Thanks to my friend Milosz, my M27 has been gifted with some twelve and a half hours of pretty good old h-alpha signal. I have here merged that data to my Red channel, and composed the image above with PixInsight.
Posts Tagged ‘ED80’
My old M27 with some borrowed H-Alpha
Tuesday, September 13th, 2011M92
Tuesday, September 13th, 2011
M92
Here’s thirty-five five-minute shots at the M92 globular cluster in Hercules.
Messier 92 is about 26,700 light-years away and one of the brightest globular clusters of the northern hemisphere. It’s often overlooked, though, because of its proximity to the more prominent M13.
This is the first image flatted with my new light box. You can’t tell because this is a crop, but the box worked well.
A blue eye: the Dumbbell nebula M27
Thursday, September 1st, 2011
M27
Right after imaging the Gallardd C/2009 P1 comet, I managed seven subs of five minutes each on the Dumbbell nebula, aka M27, a planetary nebula in Vulpecula. To be fair, M27 needs no introduction, being one of the most prominent planetary nebulae we can enjoy.
As usual, my image lacks a lot of signal in the red channel, because regular DSLR are, by default, pretty much blind in the red part of the spectrum.
M27 has the notable characteristic of featuring a central star that is the largest known white dwarf.
Finally: Comet Garradd C/2009 P1, and a close-by M71
Wednesday, August 31st, 2011
Comet Garradd C/2009 P1
There it is. I have wanted to immortalize this comet since July, but it was too low for me. It finally arrived in Sagitta, but I missed the conjunction with M71 because it was overcast (no wonder), but luckily the two objects were still close enough the next day when it cleared up.
What you see above is the stack of fourteen frames, three minutes each. Of course the comet is moving and not the star, but I have aligned these images keeping the comet stationary.
In the next picture you can see the comet leaving a trail. It’s a larger field including the open cluster M71:
Garradd and M71
The Garradd C/2009 P1 comet was discovered, as the name implies, by Garradd in 2009 when its magnitude was 17.5.
These are its orbital elements:
Epoch 2011 Dec. 25.0 TT = JDT 2455920.5
T 2011 Dec. 23.67647 TT MPC
q 1.5505389 (2000.0) P Q
z -0.0006868 Peri. 90.74730 -0.16660676 -0.82691251
+/-0.0000006 Node 325.99770 -0.58719893 +0.52078281
e 1.0010648 Incl. 106.17743 +0.79211085 +0.21213431
From 1819 observations 2009 Aug. 13-2011 Aug. 10, mean residual 0".
This page contains a lot of information about the comet: http://cometography.com/lcomets/2009p1.html.
Messier 71, at the bottom of the picture, is a globular cluster in Sagitta. I’d like to quote an interesting parte from Wikipedia:
M71 was long thought (until the 1970s) to be a densely packed open cluster and was classified as such by leading astronomers in the field of star cluster research due to its lacking a dense central compression, and its stars having more “metals” than is usual for an ancient globular cluster; furthermore, it’s lacking the RR Lyrae “cluster” variable stars that are common in most globulars. However, modern photometric photometry has detected a short “horizontal branch” in the H-R diagram of M71, which is characteristic of a globular cluster. The shortness of the branch explains the lacking of the RR Lyrae variables and is due to the globular’s relatively young age of 9-10 billion years. The relative youth of this globular also explains the abundance of “metals” in its stars. Hence today, M71 is designated as a very loosely concentrated globular cluster, much like M68 in Hydra.
The globular cluster M13
Tuesday, August 30th, 2011
M13
I was waiting for the comet Garradd C/2009 P1 to rise behind my house, and the night hadn’t cast its darkness on my site yet. Well, by darkness I mean light pollution, but make what you want of it. Anyway, with the sky still blue I shot twenty images, three minutes each, to the most prominent globular cluster visible at my latitude.
The blob you see in the top left is nothing but three hundred thousands stars condensed in a mere 145 light years diameter.
Noticeably, the Arceibo message was directed to this cluster in 1974. I guess we won’t hear back for a while, given the estimated distance of twenty-five thousands light-years!
On the bottom-right of the image you can see the faint spiral galaxy NGC6207, in which a supernova was discovered in 2004. It’s forty-five million light-years away.
Fireworks Galaxy and an unremarkable open cluster
Saturday, August 27th, 2011
NGC6946 and NGC6939
NGC6946, aka the Fireworks Galaxy, owes its fancy name to being the galaxy in which the largest number of supernovae have been recorded. And that’s nine. Unfortunately my picture doesn’t show any, but the galaxy is framed with the nice and bright open cluster NGC6939.
The Fireworks Galaxy is quite near, at only ten million light-years, but lies behind clouds of dark nebulae in our Milky Way, since it’s pretty much on the galactic plane.
Curiously, I haven’t found a lot about NGC6939 online; I suppose it means that it’s a rather unremarkable open cluster.
This image is a crop because I had trouble with my flat frames (I accidentally shifted the focus knob) and therefore you can see defects and artifacts on the full frame. The night wasn’t particularly transparent, and 3.6 hours of exposure proved to be barely enough to show the galactic core.
And when there’s so little data to work with, stretching the histogram to the limit will show defects that are beyond the extreme care I can take in calibrating the frames, such as the non uniform sensitivity of the CMOS chip.
The west coast of North America
Saturday, August 20th, 2011
NGC7000
Great news! I got my first CCD camera: a Moravian Instruments G2-1600. It’s got a Kaf-1603ME sensor, so it’s a very sensitive NABG camera. I got narrow band filters too, so expect some images in the Hubble palette.
The image you see in this post was shot through a 12nm O-III filter.
It depicts what is usually put on the left in images of the North America nebula, NGC 7000.
An Iris nebula practically shot in daylight
Saturday, August 20th, 2011
Iris Nebula
Summer’s not over yet, but clear nights shall not be wasted. With the full moon and some degree of daylight in the atmosphere, just the core of this popular reflection nebula shows in the picture. It’s the stack of sixty 180-second sub-frames.
Back on the horse with an open cluster: NGC6871
Thursday, August 11th, 2011
NGC6871
Was the summer long? Yes it was! But here I am again, taking advantage of the few dark (-ish) hours we have at night. The Astronomical Twilight hasn’t reached my latitude yet (it will on August 23rd), but at the zenith it looks like it’s dark enough for some imaging.
The image you see above is a crop to 100%, so please click through for the full sized version. It depicts NGC6871, a young and bright star cluster in Cygnus. The cluster should be bathing in a see of red hydrogen-alpha clouds, but my unmodded Canon 450D is pretty much blind to that. And what you see is the stack of mere 33 minutes! It’s the only time I had before the clouds rolled in, but the result is not too shallow.
NGC2683: more elusive than I thought
Thursday, April 7th, 2011
NGC2683
Fifty-one times six minutes weren’t enough to capture a decent image of NGC2683, which might just be a target out of the scope of my equipment.
NGC 2683 is an unbarred spiral galaxy discovered by William Herschel on February 5, 1788. It was nicknamed the “UFO Galaxy” by the Astronaut Memorial Planetarium and Observatory. It is viewed nearly edge-on from Earth’s location in space and is located between 16 to 25 million light-years away. It is receding from Earth at 410 km/s (250 mi/s), and from the Galactic Center at 375 km/s (233 mi/s). The reddened light from the center of the galaxy appears yellowish due to the intervening gas and dust located within the outer arms of NGC 2683 (Wikipedia).
