Massive Stars in Open Cluster Pismis 24
18.12.2006

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.

Halloween and the Ghost Head Nebula
30.10.2007

Halloween's origin is ancient and astronomical. Since the fifth century BC, Halloween has been celebrated as a cross-quarter day, a day halfway between an equinox (equal day / equal night) and a solstice (minimum day / maximum night in the northern hemisphere). With our modern calendar, however, the real cross-quarter day will occur next week.

PanSTARRS: The Anti Tail Comet
29.06.2013

Once known as Earth's sunset comet, PanSTARRS (C/2011 L4) is up all night now, but only for northern hemisphere skygazers. Telescopes are required to track its progress as it fades and heads for the outer solar system.

Jupiter in 2015
23.10.2015

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.

Geminids of the South
16.12.2015

Earth's annual Geminid meteor shower did not disappoint, peaking before dawn on December 14 as our fair planet plowed through dust from active asteroid 3200 Phaethon. Captured in this southern hemisphere nightscape the meteors stream away from the shower's radiant in Gemini.

Moon over Makemake
30.12.2022

Makemake (sounds like MAH-kay MAH-kay), second brightest dwarf planet of the Kuiper belt, has a moon. Nicknamed MK2, Makemake's moon reflects sunlight with a charcoal-dark surface, about 1,300 times fainter than its parent body.

Active Galaxy NGC 1275
25.01.2023

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.

Pandora s Cluster of Galaxies
8.06.2023

This deep field mosaicked image presents a stunning view of galaxy cluster Abell 2744 from the James Webb Space Telescope's NIRCam. Also dubbed Pandora's Cluster, Abell 2744 itself appears to be a ponderous merger of three different massive galaxy clusters some 3.5 billion light-years away toward the constellation Sculptor.

Herbig Haro 24
27.05.2025

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: 2026 May 25 Б Thackerays Globules
24.05.2026

What are these strange space globs? Situated in rich star fields and glowing hydrogen gas, these opaque clouds of interstellar dust and gas are so large they might be able to form stars. Their...