Results 41 to 50 of about 72 (61)

Spectroscopic Observations of the GALEX Nearby Young Star Survey Sample. I. Nearby Moving Group Candidates

The Open Journal of Astrophysics
The GALEX Nearby Young Star Search (GALNYSS) yielded the identification of more than 2000 late-type stars that, based on their ultraviolet and infrared colors and pre-Gaia proper motions, are potentially of ...
Navya Nagananda, Laura Vican, Ben Zuckerman, David Rodriguez, Alexander Binks, Joel Kastner   +5 more
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Chandra HETG X-Ray Spectra and Variability of π Aqr, a γ Cas-type Be Star

The Astrophysical Journal Letters
High-resolution X-ray spectra of π Aqr, a γ Cas-type star, obtained with the Chandra/HETG spectrometer, revealed emission lines of H-like ions of Mg, Si, S, and Fe; a strong, hard continuum; and a lack of He-like ions, indicating the presence of very hot
David P. Huenemoerder, Pragati Pradhan, Claude R. Canizares, Sean Gunderson, Richard Ignace, Joy S. Nichols, A. M. T. Pollock, Norbert S. Schulz, Dustin K. Swarm, José M. Torrejón   +9 more
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New constraints on the binary system HD 327083 and its gaseous and dusty environments

Astronomy & Astrophysics
Context. Binary systems with circumbinary molecular and dust rings are of great interest because they provide insights into the dynamics and evolution of stellar systems and the chemistry of the surrounding material. Aims.
Cidale L., Marchiano P., Kraus M., Andruchow I., Arias M. L., Curé M., Borges Fernandes M., Aidelman Y., Torres A. F., Araya I., Maravelias G., Zorec J., Cochetti Y., Panei J.   +13 more
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A Time-dependent Spectral Analysis of γ Cassiopeiae

The Astrophysical Journal
We investigated the temporal and spectral features of γ Cassiopeiae’s X-ray emission within the context of the white dwarf (WD) accretion hypothesis. We find that the variabilities present in the X-ray data show two different signals, one primarily due ...
Sean J. Gunderson, David P. Huenemoerder, José M. Torrejón, Dustin K. Swarm, Joy S. Nichols, Pragati Pradhan, Richard Ignace, Hans Moritz Guenther, A. M. T. Pollock, Norbert S. Schulz   +9 more
doaj   +1 more source

A Spectroscopic Survey of Metal-poor OB Stars in Local Dwarf Galaxy NGC 3109

The Astrophysical Journal
As JWST uncovers increasingly strong evidence that metal-poor, massive stars in early galaxies dominated reionization, observational constraints on the properties of such stars are more relevant than ever before.
Abby Mintz, O. Grace Telford, Evan N. Kirby, John Chisholm, Kristen B. W. McQuinn, Danielle A. Berg   +5 more
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The Fate of the Interstellar Medium in Early-type Galaxies. V. Active Galactic Nucleus Feedback from Optical Spectral Classification

The Astrophysical Journal Supplement Series
Quenching of star formation plays a fundamental role in galaxy evolution. This process occurs due to the removal of the cold interstellar medium (ISM) or stabilization against collapse, so that gas cannot be used in the formation of new stars.
Oleh Ryzhov, Michał J. Michałowski, J. Nadolny, J. Hjorth, A. Leśniewska, M. Solar, P. Nowaczyk, C. Gall, T. T. Takeuchi   +8 more
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Early Shock Cooling Observations and Progenitor Constraints of Type IIb Supernova SN 2024uwq

The Astrophysical Journal Letters
We present early multiwavelength photometric and spectroscopic observations of the Type IIb supernova SN 2024uwq, capturing its shock-cooling emission phase and double-peaked light-curve evolution.
Bhagya M. Subrayan, David J. Sand, K. Azalee Bostroem, Saurabh W. Jha, Aravind P. Ravi, Michaela Schwab, Jennifer E. Andrews, Griffin Hosseinzadeh, Stefano Valenti, Yize Dong, Jeniveve Pearson, Manisha Shrestha, Lindsey A. Kwok, Emily Hoang, Jeonghee Rho, Seong Hyun Park, Sung-Chul Yoon, T. R. Geballe, Joshua Haislip, Daryl Janzen, Vladimir Kouprianov, Darshana Mehta, Nicolás Meza Retamal, Daniel E. Reichart, Moira Andrews, Joseph Farah, Megan Newsome, D. Andrew Howell, Curtis McCully   +28 more
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A Spectroscopic and Photometric Study of MWC 342 and Its B[e] Phenomenon over the Last 40 Years

Galaxies
MWC 342 (V1972 Cyg) was discovered nearly 90 years ago as an early-type emission-line star. It was among the first hot stars whose strong infrared excess was detected in the early 1970s.
Aigerim Zh. Akniyazova, Anatoly S. Miroshnichenko, Sergey V. Zharikov, Hans Van Winckel, Nadine Manset, Ashish Raj, Stephen Drew Chojnowski, Serik A. Khokhlov, Inna V. Reva, Raushan I. Kokumbaeva, Chingis T. Omarov, Konstantin N. Grankin, Aldiyar T. Agishev, Nadezhda L. Vaidman   +13 more
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The HST Nondetection of SN Ia 2011fe 11.5 yr after Explosion Further Restricts Single-degenerate Progenitor Systems

The Astrophysical Journal
We present deep Hubble Space Telescope imaging of the nearby Type Ia supernova (SN Ia) 2011fe obtained 11.5 yr after explosion. No emission is detected at the SN location to a 1 σ (3 σ ) limit of F555W > 30.2 (29.0) mag, or equivalently M _V > 1.2 (−0.1)
M. A. Tucker, B. J. Shappee
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The Radiowave Hunt for Young Stellar Object Emission and Demographics (RADIOHEAD): A Radio Luminosity–Spectral Type Dependence in Taurus–Auriga YSOs

The Astrophysical Journal
We measure the radio continuum fluxes at the locations of all Gaia-confirmed members of Taurus–Auriga using Karl G. Jansky Very Large Array Sky Survey data (VLASS; 2–4 GHz, σ _VLASS  ~ 110–140 μ Jy, 2 $\mathop{.}\limits^{\unicode{x02033}}$ 5 resolution ...
Ramisa Akther Rahman, Joshua Bennett Lovell, Eric W. Koch, David J. Wilner, Sean M. Andrews, Kristina Monsch, Dan Ha   +6 more
doaj   +1 more source