SH2-147

The region of SH2-147, SH2-148, SH2-149, SH2-152 and SH2-153 form the 2 cores of the 105 thousand solar mass molecular cloud [UUT2000] Cloud A according to galaxymap.org. Though their image of SH2-147 is the wrong nebula. I'd imaged SH2-152 back in 2008 I'd not realized I could have included all these other objects as well. So I reimaged the area in September 2010 then somehow forgot about it. In yet another sweep of the hard drive, it showed up. So this is yet another long-lost image I didn't realize I had. I found a second lost object but it had too poor red and green data so I know why it never got processed but it also never got back on the to-do list either so it sat in limbo as well.

SH2-147, 8 and 9 form one core in the lower right of my image with SH2-149 the bright member. SH2-147 is very faint and mostly off the frame. It would need much more time with a narrow band filter for proper exposure. While SH2-148 is on the frame it is hard to see as well. The annotated image points to its coordinate location. How it's seen as a separate object I don't know. There are other obvious pieces around SH2-149 that I can't find in SIMBAD at all. Some are HII regions other reflection nebulae of some sort (IFN in some cases?). Well above SH2-149 is the variable star DI Cephi. It sits in a dark hole in this large faint nebulosity. Apparently, the dark hole is just a gap in whatever is being illuminated as no dark nebula or bright nebula is listed for this area that I could find.

SH2-152 and SH2-153 seem oddly named since these are normally in Right Ascension order. Like SH2-148, I have trouble seeing SH2-153 as a separate object from the much brighter SH2-152. While the illuminating stars for SH2-149 appears to be a small star cluster [BDS2003] 35 the star cluster [BDS2003] 36 illuminates SH2-152 according to galaxymap. Within the nebula is a young stellar object likely formed from the nebula. Another is nearby to the southeast. See the annotated image. To the southeast of SH2-153 is the large rather faint region apparently caused to glow by CG) 649 a 09.5V star. It is IRAS 22571+5828 as best as I can determine. That object is listed in SIMBAD as a composite object, whatever that means. I have no idea if this object is related to the Sharpless objects or not. Other small reflection nebulae are seen around SH2-152 but I don't find them in SIMBAD.

While the annotated image points to the position that SIMBAD and others use for SH2-153 I can't help but wonder if the large object to the southwest might not be the "real" SH2-153. It seems too obvious to have been overlooked by Sharpless. By the same token SH2-248 is virtually invisible but the small blob to the northeast of SH2-149 is obvious. Could 149 be 148 and the anonymous object 149? I'm pretty ignorant on the Sharpless objects so I may be way off base here. Anyone have better knowledge here? I have seen some amateur images of SH2-152 and 3 that do consider the large faint cloud as SH2-153 but all of SH2-148 seem to point to the area I've noted in the annotated image.

I find little distance information. One paper says 1000 to 3000 parsecs.

My original 2008 image of the SH2-152 region was taken under better seeing but my color processing was poor or the data was poor. I don't know which. It is listed under SH2-152 and SH2-153.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for SH2-147

SH2-152

Sh2-152 is the bright nebula in the image. To its southeast is the larger but much fainter Sh2-153. The two are considered to be part of the same cloud with a mass of 105,000 suns. Some sources put it at about 15,300 light-years distant. Both parts are considered to be ionized by the unnamed O9 stars in Sh2-152.

14" LX200R @ f/10, L=6x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for SH2-152

SH2-156

Sh2-156 is also IC 1470. Galaxy Map is normally a good source for info on these but it seems confused. It gives a distance of precisely 4891 parsecs (15,300 light years) then says it is estimated to be 3500 to 4000 parsecs away (11,400 to 13000 light years). Then goes on to say it is part of the star cluster NGC 7510. Huh? The cluster is about 8 tenths of a degree northeast of the nebula and about 10,000 light years distant. Parts of Sharpless 2-157 (8000 lightyears) do extend into the field with NGC 7510 but certainly, Sh2-156 does not.

