Sh 2-205
Coordinates: (148.54°, -0.24°)
[ Catalog | Explorer | SIMBAD ]
Both Sharpless and Avedisova list the O9 class multiple star HD 24431 as the main ionising star for the large diffuse Sh 2-205, sometimes called the Peanut nebula. Avedisova also lists two cooler B-class ionising stars.
A recent series of papers divides the nebula into three distinct regions (although at similar distances), with the B-stars ionising a different region than HD 24431. They also suggest that CY Cam (HD 24094) may be an O8.5 or O9 star instead of the usually suggested much cooler B8 and may be the main ionising star of LBN 148.11-0.45 (LBN 696) in this direction.
A 2011 paper states that CY Cam is a B1 III giant.
Like Sh 2-202, this nebula lies at the edge of the Cam OB1 association.
This false-colour hydrogen-alpha image reveals that Sh 2-205 is the brightest region of an even larger nebula.
You can see an infrared image here and a false colour visual frequency image here.
A recent series of papers divides the nebula into three distinct regions (although at similar distances), with the B-stars ionising a different region than HD 24431. They also suggest that CY Cam (HD 24094) may be an O8.5 or O9 star instead of the usually suggested much cooler B8 and may be the main ionising star of LBN 148.11-0.45 (LBN 696) in this direction.
A 2011 paper states that CY Cam is a B1 III giant.
Like Sh 2-202, this nebula lies at the edge of the Cam OB1 association.
This false-colour hydrogen-alpha image reveals that Sh 2-205 is the brightest region of an even larger nebula.
You can see an infrared image here and a false colour visual frequency image here.
Sh 2-205 was the subject of two recent papers, which divide the nebula into three distinct regions although at similar distances, with the B-stars ionising a different region than HD 24431 and adds CY Cam (HD 24094) as a potential ionising star. [1], [2]
CY Cam is a B1 III giant. [3]
A 2001 paper lists the O8 star HD 24451 as the main ionising star for Sh 2-205 instead of HD 24431. This appears to be an error, however, as SIMBAD says that HD 24451 is a K-class star in quite a different direction. [4]
CY Cam is a B1 III giant. [3]
A 2001 paper lists the O8 star HD 24451 as the main ionising star for Sh 2-205 instead of HD 24431. This appears to be an error, however, as SIMBAD says that HD 24451 is a K-class star in quite a different direction. [4]
Notes
1. ^ Romero, G. A. & Cappa, C. E. (2008). "Sh2-205 - I. The surrounding interstellar medium", Monthly Notices of the Royal Astronomical Society, Vol. 387, 1080-1092. [2008MNRAS.387.1080R]
2. ^ Romero, G. A. & Cappa, C. E. (2009). "Sh2-205 - II. Quiescent star-formation activity", Monthly Notices of the Royal Astronomical Society, Vol. 395, 2095-2102. [2009MNRAS.395.2095R]
3. ^ Tetzlaff, N., Neuhäuser, R., & Hohle, M. M. (2011). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, Vol. 410, 190-200. [2011MNRAS.410..190T]
4. ^ Zdanavicius, J., Cernis, K., Zdanavicius, K., et al. (2001). "Photometric Classification of Stars and the Interstellar Extinction near the Camelopardalis and Perseus Border", Baltic Astronomy, Vol. 10, 349-373. [2001BaltA..10..349Z]
Distance estimates
900 pc [1982ApJS...49..183B]1060 pc +/- 100 [1984NInfo..56...59A]
1000 pc +/- 200 [2008MNRAS.387.1080R]
Links
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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.