NGC 6535 A Rarely Seen Globular Cluster

NGC 6535 is a rather obscure globular star cluster in Serpens Cauda. It is located about 22,200 light-years from earth but only 12,700 light-years from the center of the galaxy. Globular clusters orbit our galaxy in mostly highly elliptical galaxy spending most of the lives far from the center of the galaxy. But NGC 6535 is currently in the part of its orbit that carries it into the region of the galaxy's core. It is classed class XI on a scale in which I is most condensed and XII least concentrated. One as loose as NGC 6535 could be mistaken for a dense open cluster such as M 11. The cluster was discovered by John Hind on April 26, 1852 using a 7" refractor. He only found 4 NGC objects but one of them is NGC 1555 Hind's Variable Nebula.

NGC 6535 is an object I didn't have on my to-do list. On the night of October 14 I opened the the observatory while it was still a bit light. When the scope wakes up it goes to its "home" position which is an arbitrary point approximately two hours west of the meridian and nearly on the celestial equator. That night I took a preliminary image to see if all was working. There at the top of the image (south up) was a smudge in a 5 second exposure. Checking I saw it was this globular cluster. Looking it up I found virtually no images of it so decided to spend the 70 minutes on it even though it was well outside my image zone of good seeing. While seeing for this image is about 3.2" to 3.5" it came out surprisingly well. At least it is colorful.

Only a couple galaxies in the image had redshift values. CGCG 028-004 is the quite red elliptical galaxy to the west (right) of NGC 6535. It is about 330 million light-years distant. Near the right edge a bit below centerline is CGMW 3-1363 is listed as a spiral at 320 million light-years. None of the other faint fuzzies have distance data at NED at least.

Since it is seen against the Milky Way it is in a very rich star field which really blows up the size of a JPG image. The full size image, at 1" per pixel, is quite large and due to seeing not all that great but useful for those printing it out. Otherwise the reduced image at 1.5" per pixel is plenty sufficient. The cropped image is also at 1" per pixel.

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

Rick

Rick,

nice way to find a new object to image :-)
And a beautiful image of this cluster with very good star colours.

Stefan


"WA0CKY" schrieb im Newsbeitrag ...


NGC 6535 is a rather obscure globular star cluster in Serpens Cauda. It
is located about 22,200 light-years from earth but only 12,700
light-years from the center of the galaxy. Globular clusters orbit our
galaxy in mostly highly elliptical galaxy spending most of the lives far
from the center of the galaxy. But NGC 6535 is currently in the part of
its orbit that carries it into the region of the galaxy's core. It is
classed class XI on a scale in which I is most condensed and XII least
concentrated. One as loose as NGC 6535 could be mistaken for a dense
open cluster such as M 11. The cluster was discovered by John Hind on
April 26, 1852 using a 7" refractor. He only found 4 NGC objects but
one of them is NGC 1555 Hind's Variable Nebula.

NGC 6535 is an object I didn't have on my to-do list. On the night of
October 14 I opened the the observatory while it was still a bit light.
When the scope wakes up it goes to its "home" position which is an
arbitrary point approximately two hours west of the meridian and nearly
on the celestial equator. That night I took a preliminary image to see
if all was working. There at the top of the image (south up) was a
smudge in a 5 second exposure. Checking I saw it was this globular
cluster. Looking it up I found virtually no images of it so decided to
spend the 70 minutes on it even though it was well outside my image zone
of good seeing. While seeing for this image is about 3.2" to 3.5" it
came out surprisingly well. At least it is colorful.

Only a couple galaxies in the image had redshift values. CGCG 028-004
is the quite red elliptical galaxy to the west (right) of NGC 6535. It
is about 330 million light-years distant. Near the right edge a bit
below centerline is CGMW 3-1363 is listed as a spiral at 320 million
light-years. None of the other faint fuzzies have distance data at NED
at least.

Since it is seen against the Milky Way it is in a very rich star field
which really blows up the size of a JPG image. The full size image, at
1" per pixel, is quite large and due to seeing not all that great but
useful for those printing it out. Otherwise the reduced image at 1.5"
per pixel is plenty sufficient. The cropped image is also at 1" per
pixel.

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

Rick


--
WA0CKY