Wednesday, July 16, 2014

Sh 2-137

The list rolls on with another faint nebula: Sh 2-137 in Cepheus. This object its also known as LBN 498 and has a brightness value of 5

This images represents 3.5 hours of integration on a night with a bright waning gibbous moon.

Sh 2-137
The bright star at left is GSC 04271-2621 with magnitude 4.57.

Tuesday, July 15, 2014

No Luck With the State Fair; Weather Update

Just a quick update--my entry into the Fine Arts competition was not accepted. That means I get to keep my nicely framed picture, although I'll probably make it a gift to someone.

Unfortunately the judges don't give explanations for their decisions. I'm going to speculate that it was seen as lacking a sufficient element of artistic merit. If that's their reasoning, I can certainly understand it.

The long-term forecast for conditions during the Jeffers star party suggests that the very cool weather we've been experiencing will come to an end just before the party begins. Temperatures will climb into the low 90s with dew points in the low 70s. Typical steamy Jeffers weather, and if it persists into the following week and the Nebraska Star Party, there may be some big bad thunderstorms to deal with.

Saturday, July 12, 2014

Imaging Targets for This Summer's Star Parties

I'm probably going to four star parties this summer: The Jeffers Starry Nights (JSN), the Nebraska Star Party (NSP), the South Dakota Star Party (SDSP) and Iowa Star Party (ISP). I'm hoping to do quite a bit of imaging at these, taking advantage of the dark skies and slightly more southern locations. It's not much, but every degree of elevation helps!

I'd like to bump along my Bright Nebula list work, and take a couple of pretty pictures, too.  The dark locations let me image reflection nebulae that I can't get from my light-polluted back yard. Another constraint is that whatever scope I bring to Jeffers will also be the one I use at NSP. So what should I image?

(1) I'd like to go really deep on the Iris (NGC 7023). It's a reflection nebula on the list, and it's pretty. Near by are some barely luminous clouds. A wide field shot with my AT65 will take them all in. The Iris a better target during the JSN/NSP time period than in late August. This would be a multi-hour object, to say the least.

(2) I've always wanted a good image of the Helix nebula (NGC7293). This is better imaged around labor day, so it should be during either the SDSP or ISP. ISP has darker southern sky, so that's where it will be imaged. The C925 produces a nice image scale for it.

The Helix from 2009 JSN.
The above is my only Helix image, taken using my TV102, an unmodded Canon DSLR, 16 x 180s @ ISO 1600. Not at all adequate. A few hours (or longer) of LRGB could be much better.

(2a) Other objects I would like to go really deep on are the Ring--see a previous post about the outer shell-- and the Dumbbell. Those would be best in the C925.

(3) I have only one so-so image of the eagle nebula (M16) from a couple of years ago. Unfortunately it doesn't include the portion of the nebula that's considered LBN 68, a list item. So that should be reimaged from a dark site. This would probably look better in the C925 but the wide field of the AT65 would be adequate. Best during JSN/NSP.

(4) There are a good number of large list items in Scorpius and Sagittarius that would image well in the AT 72. These should be imaged at JSN/NSP. These include Sh 2-13, 2-16, NGC 6334, IC 4628, IC 4701 and LBN 52. An hour each should produce images that could satisfy list requirements.

So there you are:

  • JSN and NSP get the Iris and the large list items. This means that I can travel to them with the smaller, lighter AT65. One pretty picture (Iris) and a flock of list items.
  • SDSP and ISP get the Helix, Ring, Dumbbell, and whatever else comes along. For those it's the C925. Pretty pictures all, and perhaps list items left over from July.

Now it's all up to the weather!

Thursday, July 10, 2014

Another Obscure "Bright" Nebula: LBN 185, and IC 1470

The AL Bright Nebula list has quite a few not-very-bright nebulae on it. Here's one that's bright enough to image from a red zone + a nearly full moon: LBN 185 in Cygnus, a 5 on the LBN brightness scale.
LBN 185
I believe LBN 185 is the bright area near the center of the image. There's another bright area at the left edge of the image, but so far as I know that has no designation. This took 3.8 hours of H alpha imaging, and even at that the background is still rather rough. A couple of nights before I also got this image of IC 1470:

IC 1470
On the other hand, IC 1470 is bright, and small. This was taken with a C925 at a focal length of 1480mm, while the LBN 185 image is wide field with a 422mm AT65EDQ.

Monday, July 7, 2014

Going a Little Deeper with M 57

When the first really deep images of M 57 started showing up, I was amazed at the wealth of structure that surrounded the familiar oval that gave the Ring it's name. As it turns out, many planetary nebulae show this kind of layered structure. The explosive events that drive the star's outer atmosphere into space aren't just a one-time event; instead, they can happen repeatedly, producing a set of expanding nested shells. The outer shells are older, farther from the central star, subjected to less intense radiation, more diffuse, and have had more time to cool, all of which means they are less luminous at visible wavelengths.

M 57 is quite bright and easy to image. Even the central star, elusive visually thanks to the diminished contrast in the Ring's interior, is easily imaged. But what about those outer shells? Can they be imaged by folks with modest gear?

Last night I made my first try at finding out. While waiting for another object to climb out of the trees, I had some time to spend on M 57. I used a C 925 SCT with a 0.63X focal reducer, an SBIG ST-8300M CCD camera shooting through a Baader Ha narrowband filter, and accumulated 39 minutes of 3-minute light frames. That's not very much, compared to some projects where one have a total exposure time of over five hours. But it was all I had time for last night.

The result was surprising, at least to me:

My image is on the left; at right is a deep image from the U of Oregon for comparison.

In both images the Ring is wildly overexposed, but you can see the second ring clearly in my 39-minute shot. Also visible are a couple of the brighter knots in the next outward ring.

The image scale here isn't the greatest, and only 39 minutes through an Ha filter leaves a lot of noise, but I think it's going to be worth going back to this and shooting for hours. 

If you haven't tried going deep on M 57, you might give it a try. The result may surprise you, too.

Sunday, July 6, 2014


This is the first image of the year! Let's just say it's been a bad year. Amazingly everything worked smoothly, including me. This is yet another AL Bright nebular object, LBN 331.

A so-so picture, but I'll take it--LBN 331 is a brightness 4 object, so given my skies I don't expect much from 1.6 hours total exposure.

LBN 331
Details are here.

Tonight's supposed to be clear again (we'll see), so with luck I can bag another object, or go back to this one and shoot some RGB so that the stars have color.

Friday, July 4, 2014

Framed and Registered

The print of M31 I talked about last time has now been framed, and I've registered it for the Fine Arts competition at the State Fair.  Here's what it looks like framed:

This is a snap using an inexpensive digital camera, and I think it went blue-heavy, but you get the idea. The matte and frame are blacker than this shows. I chose anti-reflection glass, too, which lends a very slight blue tinge, much like it can do when viewed on a lens.

In a fit of optimism I decided to put a for-sale price on it. My cost, disregarding time and travel is $14 for the print and $261 for the framing, for a total of $275. The fair takes 20% of the sale price, so that becomes  $330. I set the price at $350, which means I'll have a "profit" of $20. 

Two things about that. It would be nice to have the costs taken care of, and it would be a great pleasure to know someone was willing to pay for one of my images. Seeing it hanging in the Fine Arts building with a "sold" sticker would be a blast. 

One thing at a time, though, and I won't find out what its status is until July 14-15. If it's accepted, I'll take all the mounting hardware off, and my wife will deliver it to the Judges (I'll be at the Nebraska Star Party).

This week I should really finish my Binocular mount project. The Jeffers Stargaze and NSP are going to arrive quicker than I know.