What is the origin of the letters used in star classification? Why didn't astronomers use ABCD? J. HaldimanChicago, Illinois ...

Our Sun formed with hundreds to thousands of sibling stars. These stars have drifted apart over billions of years. Scientists use stellar spectra and orbital data to identify potential siblings. The ...

Transmission spectroscopy during planetary transits is expected to be a major source of information on the atmospheres of small (approximately Earth-sized) exoplanets in the next two decades. This ...

Stark broadening, the widening of spectral lines due to the perturbing influence of electric fields from electron collisions, plays a pivotal role in the analysis of stellar atmospheres. This ...

Stellar spectral classification utilizes seven main classes (O, B, A, F, G, K, M), ordered by decreasing surface temperature, with each class further subdivided into numerical subclasses (0-9) ...

On July 21, Sky and Telescope contributing editor Tom Field will show how to capture stellar spectra using telescopes as small as 6-inch or with dslr cameras. The program will be accomplished using ...

At the dawn of the universe, there was only hydrogen and helium. These elements made up all the galaxies and all the stars. But stars fuse hydrogen and helium into heavier elements, and large stars ...