July 25, 2012

Iris Nebula, NGC 7023 (July 19 & 20, 2012)

This is the Iris Nebula.  The image was taken from the campus of the Three Rivers Foundation Comanche Springs Astronomy Campus near Crowell, TX.  I was planning on taking a trip to west Texas for four nights of imaging.  The weather would not allow it, though; it is monsoon season there, and little or no imaging with the portable kind of rig I use would have occurred, so that trip had to be postponed.  But I had a week available during a new moon.  An inquiry to the Three Rivers Foundation (3RF) proved helpful.  They offered to let me tent camp for free during open campus week, and asked only a small fee for use of the electricity.  I took my two sons.  Only the first night was great for imaging, but it was a great night.

In fact, that first night was fabulous.  The air was as still as I've ever seen it for imaging, and the night was very dark.  The Milky Way stretched from horizon to horizon.  Wow.  My boys had never seen it, but they won't forget it now.

The Iris Nebula is a reflection nebula, meaning that it reflects the light of the stars next to it.  The stars are blue-white, so the nebula shines in blue-white.  Reflection nebulae are much harder to see (or image) from the suburbs, so the Iris was a prime target from a dark sky site.  The bright star in the middle of the nebula provides much of the illumination.  It has just a number (SAO 19158), not a proper name, and is not a bright star to our eyes (just magnitude 6.8).

I obtained color data the second night.  The night was somewhat cloudy, and eventually I had to stop imaging.  The color data for this image is not the best, but it is just usable, and will suffice.

It would be hard to say enough good things about the 3RF campus.  There are scopes aplenty and accommodations for volunteers and visiting amateurs.  The folks in charge were welcoming and very helpful.  I met several serious amateurs there who were friendly and knowledgeable.  I hope to go back again soon.

Telescope: Orion 6" f/5 Imaging Newtonian and Astro-Tech Coma Corrector (eff. at f/5.5)
Camera and Exposure: SXVF-H9 (17x900'), SXVF-H9C (6x1200'), Alnitak Flat-man flats
Filter: Astronomik Lum
Guiding: SX Lodestar and SX OAG
Mount: Takahashi NJP
Software: Nebulosity, Maxim DL, Registar, Photoshop CS3
Location: 3RF's Comanche Springs Astronomy Campus, Crowell, TX

July 12, 2012

NGC 604 (from M33), HST

This data is from the Hubble Legacy Archives.  NGC 604 was discovered by William Herschel in 1784, but it lies in a nearby galaxy, M33, also called the Triangulum Galaxy.  NGC 604 is very bright, and is visible on nearly every image of M33, but the nebula, like the galaxy to which it belongs, lies roughly 2.8 million light years away.  Hubble's clear vision gives us such a close view.  This is not Hubble's most detailed data of this nebula, but it is a set I've not seen before.  This image combines blue, green, H-alpha, and deep red exposures.