January 30, 2012

More NGC 2903 (Jan. 26, 2012)

A cold front blew through and cleared off the sky.  But the cold front also made the air turbulent.  Seeing was therefore not the best on this night, and the resolution of this 5-hour integration of NGC 2903 suffered.  Still, it is deeper and more noise-free than the image I took last week.  I'm glad to have it.

Telescope: Orion 6" f/5 Imaging Newtonian with GSO Coma Corrector (effectively at f/5.5)
Camera and Exposure: SXVF-H9, 50x6'
Filter: IDAS-LPS2
Guiding: SX Lodestar, SX OAG
Mount: Takahashi NJP
Software: Nebulosity, Maxim DL, Photoshop CS3
Location: The Woodlands, TX

January 19, 2012

NGC 2903 (Jan. 18, 2012)

This is an old, familiar target for me.  There are a few hours in January-March when there is little else visible from my backyard that I can shoot in the eastern sky.  This year, I was planning on spending five hours on it to get a deeper image.  I was also trying out my re-furbed H9, back from England, and a new Astro-Tech coma corrector.  I transferred the FT focuser to the Orion 6" Imaging Newtonian, put the coma corrector on the filter wheel, and set up in the backyard.  I started at around 8:40 pm.  By 10:25, I was shooting and quickly realized that the distance between the coma corrector and chip was wrong, probably too far.  I went out, took the whole assembly apart, removed an extension tube, and put it all back together.  This image shows much better control, actually quite good.  I have some oddities left, which I cropped out.  I'm not sure whether they are from camera or corrector.
Anyway, I had everything focused and trained on NGC 2903 by midnight, and I was prepared to gather light on this distant galaxy for the next five hours.  After 40 minutes, I looked outside.  Clouds!  Ahhh.  How did that happen?  I checked the weather forecast.  It had changed while I was setting up, from clear to cloudy for the rest of the night.  Oh, bother.  I brought the whole assembly inside.
That is why this image is only 6x5'.  That's all I could get.   But, you know, I post what I get.  It's a blog, not an art gallery.  Transparency was about a 5 out of 10, so with reflected light of the burbs, there was a bit of sky glow.  But, hey, it's another galaxy, and these details are all available to those who can look up with the right equipment!  Distance estimates for NGC 2903 range from 20 to 38 million light years.

January 14, 2012

Quick Observing Session, SV80ED

Tonight was clear, but the moon was coming up soon.  I took the SV80ED out for a quick look.  Orion was high in the sky.  I used the 30mm at 18.6x for wide sweeps and to find things.  Then I ramped up to 112x with the 5mm Vixen Lanthanum for a close look.  If that was not close enough, I'd use the 2x barlow with the 5mm for 224x.  Seeing was not great.
Rigel, which I have always found easy in a good refractor, was cleanly split but with the companion only visible sometimes at 224x.  The brighter component danced about in the cooling air.  Temps probably began at around 48F and dropped 5 degrees while I was observing.
From Rigel, I went up to the Trapezium.  The F component blinked in and out, but E was buried in the seeing for me.  I could not spot it, either at 112x or 224x.  One could easily see the arms of M42 reaching out from the area.
Next up was Sigma Orionis, a multiple star system which is really a small cluster in the process of breaking up.  Nicely framed at 112x.
From there, I moved north and found M78 at 18.6x.  It's just a smudge of blue in my suburban sky.  I tried to get a closer look with the 5mm but could not see it.
Next over to Sirius, a great sight in the SVED80.  At 18.6x, I saw no false color at all.  It was just a beautiful white star in a lovely field.  From Sirius, I moved south to M41, which looked small and somewhat unimpressive in the wide field of the 30mm.  So I moved down to the next bright star in Canis Major and used it to find NGC 2362.  I always look for the Queen and Her Court, an open cluster of stars presided over by one particularly bright star complemented by several dimmer cluster members that shimmer and dance around her.  It reminds me of my bride and our beautiful children (ok, we don't have quite that many).  Of this cluster, the 30mm hardly revealed anything, and the 5mm blew up the picture too much.  Better get out the 10mm Vixen Lanthanum, I figured, which yielded 56x and framed the cluster perfectly.
The cold by this time was biting my fingers.  It was time to go in.  I snapped an image of the scope sitting on the Vixen Polaris mount.  The two go together perfectly.