Astronomy Picture of the Day ·

IC 4406: A Seemingly Square Nebula

The Astronomy Picture of the Day for April 16, 2000 is “IC 4406: A Seemingly Square Nebula,” an image. It is credited to Credit: H. Bond ( STScI ), R. Ciardullo ( PSU ), WFPC2 , HST , NASA. The original explanation runs about 105 words.

IC 4406: A Seemingly Square Nebula
Credit: H. Bond ( STScI ), R. Ciardullo ( PSU ), WFPC2 , HST , NASA Shown from science.nasa.gov. Not hosted by OpenOrbit.

From the explanation

“How can a round star make a square nebula? This conundrum came to light with the discovery of planetary nebulae like IC 4406.”

— APOD editors, April 16, 2000

Read the full explanation on science.nasa.gov

At a glance

Date
April 16, 2000
Type
Image
Credit
Credit: H. Bond ( STScI ), R. Ciardullo ( PSU ), WFPC2 , HST , NASA
Copyright
No copyright notice on the entry. Check the credited institution’s own usage rules before reusing it.
Explanation length
About 105 words

All of April 2000 → · 2000 by month → · Full archive since 1995 →

Topics in this entry

Nebulae

Topics are matched from words in the title and explanation.

On this day: April 16 in other years

On Amazon

Popular picks for space fans

As an Amazon Associate I earn from qualifying purchases.

Electronics Amazon Kindle Paperwhite Signature Edition 32GB Read astronomy and space-history books anywhere. View on Amazon → Electronics Bose QuietComfort Wireless Headphones Noise-cancelling headphones for documentaries and launch livestreams. View on Amazon →

Source

Copy taken Oct 28, 2026, 2:39 AM EDT. The image and explanation belong to their creators. OpenOrbit is not affiliated with or endorsed by NASA.