Oregon Star Party 2015

Tags: astronomy

The Oregon Star Party (OSP) gathers every year in August in the high desert of the Ochoco Mountains in Central Oregon. This year it was brutally hot during the day and bone-chilling cold at night. In other words a typical year. Kat and I attended again this year so I wanted to capture the experience and document some of the sketches I made. First here is a gorgeous sunset taken from our remote 5,000-foot elevation base camp:

Of course the pretty colors came at a heavy price as wild fires continued to burn over 200,000 acres throughout Oregon. The fires at the Warm Springs Reservation directly to the west of us had already consumed about 55,000 acres. The dark orange sunlight had to refract through all of that smoke settling in the distant valley.

I like to do astronomical sketching. This trip I tried something new. I got a steel tripod easel from a local art supply shop and mounted a large clipboard on it so that I could sketch right next to the eyepiece. Sketching has helped me to learn that observing is a skill. It's a skill that you can develop. If you're an amateur astronomer and want to improve your skill at observing then I highly recommend sketching. It forces you to slow down and look. Really look. There's something about the tactile experience of making a detailed sketch that imprints a strong memory on you. When you look at a sketch you made a year ago you will remember the moment. 

A quick note on a religious argument about GoTo tech. I'm not against GoTo or PushTo scopes. That would be like being against a calculator because you can do long division by hand. But if you use them be very careful your observing doesn't devolve into a slap dash race around the sky checking things off as you go and treating everything like a spectacle. Slow down. It's better to spend 30 minutes on one deep space object than one minute each on 30 objects! If you're new to the hobby and don't know how to star hop then my recommendation is to put off GoTo until later. Lord Rosse was able to move his 16-ton "Leviathan" telescope with just two men! So consider first learning to do long division by hand and then get yourself a calculator later.

For the record I have a f/4.6 Dobsonian reflector with 356 mm aperture (14-inch) and 1650 mm focal length. 

The first sketch I'll show is an illustration of how faint and ghost-like some of these deep sky objects can be in an amateur telescope! This is globular cluster NGC 6522 which was discovered by Herschel in 1784. At 12 billion years old it is quite possibly the oldest globular cluster (GC) in the Milky Way galaxy. The age of the universe itself is estimated to be about 14 billion years old. About 16' away is an even fainter globular NGC 6528 shown here in the same field of view. To find it you have to go about 40' NW of Gamma Sagittarii (not in sketch).

This was sketched with a 31mm Nagler eyepiece which puts it at 53X in my telescope. 

If you're brand spankin' new to astronomy you might be wondering what is a globular cluster? It's a tight, gravitationally-bound group of stars that orbit the halo of a galactic core. That is to say they are satellites of a galaxy much like how moons are bound to their planets. We still don't know too much about how they formed. We do know that they are some of the first stars to form during galaxy formation. That makes them some of the oldest visible objects in the universe.

To compare let's look at a sketch of M13 (NGC 6205) in Hercules containing about 300,000 stars. If you know it's there and it's a very clear night you can see it with the naked eye. Here is the sketch with the same 31mm eyepiece (53X):

A bit of trivia. At a ceremony to mark the remodelling of the Arecibo radio telescope in Puerto Rico in 1974 organizers sent a 1,679 binary digit (10 byte) signal at a frequency of 2,380 MHz to M13. This is known as the famous "Arecibo message". M13 is about 25,000 light years away so why send a message there instead of Alpha Centauri or another closer system? Who knows. Maybe they were just testing the remodeled scope and wanted to do it with a bit of flair.

Onward to galaxies (from the relatively luminous to the very very dim)! Here is M51 which I observed and sketched both with my trusty 17mm Type 4 Nagler (97X) as well as my 9mm Type 6 Nagler (183X):

At my aperture I can't slurp up enough light to make 183X a better view than at 97X. But it helped me to see with averted vision M51's spiral arm structure. The smaller object to the north is NGC 5195, a satellite galaxy that passed close by M51 several hundred million years ago. The gravity from NGC 5195 has "warped" or pulled one of M51's spiral arms so that it looks as if they touch. There is a dark dust lane between the two so I was unable to see an actual connection.  

By comparison here's a sketch that Lord Rosse made in 1845 with his huge 72-inch reflector:

Rosse is definitely gathering more light than I'm able to gather! And yet he and other astronomers of the time didn't yet know what a galaxy was. He called M51 a "spiral nebula" as a result. In fact, it wouldn't be until Hubble discovered Cepheid variables in the nearby Andromeda Galaxy, which enabled him to calculate distance, that these "nebulas" were finally understood to be distant galaxies.

Now to the sublime with Stephan's Quintet (NGC 7317-7320), a group of five visually adjacent galaxies within 3.5' of each other in Pegasus:

Wait a group of five? Why are there only three very faint fuzzies over there to the West? Again I've reached the limits of the aperture of my scope. The sketch was done at 97X (with brief periods of chasing the ghosts of my imagination at 183X). Stephan's Quintet has a reputation for being notoriously difficult to find and so I'd never even tried to find it. But it was 01:00 in the morning and the viewing conditions were perfect so I thought "why not?" 

The trick to finding it is to look for the edge-on galaxy NGC 7331 first (sketched above as an inset). From there scan about a degree WSW. You might have to thump the side of your scope for the brightest one (NGC 7320) to stand out. I saw it first and then with averted vision was able to see two others. I could not split NGC 7318 so it was sketched as a single core.

One thing that bothers me in the sketch is I did not capture the drift and so now in the light of day I wonder if north is correct. My bad! I will need to go back to this in the future and verify the direction of celestial north. 

Last but not least is a part of the Veil Nebula in Cygnus. Here is NGC 6960, a very large, very faint supernova remnant that exploded over 5,000 years ago and spread steller debris over about 3 degrees of the visual field. 

It cannot be seen with a regular eyepiece. You have to use an OIII filter.  This isn't my favorite sketch and I can see the mistakes I made in using too much graphite in one part and not enough in another. One of the most difficult challenges in astronomical sketching is how best to illuminate your paper with just enough dim red light to be able to see but not so much that you disturb your night vision. I tend to err on the side of keeping it dim. Typically before sketching an object I will turn off all red light and just observe it for at least 15 minutes. I might stay at low power or try out higher and higher magnifications until I'm satisfied I have the right balance of surface brightness and detail.

You can literally spend hours observing the entire nebula. This sketch is just one part, nicknamed the "Witch's Broom" (or I've also heard the "Finger of God"). That bright 4.2 magnitude star above it is 52 Cygni. Actually 52 Cygni is a triple star system which has an angular separation of 6" (yes seconds). 

Finally here's me and Kat standing next to her beloved 120mm refractor on Day 6, sun-burned, dissheveled and in good spirits just waiting for the earth's rotation to cause the trailing edge of the Sun's disk to disappear below the horizon once more.