Three Hearts (IC1805)

Here's an example of how versatile narrowband imaging can be. Below are three examples of the exact same data, presented in three different color mappings. The data was acquired with an Apogee U16M CCD camera attached to a Takahashi CCA-250 Astrograph. Each channel consists of four 15-minute exposures through Hydrogen Alpha, Sulphur II and Oxygen III filters.

Click on any of the small images to see a larger size.

The first image seen here is using the Hubble color palette. So named for the color mapping used in Hubble Space Telescope images. Here the RGB color channels are mapped to SII, Ha, and OIII respectively, giving these images their distinctive gold hue.












This next image is presented in the CFHT (Canada France Hawaii Telescope) palette. Here the RGB colors are mapped to Ha, OIII, SII, respectively. This gives a bit more of a "natural" color appearance, although all the images here are false color images.












I don't know that this final color mapping has a name, as such. Here, the RGB channels are mapped to Ha, SII and OIII, respectively. This is probably my least favorite as it imparts too much of an orange hue to the image for my tastes.

Narrowband imaging can be quite rewarding in more than one way. Not only can you create some colorfully beautiful images, but it extends the amount of time that we have to do imaging as well as from where we can image. Because the bandpass of these images is so much, well, narrower than normal RGB filters, they can easily cut through the light pollution for an observatory located in the middle of a big city or through the sky glow of the full moon.

Tags: apogee u16m, astrophotography, heart nebula, hubble palette, ic1805, narrowband imaging, takahashi cca-250 Posted Under Astronomy, Pretty Pictures, Photography, Astrophotography on 11.5.2011

NGC281 - A second try

We found that our club's TOA-130/U16M imaging set up had a problem with the imaging chip not being perpendicular with the camera's chip. This was causing stars to become defocused badly at the bottom of our images, but also seemed to be causing an overall loss of sharpness. We received a spacer that was installed between the off-axis guider and the camera which solved the problem and makes a world of difference. So, we are now going back to some of our previous targets to see if we can improve upon them. Below is a Before and After comparison.

Before

Original post can be found here.
Takahashi TOA-130
Apogee U16M @-12.5C
Astrodon Gen2 Narrowband Ha, OIII, SII
6X600 seconds per channel, 9 darks
Deep Sky Stacker, Post process in Photoshop CS5





After

Takahashi TOA-130
Apogee U16M @-12.5C
Astrodon Gen2 Narrowband Ha, OIII, SII
3X900 seconds per channel, Ha added as Luminance, 9 darks
Deep Sky Stacker, Post process in Photoshop CS5

Aside from having the new spacer, I've made some improvements to my Hubble Palette processing technique that I think has really made an improvement upon the image overall.

Tags: astrophotography, hubble palette, narrowband imaging, ngc281, pacman nebula Posted Under Astronomy, Pretty Pictures, Photography, Astrophotography on 10.15.2011

NGC884 & 869 - The Perseus Double Cluster

This is one of my favorite visual astronomical targets, the Perseus Double Cluster, which consists of NGC884 and 869. Easily visible to the naked eye from only a moderate dark site as a hazy spot just beneath Cassiopeia, these two open clusters are a site to behold in a wide telescopic field. Even a moderate pair of binoculars provides will afford an inspiring view.

Unfortunately, open clusters don't make overly interesting photographic targets. But, I was bored, didn't have a lot of time and the waxing gibbous moon was making anything other than narrowband imaging tough to do. The image here (click to enlarge) is a composite of RGB channels which consists of 20 one-minute exposures per channel using a Takahashi TOA-150 refractor and Apogee U16M CCD camera.

Tags: double cluster, ngc869, ngc884 Posted Under Astronomy, Pretty Pictures, Photography, Astrophotography on 09.8.2011

M13 and Friends

As always, click on the thumbnail for larger version. It really makes a difference in this case.

The star of the show here is Messier 13, one of the showpiece Globular Clusters in the northern hemisphere. One of about 160 such clusters that are arranged in a halo around the Milky Way, M13 is about 25,100 light years away and contains in the neighborhood of 300,000 stars.

Once done being dazzled by M13's pile of diamonds, the eye gets drawn to a couple of smaller, yet interesting objects. Immediately noticeable is the 12th magnitude galaxy NGC6207. It's an interesting contract in that it is another galaxy like, but smaller, than the Milky Way but around 45 million light years from us, about 100 times further than M13!

To add even more perspective, about half-way between NGC6207 and M13, another tiny galaxy can be seen, IC4617. Shining at about 15th magnitude, this galaxy is about 500 million light years from us, about another 100 fold distance increase from NGC6207.

Images like this that give this kind of comparison always make my head spin. Three objects within the same small slice of sky at radically different distances really put the universe in perspective.

Ok, so, about the image.
Date: Sept. 4, 2011
Telescope: TMB130SS
Camera: SBIG ST8300M @-5C
Mount: Losmandy G11
Filters: Baader LRGB
Luminance: 20 X 180 seconds
RGB: 10 X 180 seconds, bin 2X2
Stacked in DSS, post-processed in Photoshop CS5

Bonus! Here's a comparison image from last year. This one was taken with my AT106LE before I traded up to the TMB130, and with my Canon XSi dSLR instead of the ST8300 CCD camera. I believe it was also taken using an Astronomik clip-in light pollution filter, which would account for the slight blue cast that the image has.

I think I've made improvements over the past year.

Tags: astronomy, astrophotography, globular cluster, ic4617, lrgb, m13, messier 13, ngc6207, st8300m, tmb130ss Posted Under Astronomy, Pretty Pictures, Photography, Astrophotography on 09.6.2011

SH101 - With a nod to Tiny Tim

It's been a (finally) productive imaging week. We've had several nights that were at least partially clear and one that was clear, albeit hazily, from dusk till dawn. AND that night actually fell on a night when I didn't have to work the next day, so I was finally able get my own equipment under the stars. I've had this new set-up since June and I think this was the third time I've had it out, so far.


This session's target was the Tulip Nebula, also known as Sharpless 101. The Sharpless Catalog was compiled by Stewart Sharpless between 1953 and 1959 from the Palomar Sky Survey. It catalogs areas of HII nebulosity in the Milky Way, although it overlaps with other catalogs.

A false-color image, this is another example of the Hubble palette made of the combined light from Hydrogen Alpha, Oxygen III and Sulphur II wavelengths. Click the thumbnail for the full-sized image.

Statistics:
Data: September 2, 2011
Location: Sugar Grove Observatory
Telescope: TMB130SS
Camera: SBIG ST8300M @-5C
Filters: Baader Ha (6X600), OIII (12X600), SII (6X600)
Mount: Losmandy G11
Acquired with CCDSoft, stacked and calibrated with Deep Sky Stacker, post-processed with Photoshop CS5

Tags: astrpphotograph, losmandy g11, sh2-101, sharpless 101, tulip nebula.tmb130ss Posted Under Astronomy, Pretty Pictures, Photography, Astrophotography on 09.4.2011

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