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What are white dwarf stars? How do they form?
A white dwarf is the incredibly dense core of a dead star, left behind when the star exhausted its fuel. Our sun will become a white dwarf one day.
April 25, 2023
Hybrid solar eclipse: An annular-total on April 19-20
A hybrid solar eclipse will cross Australia, Timor-Leste and Indonesia on April 20, 2023. Surrounding areas will see a partial eclipse. Find maps and more here.
April 19, 2023
What is a neutron star? How do they form?
A neutron star is born from a supernova explosion. They contain a couple of times the mass of our sun, squeezed into a sphere the size of a city on Earth.
March 28, 2023
The attitude of the Swan and the Northern Cross
Guy Ottewell answers the question: Since the Northern Cross is vertical as it sets in the west, why is it not also vertical as it rises in the east?
March 17, 2023
Green comet passes Aldebaran on February 14 and 15
The green comet - Comet 2022 E3 (ZTF) - will pass near the bright star Aldebaran on February 14 and 15. Find maps and guidance on how to see the pair.
February 10, 2023
Comets and asteroids: What’s the difference?
Comets and asteroids both orbit our sun, but usually reside in different parts of our solar system. And except for a few, they're different materials.
January 31, 2023
Asteroid close encounter January 26: How to watch online
Asteroid close encounter today! Near-Earth asteroid (2023 BU) will pass safely 2,174 miles (3,500 km) away from Earth. Details here on how to watch online.
January 26, 2023
The 5 petals of Venus and its 8-year cycle
Learn about the 8-year cycle of Venus in our sky and the petals of Venus, a rhythmic motion of Venus when viewed from an Earth-centered perspective.
January 22, 2023
The green comet: Comet 2022 E3 ZTF
Learn about the trajectory of the green comet - Comet 2022 E3 ZTF - by the renowned astronomer Guy Ottewell. The comet will be closest to Earth on February 2.
January 17, 2023
What is a variable star?
What is a variable star? It's a star that brightens and dim in a cycle that might last hours, or weeks, or months, or longer. Astronomers know millions!
January 15, 2023
