He described it as probably 25,000 times fainter than the sun and very blue, its color like that of a B-type star
Mark Wagner (University of Arizona) and others using the 6.5-meter telescope at the MMT Observatory at Mount Hopkins, Arizona, have revealed that V838 Mon is a binary system, consisting of a hot B-type star
and, now, a very cool red supergiant.
That makes it hard to know if the blame lies with a particular protostar such as IRc2 or the Becklin-Neugebauer object, which is probably an ordinary B-type star
reddened by thick dust.
This dim object surrounds the magnitude-5.7 B-type star
Earlier studies suggested that such fast-moving stars are O- and B-type stars
and can only live for tens of millions of years.
Specific topics include equations for calculating the state of opacity, developments in a double ablation front scheme for iron spectral opacity measurements in solar conditions, opacity enhancement due to diffusion-induced element accumulation inside B-type stars
, Monte Carlo simulations of biophysical factors for the viability of life in exoplanetary atmospheres, and the Belgian Repository of fundamental Atomic data and Stellar Spectra: an insight into systematic line selection.
Approximately 20% of all B-type stars
(which make up about 20% of all naked-eye stars) exhibit emission lines of hydrogen and sometimes helium and iron, which vary on timescales of hours to decades.
The meeting focused on active OB-stars as laboratories for the study of physical processes leading to stellar activity and the ejection of circumstellar material, particularly the orbiting disk that is central to rapidly rotating B-type stars
with prominent emission lines of hydrogen in their spectrums (Be stars).
The 47 papers also investigate dust formation around main sequence B-emission stars with large infrared excess, the centrifugal magneto-spheres of magnetic B-type stars
, the density structure of 48 LibraeAEs circumstellar disk, and the origin of hard X-rays from ?
These are hot B-type stars
with at least one emission line (usually one of the hydrogen Balmer lines).
Accordingly, any short-lived, massive O-and B-type stars
that the cluster might once have harbored have already exploded as supernovae or are nearing that stage.
But astronomers increasingly recognize how ionizing radiation from massive and luminous O- and B-type stars
can kick-start the starbirth process in adjacent clouds of gas and dust.