ASTRO: DDO 005 Another you've probably never heard of

DDO 005/PGC 2689 is a strange galaxy near the right edge of my image. A
note at NED shows lots of confusion about this galaxy in the MCG catalog
(it is MCG -02-03-009). It reads: "Interacting? Perturbed SB? -- On
the arm is a nucleus or a star, and also a compact E or star [16 mag] is
found in it." The 16th magnitude object appears to be a star in my
image judging by its PSF (Point Spread Function). The 18th magnitude
object to the upper right however is not a star. To me it is just a
knot in a very disturbed looking galaxy. They are very common in such
galaxies. I'd have expected it to be classed as an irregular galaxy but
NED say it is a barred spiral classing it as SAB(s)m but of the
Magellanic type (named for the Magellanic Clouds.) The DDO is the David
Dunlop Observatory Catalogue of Low Surface Brightness Galaxies.

The other main galaxy in this field is NGC 255 on the far right.
Tully-Fisher measurements of the distances to these galaxies say both
are about 65 million light-years away. Redshift measurements are in
close agreement. Thus, while widely separated in my image, their
projected separation is only about 500,000 light-years. So it is quite
possible they have interacted in the past. This could explain their
appearance. NGC 255 is listed as SAB(rs)bc by NED and the NGC Project.
It has a bright core region and widely spread very low surface
brightness outer arms I barely picked up through the gunk.

This pair is located less than a half degree north of NGC 246, the Skull
Nebula. So you've likely had it in your field of view when looking at
this rather famous planetary nebula at low power.

NED had redshift data on only two other galaxies in the image but little
else on them. They both are at about the same but much greater distance
being a bit over 700 million light years away. With only 4 galaxies I
almost didn't prepare an annotated image. It was so quick and easy I
did it anyway.

Unfortunately this image is taken under very poor conditions. I never
realized how poor until I went to process it or I'd have immediately
retaken it. I'll try again this year if the weather allows. It is near
my -15 degree limit so takes a very good night. So far it hasn't
happened this year. Sky conditions have been worse than last year I
had to throw out 2 of the luminance frames. To compensate I merged the
color data into the luminance including a blue frame not used in the
color data. Seeing was about 4" this night so detail is very lacking.

14" LX200R @ f/10, L=9x10', RGB=2x10', STL-11000XM, Paramount ME

Rick
--
Prefix is correct. Domain is arvig dot net

Rick,

the stranger looks a bit like a planetary nebula...

Stefan

"Rick Johnson" schrieb im Newsbeitrag
. com...

DDO 005/PGC 2689 is a strange galaxy near the right edge of my image. A
note at NED shows lots of confusion about this galaxy in the MCG catalog
(it is MCG -02-03-009). It reads: "Interacting? Perturbed SB? -- On
the arm is a nucleus or a star, and also a compact E or star [16 mag] is
found in it." The 16th magnitude object appears to be a star in my
image judging by its PSF (Point Spread Function). The 18th magnitude
object to the upper right however is not a star. To me it is just a
knot in a very disturbed looking galaxy. They are very common in such
galaxies. I'd have expected it to be classed as an irregular galaxy but
NED say it is a barred spiral classing it as SAB(s)m but of the
Magellanic type (named for the Magellanic Clouds.) The DDO is the David
Dunlop Observatory Catalogue of Low Surface Brightness Galaxies.

The other main galaxy in this field is NGC 255 on the far right.
Tully-Fisher measurements of the distances to these galaxies say both
are about 65 million light-years away. Redshift measurements are in
close agreement. Thus, while widely separated in my image, their
projected separation is only about 500,000 light-years. So it is quite
possible they have interacted in the past. This could explain their
appearance. NGC 255 is listed as SAB(rs)bc by NED and the NGC Project.
It has a bright core region and widely spread very low surface
brightness outer arms I barely picked up through the gunk.

This pair is located less than a half degree north of NGC 246, the Skull
Nebula. So you've likely had it in your field of view when looking at
this rather famous planetary nebula at low power.

NED had redshift data on only two other galaxies in the image but little
else on them. They both are at about the same but much greater distance
being a bit over 700 million light years away. With only 4 galaxies I
almost didn't prepare an annotated image. It was so quick and easy I
did it anyway.

Unfortunately this image is taken under very poor conditions. I never
realized how poor until I went to process it or I'd have immediately
retaken it. I'll try again this year if the weather allows. It is near
my -15 degree limit so takes a very good night. So far it hasn't
happened this year. Sky conditions have been worse than last year I
had to throw out 2 of the luminance frames. To compensate I merged the
color data into the luminance including a blue frame not used in the
color data. Seeing was about 4" this night so detail is very lacking.

14" LX200R @ f/10, L=9x10', RGB=2x10', STL-11000XM, Paramount ME

Rick
--
Prefix is correct. Domain is arvig dot net