in the Ultraviolet

Galaxies, 2020
With the launch of JWST and the upcoming installation of extremely large telescopes, the first galaxies in our Universe will finally be revealed.
Jorick S. Vink
doaj   +1 more source