JimH123 Loc: Morgan Hill, CA

With all the constant rain and clouds, thought I would reach back into last year's show and pull up the Owl Nebula.

I also decided to try out High Pass Sharpening. There is a very nice write up in the Feb 2016 issue of Popular Photography, page 36, on using the High Pass Filter, and I was familiar with that filter, but had never used it on stars. I must admit that the stars did become sharper points. I also pressed it harder on stars than I would normally do with other types of images.

This shot was using the 8" Orion Astrograph, 800mm at f3.9 with a coma corrector. The coma corrector is a must. The outer edge stars look terrible without it. There was no tracking and I limited the time to 30 sec shots, 10 of them. And then stacked in DSS. The Owl Nebula is actually quite faint and appears as just a smudge on individual images. But with 10 of them stacked, it started to take shape. I used a Sony A57 crop sensor camera at ISO 1600. The image has been cropped a bit.

This is definitely an object requiring more exposure time. The 10 images work out to only 3 minutes of exposure time. Far too little for this faint object.

Meanwhile, I want to get started with tracking, but I think it has been rainy or overcast every single day since buying the tracking camera. Maybe this is all it really took to end the California drought!

Owl Nebula

(Download)

SonnyE Loc: Communist California, USA

Who... who... looks good from here, too!
:lol:

Great, Jim!

I think we are in for a lot of poop weather.
You bought a guide scope and camera, Craig got a brand new Telescope, and I got my woe's repaired.

Yep, California is screwed, weather-wise.
We created the triangle of doom.

Please bare with me, but is that Dubhe and Phad with the spires?
I'm trying to learn to correlate... :oops:

JimH123 Loc: Morgan Hill, CA

Not sure. Would need to check against the star map.

SonnyE Loc: Communist California, USA

I did a quickie on Stellarium... :twisted:

(I'm so sneaky...)

But if one of them is Dubhe, I've learned from Alignments where it usually is, so could guesstimate where to look. ;)

Call me the rock that learns...

Albuqshutterbug Loc: Albuquerque NM

More like that rock that's turning to moss sitting in the rain..
Had to ..
:twisted: :twisted:

SonnyE Loc: Communist California, USA

Well, no. Not since I figured out how to operate remotely.
Shucks, I don't even get cold anymore.
If I feel a chill, I head indoors. (I usually do after alignment and focusing anyway.)
Then gather images from inside.
And make hot chocolate.
If doing a long exposure, I'll watch TV with the wife, and come back to the Telescope programs when convenient.
My reference to the rock was due to my slow learning. Some heads are harder than others. :lol:

JimH123 Loc: Morgan Hill, CA

I looked the stars up using StarryNight, and Dubhe is not one of them. Nor is Phad. They don't have any common names, or at least not common to me. But if you are into the HIP star series, maybe you would know them.

The Owl Nebula, M97, or NGC 3587, is listed as a magnitude of 9.9. But it is hard to compare a magnitude 9.9 of an extended object with a magnitude 9.9 star since the star is more focused in a single point. StarryNight lists it as 12th magnitude which probably better describes it.

It is 2030 light years away in the constellation Ursa Major, just below the bowl and closer to the outer end of the bowl. The tiny white dwarf star in the very center is the source of this nebula and is 14th magnitude (some web sites say it is 16th magnitude). It jettisoned its outer layer about 8000 years ago. The nebula is about 0.91 light years across. The article did not make clear if that was diameter or radius and another I read gave a size of twice the 0.91, so I suspect it is radius.

According to http://www.constellation-guide.com/owl-nebula-messier-97/, the Owl Nebula is one of the faintest Messier objects. It is quite large and has a relatively low surface brightness, but it can be seen in amateur telescopes in good conditions, with clear skies and no light pollution. It can even be spotted with larger binoculars. However, to see why the nebula was named the Owl, one needs a larger instrument, starting from an 8-inch telescope and moderately high power. The 14th magnitude central star (some say 16th magnitude) can be seen in 10-inch or larger telescopes.

M97 is considerably brighter visually than photographically because most of its light is emitted in one green spectral line.

The nebula can be found just below the bowl of the Big Dipper. It lies about 2.3 degrees to the east-southeast of the star Merak.

The name comes from the fact that in a large telescope, there are two darker regions that remind one of Owl eyes. They are just barely discernable in this image. There are 3 other fainter stars showing in the middle also. I can't find any reference to the other inner stars, but they are much fainter. I suspect they are located beyond M97 and are not part of the nebula.

If you can see the comet Catalina, it's tail is pointing straight at M97 (20 degrees from the nucleus).

The 1st attachment is a reminder of the stars of the Big Dipper.

The 2nd attachment is a repost of my image of the Owl Nebula with some stars identified.

In the 3rd attachment, the bright star towards the upper right is Merak. And the one to the left is Dubhe. Traveling from Merak, you will pass M108 before reaching M97.

The stars of the Big Dipper


Labeling stars near M97

(Download)

Locating M97

(Download)

CraigFair Loc: Santa Maria, CA.

Very cool shot Jim H. I've never scoped the Owl Nebula M97.
Craig

JimH123 Loc: Morgan Hill, CA

Its not hard to find if you have a clear shot at the Big Dipper. But I find that my ten 30 sec exposures just weren't enough time to really pull it in.

And M108 is right next door.

SonnyE Loc: Communist California, USA

Cool, Jim, Thank You!
When I entered the HIP number it shown the star in Stellarium in current relationship to the nebula.
When I zoomed in, I could make out the 'Owl Eyes' of the nebula.
Looks like another fun target to note.

HIP - it isn't slang for being cool, or a hippopotamus.

http://www.dibonsmith.com/hd_hip4.txt

I guess instead of bee-bopping around, I'll need to work through some of these catalogs. I have a good start on the Messier, 9 items so far.

CraigFair Loc: Santa Maria, CA.

Way to go Sonny are you doing them in Numerical order???
Craig

SonnyE Loc: Communist California, USA

Not yet. But I do have 1,2,8,13,20,27,31,42,57 so far.
I have a Messier Catalog in my phone. When I get one, I add it to my favorites. That makes a list of them.
I'm not even sure if I've kept up with it. I'm not one to keep score, I just love playing the field.

Since I discovered Stellarium, remote control, and hours long tracking, I tend to get lost in imaging.
Like tracking one item, then taking a bunch of various pictures.
Pretty soon I wake up, go gather the scope and laptop, cover things up, drain the dog, and go to bed.

But I've been threatening to put toothpicks in my eye lids and do an all niter when these damned clouds give us a clear night. :lol: :roll:
:lol: I tried last night and the clouds kept hiding the alignment stars. So I tried a Quick Alignment.
I guess that was the last straw. The clouds just covered the sky here, and tried to even hide the moon.
I said fine, and packed it in.

Today we have a 40% chance here. So I went and brought in the mount. As I removed the barrel and the canvas I noticed condensation... I no like that. It was light, but...
I'm not apt to let it sit out in this weather, covered, anymore.
RH (Relative Humidity) is 80%. Kinda steamy for a desert rat like me.
Clearer days are ahead... I'm holding fast to my July 2nd, 2016 prediction. ;) :lol:

CraigFair Loc: Santa Maria, CA.

Amen to not leaving my mount out even covered right now, as you say too much condensation.
I did get a weather alert sunny skies Sunday :thumbup: :thumbup:

SonnyE Loc: Communist California, USA

Yeah! .... uh, wait.
That's a week away!
:cry:

CraigFair Loc: Santa Maria, CA.

Ok, I know it will be sunny by Aug here on the Central Coast, with the June Gloom lasting from April to Aug.