Massive Shell Expelling Star G79 29 0 46
25.09.2017

Stars this volatile are quite rare. Captured in the midst of dust clouds and visible to the right and above center is massive G79.29+0.46, one of less than 100 luminous blue variable stars (LBVs) currently known in our Galaxy.

Star Size Comparison 2
12.06.2018

How big is our Sun compared to other stars? In dramatic and popular videos featured on YouTube, the relative sizes of planets, stars, and even the universe are shown from smallest to largest. The featured video begins with Earth's Moon and progresses through increasingly larger moons and planets in our Solar System.

Hydrogen, Helium, and the Stars of M10
12.03.1999

Stars like the Sun use hydrogen for fuel, "burning" hydrogen into helium at their cores through nuclear fusion. But what happens when that hydrogen runs out? For a while, hydrogen burns in a shell surrounding the stellar core and the star expands to become a red giant.

Henrietta Leavitt Calibrates the Stars
3.09.2000

Humanity's understanding of the relative brightness and variability of stars was revolutionized by the work of Henrietta Swan Leavitt (1868-1921). Working at Harvard College Observatory, Leavitt precisely calibrated the photographic magnitudes of 47 stars to which all other stars could be compared.

LP 944-20: A Failed Star Flares
13.07.2000

The tiny spot circled on the right actually represents a big astronomical discovery -- the first detected flare from a failed star. Failed stars, termed brown dwarfs in astronomers' parlance, are too low in mass to ignite nuclear hydrogen burning in their cores, yet

2MASS J17554042 6551277
19.03.2022

2MASS J17554042+6551277 doesn't exactly roll off the tongue but that's the name, a coordinate-based catalog designation, of the star centered in this sharp field of view. Fans of the distant universe should get used to its spiky appearance though.

The 25 Brightest Stars in the Night Sky
18.12.2022

Do you know the names of some of the brightest stars? It's likely that you do, even though some bright stars have names so old they date back to near the beginning of written language.

Why Stars Twinkle
25.07.2000

This is what a star really looks like from the surface of the Earth. To the best the human eye can see, stars are so far away they appear the same as would infinitesimal points of light.

Small Star
5.06.1997

A dim double star system cataloged as Gliese 623 lies 25 light-years from Earth, in the constellation of Hercules. The individual stars of this binary system were distinguished for the first time when the Hubble Space Telescope's Faint Object Camera recorded this image in June 1994.

Neutron Star Earth
16.06.1995

If the Earth could somehow be transformed to the ultra-high density of a neutron star , it might appear as it does in the above computer generated figure. Due to the very strong gravitational field, the neutron star distorts light from the background sky greatly. If you look closely, two