Non-thermal radiation from a runaway early-type star

2012 ◽  
Author(s):  
María Victoria del Valle ◽  
Gustavo E. Romero ◽  
Michaël De Becker
Keyword(s):  
Thermal Radiation ◽  
Type Star ◽  
Early Type ◽  
Early Type Star

scholarly journals An “A star” on an M star during a flare within a flare

2010 ◽  
Vol 6 (S273) ◽  
pp. 261-264 ◽  
Author(s):  
Adam F. Kowalski ◽  
Suzanne L. Hawley ◽  
Jon A. Holtzman ◽  
John P. Wisniewski ◽  
Eric J. Hilton
Keyword(s):  
Hot Spot ◽  
Type Star ◽  
Early Type ◽  
M Dwarfs ◽  
Early Type Star ◽  
Balmer Lines ◽  
Optical Continuum ◽  
M Dwarf ◽  
Rise Phase ◽  
Optical Flare

AbstractM dwarfs produce explosive flare emission in the near-UV and optical continuum, and the mechanism responsible for this phenomenon is not well-understood. We present a near-UV/optical flare spectrum from the rise phase of a secondary flare, which occurred during the decay of a much larger flare. The newly formed flare emission resembles the spectrum of an early-type star, with the Balmer lines and continuum in absorption. We model this observation phenomenologically as a temperature bump (hot spot) near the photosphere of the M dwarf. The amount of heating implied by our model (ΔTphot ~ 16,000 K) is far more than predicted by chromospheric backwarming in current 1D RHD flare models (ΔTphot ~ 1200 K).

scholarly journals The polarization mode of the auroral radio emission from the early-type star HD 142301

2018 ◽  
Vol 482 (1) ◽  
pp. L4-L8 ◽  
Author(s):  
P Leto ◽  
C Trigilio ◽  
L M Oskinova ◽  
R Ignace ◽  
C S Buemi ◽  
...  
Keyword(s):  
Radio Emission ◽  
Type Star ◽  
Polarization Mode ◽  
Early Type ◽  
Early Type Star

scholarly journals A bright early-type star in the halo of NGC 253: Runaway or in situ formation?

2003 ◽  
Vol 400 (1) ◽  
pp. 137-143 ◽  
Author(s):  
F. Comerón ◽  
A. E. Gómez ◽  
J. Torra
Keyword(s):  
Type Star ◽  
Early Type ◽  
Early Type Star ◽  
In Situ Formation

scholarly journals The Shape of the Interstellar Reddening Curve

1965 ◽  
Vol 7 ◽  
pp. 27-37
Author(s):  
Anne B. Underhill ◽  
Gordon A. H. Walker
Keyword(s):  
Spectral Type ◽  
Intensity Distribution ◽  
Spectral Intensity ◽  
Type Star ◽  
Early Type ◽  
The Earth ◽  
Early Type Star ◽  
Sensitivity Factors ◽  
Interstellar Material ◽  
The Difference

When the Observed Spectral Intensity Distribution of an early-type star has been freed from the distortions caused by absorption in the Earth's atmosphere and by instrumental sensitivity factors, it is a measure of the true spectral intensity distribution of the star and of the modifications to that distribution caused by the interstellar material between the Earth and the star. Thus, if one knew the true intensity distribution from the star, one could derive the shape of the interstellar reddening curve. In practice it is customary to compare the intensity distributions of pairs of stars of apparently the same spectral type, within the errors of classification, but which suffer different amounts of reddening, and to attribute the difference to interstellar reddening. In this way one can determine the shape of the interstellar reddening curve.

scholarly journals Photospheric Variability in EUVE Observations of β Canis Majoris (B1 II-III)

1996 ◽  
Vol 152 ◽  
pp. 389-394 ◽  
Author(s):  
David H. Cohen ◽  
Joseph J. MacFarlane ◽  
Joseph P. Cassinelli
Keyword(s):  
Temperature Change ◽  
Type Star ◽  
Early Type ◽  
Lyman Continuum ◽  
Early Type Star ◽  
Pulsation Component

The only pulsating early-type star observed by EUVE, the β Cephei variable β CMa, displays periodic variability in its Lyman continuum which is basically consistent with the long-known optical and UV variability. The amplitude of the primary pulsation component is significantly larger in the EUV than in the optical or UV. This is consistent with a temperature change being the explanation for the variability. It is notable that the pulsations have been detected in the Lyman continuum because this part of the spectrum is formed in a much higher layer of the photosphere than either the UV or optical continua.

scholarly journals A RARE EARLY-TYPE STAR REVEALED IN THE WING OF THE SMALL MAGELLANIC CLOUD

2012 ◽  
Vol 753 (2) ◽  
pp. 173 ◽  
Author(s):  
C. J. Evans ◽  
R. Hainich ◽  
L. M. Oskinova ◽  
J. S. Gallagher III ◽  
Y.-H. Chu ◽  
...  
Keyword(s):  
Magellanic Cloud ◽  
Type Star ◽  
Early Type ◽  
Small Magellanic Cloud ◽  
Early Type Star

scholarly journals S106-IRS4: A Star Loosing Mass in the Centre of a Bipolar Nebula

1987 ◽  
Vol 115 ◽  
pp. 359-360
Author(s):  
M. Felli ◽  
M. Simon
Keyword(s):  
Mass Loss ◽  
Radio Source ◽  
Type Star ◽  
Narrow Gap ◽  
Early Type ◽  
Bipolar Structure ◽  
Near Ir ◽  
Early Type Star ◽  
Photometric Measurements

S106-IRS4 is the brightest near IR source associated with the S106 bipolar nebula. It is located exactly at the centre of the bipolar structure, inside the narrow gap of emission between the two radio lobes. It is also a weak radio source. An analysis of the near IR photometric measurements and of the radio fluxes suggests the presence of an ionized envelope produced by mass loss of the early type star which is responsible for the ionization of the nebula (Felli et al. 1984).

scholarly journals A bright early-type star in the halo of NGC 253: Runaway or in situ formation?

2003 ◽  
Vol 402 (1) ◽  
pp. 181-181
Author(s):  
F. Comerón ◽  
A. E. Gómez ◽  
J. Torra
Keyword(s):  
Type Star ◽  
Early Type ◽  
Early Type Star ◽  
In Situ Formation
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