Astronomy Picture of the Day · April 18, 2004

Stellar Spectral Types: OBAFGKM

The Astronomy Picture of the Day for April 18, 2004 is “Stellar Spectral Types: OBAFGKM,” an image. The picture is copyrighted by its creator (Credit & Copyright: KPNO 0.9-m Telescope , AURA , NOAO , NSF). The original explanation runs about 119 words.

From the explanation

“Astronomers divide stars into different spectral types . First started in the 1800s, the spectral type was originally meant to classify the strength of hydrogen absorption lines .”

— APOD editors, April 18, 2004

Read the full explanation on science.nasa.gov

At a glance

Date: April 18, 2004
Type: Image
Credit: Credit & Copyright: KPNO 0.9-m Telescope , AURA , NOAO , NSF
Copyright: Copyrighted by the credited creator. Ask the copyright holder before reusing it.
Explanation length: About 119 words

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Source

Astronomy Picture of the Day, April 18, 2004 — science.nasa.gov/image-article/apod-2004-april-18-stellar-spectral-types-obafgkm

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.