Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2024 June 17

A starfield has a red nebula covering much of the frame
but in the centre, extending nearly vertically, is a blue
nebula that appears shaped, to some, like a squid.
Please see the explanation for more detailed information.

Ou4: The Giant Squid Nebula
Image Credit & Copyright: Alex Linde

Explanation: Squids on Earth aren't this big. This mysterious squid-like cosmic cloud spans nearly three full moons on planet Earth's sky. Discovered in 2011 by French astro-imager Nicolas Outters, the Squid Nebula's bipolar shape is distinguished here by the telltale blue emission from doubly ionized oxygen atoms. Though apparently surrounded by the reddish hydrogen emission region Sh2-129, the true distance and nature of the Squid Nebula have been difficult to determine. Still, one investigation suggests Ou4 really does lie within Sh2-129 some 2,300 light-years away. Consistent with that scenario, the cosmic squid would represent a spectacular outflow of material driven by a triple system of hot, massive stars, catalogued as HR8119, seen near the centre of the nebula. If so, this truly giant squid nebula would physically be over 50 light-years across.

Tomorrow's picture: thunder jets


< | Archive | Submissions | Index | Search | Calendar | RSS | Education | About APOD | Discuss | >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Amber Straughn Specific rights apply.
NASA Web Privacy, Accessibility, Notices;
A service of: ASD at NASA / GSFC,
NASA Science Activation
& Michigan Tech. U.