There are many other fuzz patches in the field. SIMBAD only identified the brighter ones. I've prepared an annotated image of these. Most carry very unfamiliar designations. The BF catalog is one of HII regions, GN is a reflection nebula. BDS denotes a star cluster. One small fuzz patch that is HII to the south and reflection to the north was centered on the position of an IR source found by IRAS. I don't know if the nebula is the optical counterpart to what IRAS was seeing or not. If so IRAS probably was looking at new stars buried in dust and gas that don't show visually. Some of the HII regions come through blue in my image. I'm guessing they have a reflection component as well as HII and my chip, being rather red insensitive, is seeing the reflection part better than the HII.

Due to clouds, I was only able to use half my green and blue data but all of the red was used. That should have favored the HII yet apparently didn't.

14" LX200R @ f/10, L=4x10' R=2x10'x3 GB=1x10'x3, STL=11000XM, Paramount ME

Related Designations for SH2-156

SH2-157

Sh2-157 is a rather bright but small emission nebula in a huge but very faint emission complex covering several square degrees of sky known as the Linds 11 group. It is located up near M52 and NGC 7510. In fact, part of the Linds 11 group reaches nearly to NGC 7510. Since it is far larger than my field I centered on the brightest portion sometimes known as Sh2-157b and LBN537. The nebula is estimated to be about 8,000 to 11,000 light years distant depending on which source you use. It is thought to be in the Perseus arm of our galaxy. It is located on the Cepheus-Cassiopeia border which runs through the western third of the image.

14" LX200R @ f/10, L=4x10'+Ha1x30' R=2x10'+Ha1x30'*80% G=2x10', B=2x10'+Ha1x30'*20%, STL-11000XM, Paramount ME

Related Designations for SH2-157

SH2-165

Sh2-165 AKA LBN 565 is a rather faint emission nebula Cassiopeia 1.75 degrees east of M52. It is likely part of the Cas OB5 supershell. I found three different distance measurements: 1.6±.5kpc, 1.9±.4kpc and simply 1.7kpc. In light-years that's 5,200±1,600; 6,200±1,300 and 5,500 light-years respectively. So say between 5000 and 6000 light years wouldn't be too far off. Distances to such objects is not easy to determine. It's surprising three different methods agreed so well. The one reference to its illuminating star says it is a B0.5V star but didn't give a position. I assume it is the bright one at the core but sometimes this isn't correct. While it is blue it doesn't seem as blue as I'd expect for a main sequence early B giant star.

I find very few amateur images of this one. The only one I found was Dan Crowson's image which I apparently missed when he posted it it taken on Sept 6, 2012. It gives a better feel for how faint this one is. http://www.flickr.com/photos/dcrowson/7951182598/ . Interestingly my image straddles his. Due to my poor skies and my system that normally only images within 2 hours of the meridian I needed several nights to get my 2.5 hours of data. My first frame was taken on August 26 and last September 13. It could have used more but after many tries, during that period I apparently decided to move on. While I did take some luminance data the Milky Way stars so dominated those frames I decided to only use the H alpha frames for the starfield as well as nebula as otherwise it would have been swamped by the stars. So the starfield was done solely from the RGB data and the nebula from a mix of RGB and Ha in which the red channel used 75% of the Ha data and the blue channel 20% to simulate H beta. This left the nebula rather magenta so 5% H alpha was added to the green channel to correct for that and probably simulate what little OIII this object emits.

14" LX200R @ f/10, Ha=3x30' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for SH2-165

SH2-168

Sh2-168 is a spherical cloud of ionized Hydrogen that is about 9.5 light-years across. It is also known as LBN568. It thought to be about 11600 light-years distant and is located in Cassiopeia to the northwest of Caph, the northwest star of the "W". The faint nebula to the southeast is Sh2-169. The two are likely part of the same cloud.

