Ngc 3846a

NGC 3846A/UGC 06706 is a low_surface_brightness blue galaxy located in the bowl of the big dipper about 2 degrees northwest of Phecda at a red shift indicating a distance of about 74 million light-years. A single non redshift measurement says 82 million light-years. It is classified as SB(r)m: and I measure its longest dimension at 53,000 light-years including the huge plume to the northeast. Without the plumes it is about half that size. While it is listed as NGC 3846A, NGC 3846 is a full second field north of my frame. I'd not have expected it to be that distant. Also it is nearly 450,000 light-years distant so 6 times further away. They aren't related in any way.

Also not related is the apparent companion to the west MRK 1452. It is 310 million light-years distant and larger at 75,000 light-years by my measurement. While unrelated it forms a pair known as VV 320. It is a _starburst_ barred spiral classed as SBc. The core is surrounded by what looks to be a "Saturn-like" ring with the arms coming off the ends.

The galaxy or is it galaxies that really interest me are listed at NED only by position in the Sloan survey as SDSS J114339.35+550003.9 and SDSS J114339.95+550000.5. The former forms the head of a "comet" with the latter being a slight brightening in the southern edge of the tail just behind the former galaxy. I can't say if it i really a second galaxy or a faint star cloud in the tail. Is ASK 237743.0 involved? It is a Broad Line AGN which indicates its black hole is actively feeding. This could have been triggered with interaction with the other galaxy but with no redshift data for the "comet" there's no way to know. Certainly a dense galaxy like ASK 237743.0 could tear apart a loose spiral creating a mess without much harm to itself so I suspect its possible though if the brightening behind the "head" is a second galaxy they could have torn each other apart to make the comet without help from the other galaxy. I don't expect this to be studied for some time.

I had a heck of a time capturing this one. A bright star off the right hand side was sending all sorts of nasty ghosts into the frame. Whenever I put NGC 3846A anywhere near the center those ghosts ruined things. Normally a one minute move solves these but solve one and two cropped up. I felt like I was fighting Hydra. Finally this low position worked. That almost cost me the comet-like galaxy. I've had much brighter stars out of frame that caused far less problems. I don't know why this one was such a pain to deal with.

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

Rick

Rick,

quite confusing these numbers, at first I thought it was near NGC 3486, the
beautiful low surface brightness galaxy in Leo Minor.
Lots of small critters near the main object (which only narrowly escapes the
"small critter" category itself).

Stefan


"WA0CKY" schrieb im Newsbeitrag ...


NGC 3846A/UGC 06706 is a low_surface_brightness blue galaxy located in
the bowl of the big dipper about 2 degrees northwest of Phecda at a red
shift indicating a distance of about 74 million light-years. A single
non redshift measurement says 82 million light-years. It is classified
as SB(r)m: and I measure its longest dimension at 53,000 light-years
including the huge plume to the northeast. Without the plumes it is
about half that size. While it is listed as NGC 3846A, NGC 3846 is a
full second field north of my frame. I'd not have expected it to be
that distant. Also it is nearly 450,000 light-years distant so 6 times
further away. They aren't related in any way.

Also not related is the apparent companion to the west MRK 1452. It is
310 million light-years distant and larger at 75,000 light-years by my
measurement. While unrelated it forms a pair known as VV 320. It is a
_starburst_ barred spiral classed as SBc. The core is surrounded by
what looks to be a "Saturn-like" ring with the arms coming off the ends.


The galaxy or is it galaxies that really interest me are listed at NED
only by position in the Sloan survey as SDSS J114339.35+550003.9 and
SDSS J114339.95+550000.5. The former forms the head of a "comet" with
the latter being a slight brightening in the southern edge of the tail
just behind the former galaxy. I can't say if it i really a second
galaxy or a faint star cloud in the tail. Is ASK 237743.0 involved? It
is a Broad Line AGN which indicates its black hole is actively feeding.
This could have been triggered with interaction with the other galaxy
but with no redshift data for the "comet" there's no way to know.
Certainly a dense galaxy like ASK 237743.0 could tear apart a loose
spiral creating a mess without much harm to itself so I suspect its
possible though if the brightening behind the "head" is a second galaxy
they could have torn each other apart to make the comet without help
from the other galaxy. I don't expect this to be studied for some time.

I had a heck of a time capturing this one. A bright star off the right
hand side was sending all sorts of nasty ghosts into the frame.
Whenever I put NGC 3846A anywhere near the center those ghosts ruined
things. Normally a one minute move solves these but solve one and two
cropped up. I felt like I was fighting Hydra. Finally this low
position worked. That almost cost me the comet-like galaxy. I've had
much brighter stars out of frame that caused far less problems. I don't
know why this one was such a pain to deal with.

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

Rick


--
WA0CKY