Massive Stars in Open Cluster Pismis 24
19.12.2006

How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun, making it a record holder.

M2 9: Wings of a Butterfly Nebula
15.09.2013

Are stars better appreciated for their art after they die? Actually, stars usually create their most artistic displays as they die. In the case of low-mass stars like our Sun and M2-9 pictured above, the stars transform themselves from normal stars to white dwarfs by casting off their outer gaseous envelopes.

Jupiter in 2015
24.10.2015

Two remarkable global maps of Jupiter's banded cloud tops can be compared by just sliding your cursor over this sharp projection (or follow this link) of image data from the Hubble Space Telescope.

Active Galaxy NGC 1275
26.01.2023

Active galaxy NGC 1275 is the central, dominant member of the large and relatively nearby Perseus Cluster of Galaxies. Wild-looking at visible wavelengths, the active galaxy is also a prodigious source of x-rays and radio emission.

APOD: 2025 January 26 Б The Many Tails of Comet G3 ATLAS
26.01.2025

Why does this comet have so many tails? C/2024 G3 (ATLAS) has developed several long and intricate tails visible from Earth's southern hemisphere over the past two weeks. Many observers reported seeing the impressive comet without any optical aid above the western horizon just after sunset.

Herbig Haro 24
28.05.2025

This might look like a double-bladed lightsaber, but these two cosmic jets actually beam outward from a newborn star in a galaxy near you. Constructed from Hubble Space Telescope image data, the stunning scene...

APOD: 2025 December 17 Б W5: The Soul Nebula
17.12.2025

Stars are forming in the Soul of the Queen of Aethopia. More specifically, a large star forming region called the Soul Nebula can be found in the direction of the constellation Cassiopeia, whom Greek mythology credits as the vain wife of a King who long ago ruled lands surrounding the upper Nile river.

The Center of Centaurus A
1.10.2000

A fantastic jumble of young blue star clusters, gigantic glowing gas clouds, and imposing dark dust lanes surrounds the central region of the active galaxy Centaurus A. This mosaic of Hubble Space Telescope images taken in blue, green, and red light has been processed to present a natural color picture of this cosmic maelstrom.

Comet LINEAR Disperses
8.08.2000

What's happened to the nucleus of Comet LINEAR? The brightest comet this year has unexpectedly broken up into many smaller pieces. The break-up occurred on or about July 25 and was noted by many astronomers around the world with particularly pioneering work by Mark Kidger (IAC).

Solar System Portrait
14.02.2002

On another Valentine's Day (February 14, 1990), cruising four billion miles from the Sun, the Voyager 1 spacecraft looked back to make this first ever family portrait of our Solar System. The complete portrait is a 60 frame mosaic made from a vantage point 32 degrees above the ecliptic plane.