Results 311 to 320 of about 3,957,653 (321)
Some of the next articles are maybe not open access.
2002
The matter in the Universe (its barionic component) is concentrated mainly in stars. Inside galaxies, stars contain more than 90% of the matter, and in galactic clusters, due to the existence of intercluster gas, stars contain more than 70% of the matter. The presence of heavy elements (heavier than carbon) in the intercluster gas, with an abundance of
openaire +2 more sources
The matter in the Universe (its barionic component) is concentrated mainly in stars. Inside galaxies, stars contain more than 90% of the matter, and in galactic clusters, due to the existence of intercluster gas, stars contain more than 70% of the matter. The presence of heavy elements (heavier than carbon) in the intercluster gas, with an abundance of
openaire +2 more sources
2003
Most of the stars that we observe in the night sky have all got one thing in common — they are on the main sequence. There are, of course, exceptions: Betelgeuse has left the main sequence and has become a red giant star, the hydrogen burning at the centre of its core has stopped, and now helium is burning by fusion processes; while Sirius B has ...
openaire +2 more sources
Most of the stars that we observe in the night sky have all got one thing in common — they are on the main sequence. There are, of course, exceptions: Betelgeuse has left the main sequence and has become a red giant star, the hydrogen burning at the centre of its core has stopped, and now helium is burning by fusion processes; while Sirius B has ...
openaire +2 more sources
Stellar Evolution and Nucleosynthesis: Main Sequence and Post Main Sequence
This thesis explores post-MS nuclear reactions, including triple-alpha capture and the “holy grail,” focusing on reaction rate calculations. Additionally, we analyze stellar surveys (GAIA, SDSS, HIPPARCOS) to construct color-magnitude diagrams and track stellar evolution. By studying stellar clusters, we identify coeval stars and MS turnoff points.openaire +1 more source
Symposium - International Astronomical Union, 1978
About 3/4 of the sky were searched spectroscopically for stars whose ultraviolet spectra (3640–4100 Å) match that of the Sun, at 20 Å resolution. Down to the limit of the BSC, only two were found: HR 7504 and HR 2290. No G2 V star matches the Sun. Stars that do match have (B-V) = 0m.66. The search has a bearing on effective temperatures of G dwarfs and
openaire +2 more sources
About 3/4 of the sky were searched spectroscopically for stars whose ultraviolet spectra (3640–4100 Å) match that of the Sun, at 20 Å resolution. Down to the limit of the BSC, only two were found: HR 7504 and HR 2290. No G2 V star matches the Sun. Stars that do match have (B-V) = 0m.66. The search has a bearing on effective temperatures of G dwarfs and
openaire +2 more sources