Messier 78

Messier 78
Reflection nebula
Image of Messier 78 captured using the Wide Field Imager camera on the MPG/ESO 2.2-metre telescope at the La Silla Observatory.
Observation data: J2000.0 epoch
Right ascension05h 46m 46.7s[1]
Declination+00° 00′ 50″[1]
Distance1,350 ly (415 pc)[2] ly
Apparent magnitude (V)8.3[3]
Apparent dimensions (V)8′ × 6′[3]
ConstellationOrion
Physical characteristics
Radius5 ly
Notable featuresPart of the Orion complex
DesignationsCed 55u, DG 80, IRAS 05442-0000, [KPS2012] MWSC 0664, NGC 2068[1]
See also: Lists of nebulae

Messier 78 or M78, also known as NGC 2068, is a reflection nebula in the constellation Orion. It was discovered by Pierre Méchain in 1780 and included by Charles Messier in his catalog of comet-like objects that same year.[4]

M78 is the brightest diffuse reflection nebula of a group of nebulae that includes NGC 2064, NGC 2067 and NGC 2071. This group belongs to the Orion B molecular cloud complex and is about 1,350 light-years distant from Earth.[2] M78 is easily found in small telescopes as a hazy patch and involves two stars of 10th and 11th magnitude. These two B-type stars, HD 38563 A and HD 38563 B, are responsible for making the cloud of dust in M78 visible by reflecting their light.[5]

The M78 cloud contains a cluster of stars that is visible in the infrared.[2] Due to gravity, the molecular gas in the nebula has fragmented into a hierarchy of clumps,[2] whose cores have masses ranging from 0.3 M☉ to 5 M☉.[6] About 45 variable stars of the T Tauri type,[7] young stars still in the process of formation, are members as well. Similarly, 17 Herbig–Haro objects are known in M78.[8]

On May 23, 2024, the European Space Agency released an initial set of images from their Euclid mission. This included an unprecedented image of the region including M78.[9] It showed hundreds of thousands of new objects including sub-stellar sized ones for the first time.

  1. ^ a b c Cite error: The named reference simbad was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Smith2013 was invoked but never defined (see the help page).
  3. ^ a b "Messier 78". SEDS Messier Catalog. Retrieved 30 April 2022.
  4. ^ Cite error: The named reference Frommert2018 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Strom1974 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Motte2001 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Herbig1963 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Zhao1999 was invoked but never defined (see the help page).
  9. ^ "Euclid's new image of star-forming region Messier 78". The European Space Agency. ESA/Euclid/Euclid Consortium/NASA. 23 May 2024. Retrieved 27 May 2024.