14" LX200R @ f/10, L=6x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for SH2-168

SH2-170

Sh-170 is an emission nebula in the northwestern corner of Cassiopeia not far south of Sh-171 on the Cepheus-Cassiopeia border. It is a round emission nebula with the open cluster Stock 18 at its center. Toward the left of the somewhat dark center is BD+63 2093p which is an 08V or 09V star. Galaxy Map says it has a mass 31 times that of the sun. There seems to be some disagreement. It is considered the illuminating star for the nebula. One distance measurement I found puts it 7500 light-years distant. The visible part of the cloud is thought to have a mass of about 900 suns give or take 10%.

14" LX200R @ f/10, L=4x10'+Ha3x30' R=2x10'+Ha3x30'*80% G=2x10' B=2x10'+Ha3x30'*20%, STL-11000XM, Paramount ME

Related Designations for SH2-170

SH2-171

Sh2-171 (see also NGC 7822) is a star-forming region in Cepheus. It is also known as Ced 214. It is far larger than my field so I've just picked a part of it including the star cluster Berkeley 59. APOD puts it at about 3000 light-years from us. Most images you see of this object are done using narrowband filters and the Hubble palette (SHO) in which SII (sulfur) is mapped to red, H alpha (Hydrogen) is mapped to green and OIII (oxygen) is assigned blue. I've used LRGB with some H alpha added since it is the prominent component of the nebula. I've tried to balance the colors to show what the eye would see if it were equally sensitive to all colors. In fact, the eye is most sensitive to green so the nebula would appear somewhat green to the eye if it were bright enough to register on our cones that see color. It is too faint to do this even in very large scopes so appears just as a faint gray smudge with the stars of Berkeley 59 dominating.

14" LX200R @ f/10, L=4x10+Ha3x30', R=2x10+Ha3x30*80% G=2x10' B=2x10'+Ha3x30'*20%, STL-11000XM, Paramount ME

Related Designations for SH2-171

SH2-175

SH2-175 aka LBN 596 is an emission nebula around LS I +64 26. Some sources say it is an O9.5 V star while others say it is a B1.5 V star. Not a big difference but still surprising. Less surprising is the uncertainty about the distance to this star and thus the nebula. I find estimates of 5100, 5550, and 6000 light-years by those saying it is a 09.5 V star. Russeil (yes, that is spelled correctly), who says it is really a B1.5 V star puts it at 3500 +/- 330 light-years. I assume the fact a B1.5 V star is a bit fainter than a 09.5 V star accounts for some if not most of the distance difference. All seem to agree that while it is seen in the area of the Cassiopeia OB1 complex it lies considerably closer to us and thus isn't part of the complex which is often said to be about 8200 light-years distant.

When I took this image I saw a nice blue reflection nebula just to its west. No image of the area showed it but since they all used H alpha for the luminance channel that didn't surprise me. But no enhancement of the POSS blue plates showed it either. I had to accept it was a reflection of some star doing a great impersonation of a reflection nebula and cloned it out. By the time I saw it the weather was constant clouds and snow so I've not been able to retake it but am quite certain it was bogus.

I'd wanted to take a lot of H alpha to add to the luminance and RGB data but clouds had other ideas. While I got one 30 minute frame before the clouds totally shut me down they greatly reduced the 30 minute shot to where it hardly helped but did create some nasty red halos around red stars. Still, since it helped the image a bit I included it in the mix.

14" LX200R @ f/10, L=4x10' HA=1x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for SH2-175

SH2-187

SH2-187 reminds me of an angry wolf spider about to bite. No legs, just big, wide open fangs seen face on. I really need to retake this one at a larger image scale, I used 3x3 binning probably to reduce exposure time as this is a very faint object. It is also known as LBN 630. The dark nebula around it is LDN 1317-18. Why it has both numbers I don't know. One distance estimate I found say it is about 4700 light-years distant and is on the outer edge of the Orion arm. The nebula is surrounded by a large cloud of neutral hydrogen with a mass of about 7600 suns. IR shows the nebula to hide a lot of newly formed stars. The nebula appears to have a strong reflection element to it, likely due to some of these stars.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for SH2-187