Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
GSC 08225-985 (J111827.8-520821) RA 11:18:11.37 DEC -52:07:12.6 (J2000). Is it a DSO?
On some recent images I took of PN ESO 216-2, the field star GSC 08225-985 is recorded more like a faint fuzzy DSO rather than having a stellar profile like the other field stars. I was actually taking images of Planetary Nebula PN G288.7+08.1 (ESO 216-2) at R.A. 11h18m09.7s Dec. -52°10'02" (2000) in Centaurus, Magnitude: 15.50, Size: 36" when I noticed that the field star (GSC 08225-985) looked distinctly fuzzy and unlike the other nicely resolved field stars. It appears more like the faint PGC Galaxies I often see in my images.
The “fuzzy” field star is identified as:
SkyTools 4 Imaging Data
R.A. 11h18m27.9s Dec. -52°08'21" (2000)
Magnitude: 13.22
I have checked the Sesame Name Resolver on-line Query and it returned:
J111827.8-520821           11:18:27.8  -52:08:21
I also checked Aladin Lite and on that image the object appears in the Gaia EDR3 and 2MASS databases.
I have attached 5 files showing this “fuzzy” object, from the basic Raw File to Files with Labels and IDs from the SkyTools 4 Imaging Application.
I took a similar series of images on 6th June with a different camera (ZWO ASI 1600 MM Pro) and with the telescope tube rotated in a different position (approx. 45 degrees) and the same “fuzzy” object appears in that image too, so it is unlikely to be camera related or some reflection artefact?
The imaging system is:
Takahashi Mewlon 210 F11.5 (210mm aperture)
Takahashi x0.8 Reducer
F9.4 at 1932mm focal length
ZWO AIS 294 MM Pro Cooled Camera
106 x 30 sec exposures
10th June 2021
Brisbane, QLD, Australia.
Dennis Simmons

Attached Files Thumbnail(s)
Dennis, what does a DSS image show?

Phil S.

I downloaded the DSS red image from the ESO site & it also shows a fuzzy area around the star J111827.8-520821.

Phil S.
Hi Phil


Yes - I ran the "Get DSS Image at Cursor" in the Interactive Atlas of ST4 Imaging and it did show a non-stellar fuzzy region at that position. It does looks very similar to a typical faint fuzzy PGC Galaxy representation that I sometimes find in the background of my images and this piqued my interest.


Here are 1024x768 crops from the individual LRGB frames taken with the ASI 1600 MM Pro on 6th June 2021, and it looks like the "star" has been recorded as a diffuse or extended object in all 4 frames.





I managed to get out last night and grab a series of LRGB Frames 120:60:60:60 30 sec exposures each of PN G288.7+08.1 and the "mystery" object.

The "mystery" object "looks" like a faint fuzzy when you compare it to the nearby Galaxy LEDA 445548 at R.A. 11h18m59.9s Dec. -52°19'43" (2000) in Centaurus at Magnitude: 17.30 B shown in the wider field view.

Also, SkyTools 4 Imaging shows two objects at the location of PN G288.7+08.1; the PN itself and a Spiral Galaxy ESO 216-2 as follows.

ESO 216 2
aka PGC 34540
R.A. 11h18m09.6s Dec. -52°10'00" (2000) in Centaurus
Magnitude: 15.40 B
Size: 35" x 32"
Mean Surface Br. 22.3 Mag/arcsec²
Class: Spiral
Hubble Type: Sbc
Orientation: Face on
Status: known galaxy
It spans 176 x 162 pixels, for a scale rating of C .

The full res crop of the "mystery" object (Yellow circle) appears to show two bright concentrations within the extended fuzzy outline. The mystery continues...



Attached Files Thumbnail(s)

There's definitely an object there that looks like a faint galaxy. Good catch! I only checked the DSS red image, but your LRGB images suggest that it's visible in all 3 color filters. That also suggest a galaxy, doesn't it?

Phil S.
Thanks Phil, last night I had another go and fitted a Tak x1.6 Extender to the Mewlon 210 to give me F/18.4 at 3864 mm focal length and managed to rattle off 360 x 15 sec exposures (13th June) before wispy clouds moved in.

The attached image is a full res crop of the region of interest and I have included an inverted image as well. I am now thinking it could be a PN rather than a Galaxy?

The seeing was pretty bad so no further detail was really revealed. I think I would have to go to a dark sky site and take more frames to go any deeper with this.



Attached Files Thumbnail(s)

Is the fuzzy visible in your scope or is this an imaging target only? If visible & you have a filter that will enhance the appearance of a planetary, like an OIII filter I think that might help you distinguish between a planetary & a galaxy.

Pretty long shot, but it might help.

Phil S.
(2021-06-12, 10:57 PM)Dennis Wrote: Also, SkyTools 4 Imaging shows two objects at the location of PN G288.7+08.1; the PN itself and a Spiral Galaxy ESO 216-2 as follows.




I'm guessing that the object was misidentified (as either a PN or galaxy) in one of the source catalogs, so it shows up twice. But I am traveling and am not able to look into it min more detail. Cool stuff tho and nice images!
Clear skies,
Head Dude at Skyhound

Forum Jump:

Users browsing this thread: 1 Guest(s)