In two previous papers we investigated in detail the formation of Hydrogen lines in high pressure dMe stellar chromospheres, constraining the possible structures over a two orders of magnitude pressure range. ... We found that when decreasing the transitoin region presure (i.e. the chromospheric temperature gradient), the Balmer lines change rapidly from emission to strong absorption, then the profiles weaken and become narrower until they disappear totally (zero H$_{\alpha}$ stars). ...

Next: Infrared Data Up: Contents Previous: Optical Photometry . ... For example, one method is to derive the spectral energy distribution (SED) for a target star and compare it to the SED of a dereddened standard star. ... Temperature can be determine via the B - V color (Gilliland 1985): . ... The results produced small extinctions to the background stars of between A and A . ... The most accurate extinction calculation requires both IR and spectral data. Infrared Data . Spectroscopic Data . ...

home education > activities . ... Quick math activity that asks students to calculate scale models of a binary star system with a black hole in it. [h] . ... Students use a radiometer and a light bulb with a dimmer switch to make connections between the temperature, color, and radiation output of a star. ... This demonstration, similar to the above, from the Exploratorium Snack-book of science activities, lets students demonstrate how molecules scatter light and change the colors of the beam. [m,h] . ...

... 172 ] Briefly, the count rate at the detector from a source at a redshift z is . ... Figure 55 shows the ``Green functions'' for the double compact binary merging rate   evolution assuming no collapse anisotropy. ... Another way that diverse peculiarities in the - distribution induced by the sources evolution could arise is connected with a possible non-monotonic character of the star formation rate in galaxies. ... 22 ] Figure  56 shows two-dimensional cuts through the parameter space. ...

Context. Thermal emission by stochastically heated dust grains (SHGs) plays an important role in the radiative transfer (RT) problem for a dusty medium. ... Aims: We define an appropriate problem for benchmarking dust emissivity calculations in the context of RT simulations, specifically including the emission from SHGs. ... It also includes a series of analytically defined radiation fields to which the dust population is to be exposed and instructions for the desired output. ...

... The hotter the gas, the faster they move, and the more energy each of them holds. The free ions and electrons in a plasma behave the same way. Knowing the temperature of the high atmosphere of Earth, or that of the Sun, we can calculate energies expected of ions and electrons found there. However, ions and electrons actually observed in space are often much , much more energetic, and may move at a respectable fraction of the velocity of light (300,000 km/sec or 186,000 miles/sec). ...

... The BM effect causes low-luminosity blazars (particularly BL Lacs) to be missed in surveys because the apparent luminosity of the non-thermal nuclear source does not exceed that of the host galaxy by a large factor. ... Browne (1995). ... In addition to these objects, a large fraction of the newly-identified BL Lacs in our sample (10 of 22; see Table 5) have been so classified only by virtue of our usage of the expanded March? et al. (1996) definition of the BL Lac class. ... 1996). ...

Spectropolarimetry and modeling of Galactic Wolf-Rayet star WR156 O LGA M A RY E VA Special Astrophysical Observatory RAS; olga.maryeva@gmail.com For the first time spectropolarimetric observations of Wolf-Rayet star WR156 (WN8h sub-class) were conducted. ... This polarization is, most probably, has an interstellar origin, as its magnitude and orientation are similar to the ones of field stars. ... By its parameters WR156 is similar to other WN8h stars, displaying the line effect. ...

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... Fitting the observed dependence includes calculations of the polarization cross-sections averaged over particles orientation and size distribution, their normalization and the comparison of obtained dependencies with Serkowski's curve representing observational data for a chosen star. ... Variations of the polarization factors with wavelength are shown in Fig. 16 for homogeneous spheroidal particles with PF orientation. ... The distinction between prolate and oblate spheroids is also clearly seen. ...

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