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Ring Galaxy LEDA 087293 I think that's right



 
 
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  #1  
Old July 14th 16, 09:37 PM posted to alt.binaries.pictures.astro
Stefan Lilge
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Posts: 2,269
Default Ring Galaxy LEDA 087293 I think that's right

Rick,

Guide9 doesn't even find the LEDA number, so it seems to be an elusive
object. In spite of that it looks beautiful in your image, these ring
galaxies are faszinating.

Stefan


"WA0CKY" schrieb im Newsbeitrag ...


LEDA 087293 is a strange ring galaxy in southwest corner of Bootes. NED
classifies it as, well, nothing, which I found surprising. Another
catalog, the Low Surface Brightness Catalog lists it as a Ring galaxy
but then things get confusing. Their position has an error bar radius
of 37.5" but the position is about 45" from the galaxy's core. With
nothing else looking like a ring it appears they are talking about the
ring I imaged. Both LEDA and the LSBC have redshifts for it but again
they can't agree. LEDA says 1.72 billion light-years while LSBC says
only 520 million light-years, less than one third the distance. But
then there seems to be a second galaxy within the ring. A fainter one
is seen to the left of the central one. LEDA's position matches the
brighter central one. Could it be that they really meant the fainter
and possibly more distant one? The GALEX satellite records a UV source
half way between and slightly below the two "cores" but it's error bar
radius is 3" and thus can include both objects! It is closer to the
faint galaxy. So which it means can't be determined. If the LEDA
distance is used the ring is 250,000 light-years across. If the LSBC
distance is used then it is only 75,000 light-years across. Neither NED
nor SIMBAD show any object at the position of the second core unless it
is the GALEX object. Here I thought I was imaging a neat galaxy. I
didn't realize I was actually imaging a can of worms.

The LEDA distance of 1.72 billion light-years is echoed by many other
galaxies in the field as shown by the annotated image. NED shows
several small galaxy groups with this distance and one large galaxy
cluster GMBCG J208.39970+09.70305 centered to the easy at 1.69 billion
light-years and having 23 members. With no size given I can't tell if
it encompasses all galaxies at about the 1.7 billion light-year distance
but I assume it likely does.

The field contains two possible quasars besides some identified ones.
One is lists as a candidate quasar by NED so is labeled CQ while the
other is listed as an Ultraviolet Excess Source so is listed as UvES in
the annotated image.

Transparency was poor for this image. I tried over several nights but
much of the data was unusable. One luminance frame was taken a night
when an asteroid, (460453) 2014 SV218 was in the frame. It was listed
as 19.4 magnitude but appears a magnitude fainter showing how poor the
night was. With only a single 10 minute trail, some of which was lost
to clouds it hardly looks like an asteroid in the image. Look west of
LEDA 087293 to find it in the annotated image. I used the three best
color frames for color data due to very low transparency. Turned out
one RED one hurt more than it helped so only 2 red ones were used though
one happened to be when skies were rather good so that alone likely
would have been sufficient though I used two.

14" LX200R @ f/10, L=4x10' R=2x10' GB=3x10', STL-11000XM, Paramount ME

Rick


--
WA0CKY

  #2  
Old July 15th 16, 07:35 AM
WA0CKY WA0CKY is offline
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First recorded activity by SpaceBanter: Feb 2008
Posts: 689
Default

I see this site has yet again crapped out by losing a post. I'll have to repost it.

Quote:
Originally Posted by Stefan Lilge View Post
Rick,

Guide9 doesn't even find the LEDA number, so it seems to be an elusive
object. In spite of that it looks beautiful in your image, these ring
galaxies are faszinating.

Stefan


"WA0CKY" schrieb im Newsbeitrag ...


LEDA 087293 is a strange ring galaxy in southwest corner of Bootes. NED
classifies it as, well, nothing, which I found surprising. Another
catalog, the Low Surface Brightness Catalog lists it as a Ring galaxy
but then things get confusing. Their position has an error bar radius
of 37.5" but the position is about 45" from the galaxy's core. With
nothing else looking like a ring it appears they are talking about the
ring I imaged. Both LEDA and the LSBC have redshifts for it but again
they can't agree. LEDA says 1.72 billion light-years while LSBC says
only 520 million light-years, less than one third the distance. But
then there seems to be a second galaxy within the ring. A fainter one
is seen to the left of the central one. LEDA's position matches the
brighter central one. Could it be that they really meant the fainter
and possibly more distant one? The GALEX satellite records a UV source
half way between and slightly below the two "cores" but it's error bar
radius is 3" and thus can include both objects! It is closer to the
faint galaxy. So which it means can't be determined. If the LEDA
distance is used the ring is 250,000 light-years across. If the LSBC
distance is used then it is only 75,000 light-years across. Neither NED
nor SIMBAD show any object at the position of the second core unless it
is the GALEX object. Here I thought I was imaging a neat galaxy. I
didn't realize I was actually imaging a can of worms.

The LEDA distance of 1.72 billion light-years is echoed by many other
galaxies in the field as shown by the annotated image. NED shows
several small galaxy groups with this distance and one large galaxy
cluster GMBCG J208.39970+09.70305 centered to the easy at 1.69 billion
light-years and having 23 members. With no size given I can't tell if
it encompasses all galaxies at about the 1.7 billion light-year distance
but I assume it likely does.

The field contains two possible quasars besides some identified ones.
One is lists as a candidate quasar by NED so is labeled CQ while the
other is listed as an Ultraviolet Excess Source so is listed as UvES in
the annotated image.

Transparency was poor for this image. I tried over several nights but
much of the data was unusable. One luminance frame was taken a night
when an asteroid, (460453) 2014 SV218 was in the frame. It was listed
as 19.4 magnitude but appears a magnitude fainter showing how poor the
night was. With only a single 10 minute trail, some of which was lost
to clouds it hardly looks like an asteroid in the image. Look west of
LEDA 087293 to find it in the annotated image. I used the three best
color frames for color data due to very low transparency. Turned out
one RED one hurt more than it helped so only 2 red ones were used though
one happened to be when skies were rather good so that alone likely
would have been sufficient though I used two.

14" LX200R @ f/10, L=4x10' R=2x10' GB=3x10', STL-11000XM, Paramount ME

Rick


--
WA0CKY
 




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