Astronomy Picture of the Day · March 31, 1999

PG 1115+080: A Gravitational Cloverleaf

The Astronomy Picture of the Day for March 31, 1999 is “PG 1115+080: A Gravitational Cloverleaf,” an image. It is credited to Credit: CISCO, Subaru 8.3-m Telescope, NAOJ. The original explanation runs about 152 words.

From the explanation

“All four blue images in the above photograph are the same object. The gravitational lens effect of the red, foreground, elliptical galaxy visible near image center creates a cloverleaf image of the single distant quasar .”

— APOD editors, March 31, 1999

Read the full explanation on science.nasa.gov

At a glance

Date: March 31, 1999
Type: Image
Credit: Credit: CISCO, Subaru 8.3-m Telescope, NAOJ
Copyright: No copyright notice on the entry. Check the credited institution’s own usage rules before reusing it.
Explanation length: About 152 words

All of March 1999 → · 1999 by month → · Full archive since 1995 →

Topics in this entry

Galaxies

Topics are matched from words in the title and explanation.

On this day: March 31 in other years

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Source

Astronomy Picture of the Day, March 31, 1999 — science.nasa.gov/image-article/apod-1999-march-31-pg-1115080-a-gravitational-cloverleaf

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.