RCW 155

Also called

Sh 2-40, LBN 49

Coordinates: (12.72°, 0.35°)

[ Catalog | Explorer | SIMBAD ]

Sh 2-40 appears as several bright knots of nebulosity extending above the much larger nebula Sh 2-41.

Avedisova suggests that Sh 2-40 is ionised by the B-class star LSS 4756.

The RCW catalog lists the bit of Sh 2-40 that is furthest from the galactic plane as RCW 155a and the brighter bits closer to the galactic plane as RCW 155b.


Sh 2-40 lies in the same direction as the powerful radio source W 33, but the distance estimate for W 33 is about 4000 pc. So there may be two objects here in the same field of view, one visible only at radio frequencies. (On the other hand, the far range of the Avedisova distance estimate is just barely compatible with W 33.)

Avedisova associates Sh 2-40 with the young stellar object IRAS 18079-1756.

The massive protostellar object IRAS 18089-1732 is in the same area of sky but is located at a distance of 3600 pc.[1]

Notes

 1. ^ Beuther, H., Hunter, T. R., Zhang, Q., et al. (2004). "Submillimeter Array Outflow/Disk Studies in the Massive Star-forming Region IRAS 18089-1732", The Astrophysical Journal, Vol. 616, L23-L26. [2004ApJ...616L..23B]

Distance estimates

2400 pc [2003A&A...397..133R]
3300 pc [1975A&A....45..405V]
3200 pc +/- 500 [1989BAICz..40...42A]

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RCW 155


Most of the sources used to create these nebula descriptions are listed in the notes section for each description. In some cases, for example the Avedisova, Humphreys and Reed catalogs, the source is used extensively and is not listed in the individual nebula descriptions. See this catalog overview for more information on the catalogs and the general sources used to create these descriptions and this introduction to HII regions on the general history of this area of astronomy.

This image was created using the POSS-II/UKSTU data of the Digitized Sky Survey and SuperCOSMOS using the process described here.

According to my correspondence with the Royal Observatory Edinburgh and the Space Telescope Science Institute, I am allowed to use the POSS-II/UKSTU data to create and display images for non-commercial purposes so long as I include this fine print for the SuperCOSMOS data:

Use of these images is courtesy of the UK Schmidt Telescope (copyright in which is owned by the Particle Physics and Astronomy Research Council of the UK and the Anglo-Australian Telescope Board) and the Southern Sky Survey as created by the SuperCOSMOS measuring machine and are reproduced here with permission from the Royal Observatory Edinburgh.

and this acknowledgement taken from the DSS site:

The Digitized Sky Surveys were produced at the Space Telescope Science Institute under U.S. Government grant NAG W-2166. The images of these surveys are based on photographic data obtained using the Oschin Schmidt Telescope on Palomar Mountain and the UK Schmidt Telescope. The plates were processed into the present compressed digital form with the permission of these institutions.

The Second Palomar Observatory Sky Survey (POSS-II) was made by the California Institute of Technology with funds from the National Science Foundation, the National Geographic Society, the Sloan Foundation, the Samuel Oschin Foundation, and the Eastman Kodak Corporation.

The UK Schmidt Telescope was operated by the Royal Observatory Edinburgh, with funding from the UK Science and Engineering Research Council (later the UK Particle Physics and Astronomy Research Council), until 1988 June, and thereafter by the Anglo-Australian Observatory. The blue plates of the southern Sky Atlas and its Equatorial Extension (together known as the SERC-J), as well as the Equatorial Red (ER), and the Second Epoch [red] Survey (SES) were all taken with the UK Schmidt.

The "Second Epoch Survey" of the southern sky was made by the Anglo-Australian Observatory (AAO) with the UK Schmidt Telescope. Plates from this survey have been digitized and compressed by the ST ScI. The digitized images are copyright ? 1993-5 by the Anglo-Australian Observatory Board, and are distributed herein by agreement.

The "Equatorial Red Atlas" of the southern sky was made with the UK Schmidt Telescope. Plates from this survey have been digitized and compressed by the ST ScI. The digitized images are copyright ? 1992-5, jointly by the UK SERC/PPARC (Particle Physics and Astronomy Research Council, formerly Science and Engineering Research Council) and the Anglo-Australian Telescope Board, and are distributed herein by agreement.

The compressed files of the "Palomar Observatory - Space Telescope Science Institute Digital Sky Survey" of the northern sky, based on scans of the Second Palomar Sky Survey are copyright ? 1993-1995 by the California Institute of Technology and are distributed herein by agreement. The compressed files of the "Palomar Observatory - Space Telescope Science Institute Digital Sky Survey" of the northern sky, based on scans of the Second Palomar Sky Survey are copyright ? 1993-1995 by the California Institute of Technology and are distributed herein by agreement.