Messier 78
Reflection nebula in the constellation of Orion
Messier 78 (also known as M78 or NGC 2068) is a reflection nebula in the constellation Orion. It is the brightest diffuse reflection nebula in a group that includes NGC 2064, NGC 2067, and NGC 2071, all part of the Orion B molecular cloud complex. Located approximately 1,350 light-years from Earth, M78 is visible in small telescopes as a hazy patch illuminated by two B-type stars, HD 38563 A and HD 38563 B, of 10th and 11th magnitude. It is a popular target for amateur astronomers, who have given it the common name Casper the Friendly Ghost Nebula.
01Discovery
Discovered by Pierre Méchain in 1780, M78 was included in Charles Messier's catalog of comet-like objects that same year.
02Structure and composition
The nebula's dust cloud reflects light from its two central stars, making it visible. Infrared observations reveal an embedded star cluster and a hierarchy of gas clumps with core masses ranging from 0.3 M☉ to 5 M☉. M78 hosts:
- 45 T Tauri stars (young stellar objects still forming).
- 17 Herbig-Haro objects (jets emitted by nascent stars).
03Observations
On May 23, 2024, the European Space Agency released a high-resolution image of M78 from the Euclid mission, revealing hundreds of thousands of previously unseen objects, including substellar bodies.
Sources and credits
This article is adapted from the Wikipedia article “Messier 78”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Images, from Wikimedia Commons:
- Messier 78.jpg by ESO/Igor Chekalin, CC BY 4.0
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