Results 1 to 10 of about 451,430 (273)

Massive pre-main sequence stars in M17 [PDF]

Proceedings of the International Astronomical Union, 2016
The formation process of massive stars is still poorly understood. Massive young stellar objects (mYSOs) are deeply embedded in their parental clouds, they are rare and thus typically distant, and their reddened spectra usually preclude the determination
Bik, Arjan, de Koter, Alex, Ellerbroek, Lucas E., Kaper, Lex, Ochsendorf, Bram B., Ramírez-Agudelo, Oscar H., Ramírez-Tannus, María Claudia, Sana, Hugues, Tramper, Frank   +8 more
core   +8 more sources

Simulations of Stellar Collisions Involving Pre-Main Sequence Stars [PDF]

Astrophys.J. 627 (2005) 277-285, 2005
In this paper, we present the results of smoothed particle hydrodynamic (SPH) simulations of collisions between pre-main sequence stars and a variety of other kinds of stars. Simulations over a range of impact parameters and velocities were performed. We find that pre-main sequence stars tend to ``wrap themselves'' around their impactor. We discuss the
Alison Sills, Bate M. R., Daniel Laycock, Siess L.   +3 more
arxiv   +6 more sources

Rotation and activity of pre-main-sequence stars [PDF]

The Astrophysical Journal, 2007
We present a study of rotation (vsini) and chromospheric activity (Halpha EW) based on an extensive set of high-resolution optical spectra obtained with MIKE on the 6.5m Magellan Clay telescope.
Alexander Scholz, Alexis Brandeker, Baraffe I., Chabrier G., Delfosse X., Guenther E. W., Hodgkin S. T., Jaime Coffey, Peat D. W., Queloz D., Ray Jayawardhana, Reid N., Strauss F. M.   +12 more
core   +6 more sources

IRAC Observations of Taurus Pre-Main Sequence Stars [PDF]

The Astrophysical Journal, 2005
We present infrared photometry obtained with the IRAC camera on the Spitzer Space Telescope of a sample of 82 pre-main sequence stars and brown dwarfs in the Taurus star-forming region. We find a clear separation in some IRAC color-color diagrams between
Giovanni Fazio, Kevin Luhman, Lee Hartmann, Lori Allen, Lucas P. W., Lynden-Bell D., Monin J.-L., Nuria Calvet, Paola D’Alessio, Ramiro Franco‐Hernandez, S. T. Megeath   +10 more
core   +6 more sources

Timescale of Mass Accretion in Pre-Main-Sequence Stars [PDF]

Astronomy and Astrophysics, 2009
We present initial result of a large spectroscopic survey aimed at measuring the timescale of mass accretion in young, pre-main-sequence stars in the spectral type range K0 - M5.
Allen, Barrado y Navascués, Basri, Beristain, Boss, Boss, Bouwman, Briceño, Briceño, Caballero, Carpenter, Clarke, D. Fedele, Dahm, Damjanov, Flaherty, Forbes, Haisch, Haisch, Hartmann, Hartmann, Herczeg, Hernández, Horne, J. M. Oliveira, Jayawardhana, Jeffries, Kharchenko, Lada, Luhman, M. E. van den Ancker, Mentuch, Mohanty, Moraux, Natta, Oliveira, Oliveira, Park, Pollack, R. Jayawardhana, Sana, Schmidt, Sicilia-Aguilar, Sicilia-Aguilar, Sicilia-Aguilar, Th. Henning, Thommes, White, Wilking, Winston, Zapatero Osorio, Zuckerman   +51 more
core   +6 more sources

Accretion in the Rho-Oph pre-main sequence stars [PDF]

Astronomy & Astrophysics, 2006
The aim of this paper is to provide a measurement of the mass accretion rate in a large, complete sample of objects in the core of the star forming region Rho-Oph.
A. Natta, Alexander, Balbus, Barsony, Barsony, Bontemps, Calvet, D'Antona, Doppmann, Feigelson, Greene, Gullbring, Hartmann, Hueso, Imanishi, Johns-Krull, Kenyon, L. Testi, Luhman, Meyer, Muzerolle, Muzerolle, Muzerolle, Muzerolle, Muzerolle, Natta, Natta, Ozawa, Preibisch, Ratzka, S. Randich, Shakura, Siess, Wallace, White, White, Wilking   +36 more
core   +7 more sources

Pre-main sequence stars in the Cepheus flare region [PDF]

The Astrophysical Journal Supplement Series, 2009
We present results of optical spectroscopic and BVR_CI_C photometric observations of 77 pre-main sequence (PMS) stars in the Cepheus flare region. A total of 64 of these are newly confirmed PMS stars, originally selected from various published candidate ...
Bally, Balog, Barrado y Navascués, Beltrán, Berkhuijsen, Cieza, Cutri, D'Alessio, Dahm, Dobashi, Dullemond, Eiroa, Eiroa, Eredics, Eric E. Mamajek, Evans, Friedemann, Glass, Gullbring, Gutermuth, Gutermuth, Gutermuth, Herbig, Herczeg, Hester, Jaschek, Joint IRAS Science W. G., Kirk, Kun, Kun, Kun, Kun, Lada, Lee, Lee, Meehan, Miranda, Miranda, Moshir, Muzerolle, Mária Kun, Ogura, Padgett, Page, Palla, Preibisch, Reipurth, Robert A. Gutermuth, Rosino, Scott J. Kenyon, Semkov, Semkov, Shevchenko, Simon, Spoelstra, Straizys, Yonekura, Zdanavičius, Zoltán Balog, Ábrahám   +59 more
core   +6 more sources

The Ages of Pre-main-sequence Stars [PDF]

Monthly Notices of the Royal Astronomical Society, 1998
The position of pre-main-sequence or protostars in the Hertzsprung--Russell diagram is often used to determine their mass and age by comparison with pre-main-sequence evolution tracks.
Alexander, Anders, Baraffe, Bell, Boss, Carpenter, Christopher A. Tout, Cohen, D'Antona, Eggleton, Eggleton, Eggleton, Gullbring, Hartmann, Hartmann, Hayashi, Henyey, Hillenbrand, Ian A. Bonnell, Iglesias, Kenyon, Kenyon, Kroupa, Larson, Larson, Lin, Low, Mario Livio, Mercer-Smith, Muzerolle, Palla, Pols, Rees, Rubin, Siess, Siess, Stahler, Stahler, Stahler, Stahler, Stahler, Tout, Tout, Warner, Winkler, Woolley   +45 more
core   +4 more sources

The Pre--Main-Sequence of A-type stars [PDF]

Proceedings of the International Astronomical Union, 2004
Young A-type stars in the pre--main-sequence (PMS) evolutionary phase are particularly interesting objects since they cover the mass range (1.5-4 solar ma sses) which is most sensitive to the internal conditions inherited during the protostellar phase ...
Marconi, Marcella, Palla, Francesco
core   +4 more sources

The Instability Strip for Pre--Main-Sequence Stars [PDF]

The Astrophysical Journal, 1998
We investigate the pulsational properties of Pre--Main-Sequence (PMS) stars by means of linear and nonlinear calculations. The equilibrium models were taken from models evolved from the protostellar birthline to the ZAMS for masses in the range 1 to 4 ...
Baade D., Breger M., Catala C., Francesco Palla, Gahm G. F., Grinin V. P., Kurtz D. W., Marcella Marconi, van den Ancker M. E., van den Ancker M. E.   +9 more
core   +6 more sources