Friday, December 28, 2018

Surprisingly Easy

I wasn't expecting it to be easy.

Something always goes wrong with computer upgrades.  I'd better find some wood to knock on and ward off the jinx that will happen by even thinking that this upgrade was easy.

Some background first.  I purchased my astronomy laptop from Woot in December of 2015 shortly after buying my SkyWatcher Dobsonian.  It was on sale for less than $200.  I purchased it on a lark because it was so inexpensive and I had a little bit of budget remaining after my telescope related purchases.  I didn't really to expect it to be so useful as I gained skill with the telescope and imager.

It turns out that the laptop has been a real workhorse.  It has performed really well as my astronomy laptop.  With ASCOM drivers and Stellarium, it can control the telescope with ease over the Bluetooth link.  Also, not only has it helped me image planets and DSO's, it has done so under adverse seasonal conditions.  20 degrees (F) outside?  No problem.  Frost on the screen? No problem.  90% relative humidity?  It seems impervious to dew.

Why the upgrades?

Several times over the past year, the laptop has run out of disk space during an astronomy session.  This probably has something to do with my obsession with imaging Mars as it came into opposition.  😎 

There are few things worse than being outside with the telescope at 3am and having to make data culling decisions because the drive is full and there is more data that needs capturing . . .

And now, as I learn to use DeepSkyStacker, I need to keep the frames of data that I capture.  Usually, SharpCap deletes the raw data as it live stacks.  Frames of data from the ZWO ASI294MC imager are huge!

To do the upgrade, I purchased a solid state drive (SSD) from Amazon.


Thursday, December 20, 2018

Comet 46P/Wirtanen

On December 18th, 2018, Comet 46P/Wirtanen was naked eye visible from my backyard.  Just barely.  

If you waited for moonset and knew exactly where to look and used averted vision.  Yup.  There it was.  A dim grayish-green splotch in the sky.

It was even better when looking through binoculars.  It became a dim green blob.

Then, I aimed the 10 inch Dob at it.  It became a much bigger, brighter, but still dim green blob, but now with the increased aperture and magnification, I could see the comet's motion against the starfield.

Using the ZWO ASI294MC imager, I captured this.

46P Zooming by
This data was captured and live stacked with SharpCap.  It's 151 frames at 8 seconds exposure, each.  So, basically, this is a 20 minute exposure with the starfield being tracked so the relative motion of the comet is apparent.

What if I wanted to track the comet instead of the starfield?  It turns out that is a much harder problem.  The scope only has tracking modes for lunar, solar, and sidereal.

Monday, December 17, 2018

Happy Birthday

Well, it's a birthday of sorts, anyway.

This weekend marked the third anniversary of first light for my 10 inch SkyWatcher Dobsonian.

I thought of celebrating the occasion with candles, cake, beer, loud music, and dancing, but settled on posting some pictures of the telescope's arrival, unboxing, and construction instead.

The delivery truck unceremoniously dumped the boxes at the end of the driveway, but dear wifie dragged them into the garage for safekeeping until I could get home from work.  As delivered, there was a huge gaping hole in Optical Tube Assembly (OTA) box.  Not an auspicious sign, but it turned out that there was no damage.

The hole looks like a door flap.  What's up with that?

Sunday, December 2, 2018

Superhighway in Space

In last week's blog post, I shared an image of the Orion Nebula.  This image had an odd artifact of what appeared to be an implausibly thin high altitude jet contrail streaking across a corner of the nebula.

While hoping that I had indeed captured Marvin the Martian and his intergalactic space cruiser returning from one of his epic Earth plundering exploits, I did some research and found a slightly less "tinfoil hat" explanation for the contrail.

In his 1945 paper, entitled "Extra-Terrestrial Relays — Can Rocket Stations Give Worldwide Radio Coverage?", published in Wireless World magazine, Arthur C. Clarke gave wide exposure and details to the idea that satellites could be placed in geosynchronous orbit and be used to provide communications.

This orbit has come to be known as the Clarke Belt.

This is a screen capture from my LiveSky subscription, looking up toward Orion around midnight, December 1st 2018. (Click to enlarge.)

The Clarke Belt
The Orion Nebula is centered in this image and the Clarke Belt runs right through it!

The satellites are geosynchronous, but the night sky is not. So, the Orion Nebula moves behind the Clarke Belt and any cameras tracking it will capture the occasional smear of light reflecting off of the satellites.

This Youtube video shows it clearly.

Marvin, I'm still keeping my eye out for you.


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