Vela Molecular Ridge

Vela Molecular Ridge
NGC 2626, one of the brightest star-forming regions in the VMR.
Object typeGiant molecular cloud Edit this on Wikidata
Other designationsVMR
Observation data
(Epoch J2000)
ConstellationVela Edit this on Wikidata
08h 53m [1][2]
Declination−45° 00′[1][2]
Distance2300-6500[2] / 700-2000[2]
In visual light (V)
Size
8°
[edit on Wikidata]

Vela Molecular Ridge is a molecular cloud complex in the constellations Vela and Puppis. Radio 12CO observations of the region showed the ridge to be composed of several clouds, each with masses 100,000–1,000,000 M☉.[3] This cloud complex lies on the sky in the direction of the Gum Nebula (foreground) and the Carina–Sagittarius Spiral Arm (background).[3] The most important clouds in the region are identified by the letters A, B, C and D, and in fact belong to two different complexes: the clouds A, C and D are located at an average distance of about 700-1000 parsecs (2300-3300 light years) and are related to the OB association Vela R2, while cloud B is located at a greater distance, up to 2000 parsecs (6500 light years) away, and is physically connected to the extended Vela OB1 association.[4]

Part of the gas in the clouds is ionized by the ultraviolet radiation of some of the most massive stars associated with the complex, constituting H II regions of great extent, as Gum 14 (RCW 27) and Gum 20 (RCW 36). Stellar formation activity is confirmed by the discovery of several associations of T Tauri stars, particularly in the VMR D cloud,[5] as well as by the presence of several open clusters heavily obscured and deeply immersed in the gas observable at infrared wavelengths.[6]

The brightest and warmest stars of the Vela R2 association illuminate some filaments of gas that shine with a bluish light, typical of reflection nebulae. Among these is the well-known NGC 2626 nebulae which belongs to the VMR D cloud and hosts some stars presenting Hα emission and the famous Herbig-Haro object HH 132.[7]

  1. ^ a b 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 Vela was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference murphy91 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Murphy1991 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Pettersson1994 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Massi2006 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Ogura1990 was invoked but never defined (see the help page).