Saturday, July 30, 2016

#52 - Saturday, July 30, 2016

The weather looked like it was going to be partly cloudy and kind of iffy for this Camper Stargaze, so I just brought the 8-inch to see what could be seen in the patches of clouds.  However, it was quite clear until about 11:30 PM!  I was vindicated though when the clouds started coming over, however.  I was starting to regret not bringing along the 11-inch.   I showed campers Saturn, Mars, and Jupiter when it was visible through a gap in the trees, and then some of the club members and I looked at the Ring Nebula (M57), the Andromeda Galaxy (M31), the Trifid Nebula (M20), Swan Nebula, and Lagoon Nebula (M8), and globular cluster M22.  One of the members let me borrow an O-III filter when I was trying to find the Trifid Nebula – I was just able to make it out without it, but it was much easier to see with the filter.  The Lagoon Nebula was awesome in O-III.  I need to get one of those. 

           
I also took some Milky Way pictures from the tripod, which came out decently.  I’m going to use them as testbeds to figure out how to use Adobe Lightroom.  I also took some images of stars and clouds together, which had some cool effect.

Nikon D3100, 18mm @ f/3.5, 13s, ISO-3200

Nikon D3100, 18mm @ f/3.5, 8s, ISO-3200

Can’t wait to get a night of good weather, I need to image again!




Wednesday, July 13, 2016

#51 - Wednesday, July 13, 2016 - Astronomy On-the-Go: Extreme Edition

My sister Melody called me from the summer camp I used to work at [that she now works at] the week prior and asked if I’d be willing to come out to the camp while I was home visiting to do an astronomy night with the "Nocturnals" session.  I said, “Hellllll yeah!”  Then I started thinking of what I could do with them without my C8 [home is a plane trip away].  I’d bring my laser pointer and do some constellations, and also my little Meade binoculars and we could look at some star clusters or sections of the Milky Way.  I’d also bring my tablet and show them some of my astrophotos.  Cool.  So I started writing up a talk. Then, as a background process in my mind was thinking of additional toys I could bring, suddenly a realization hit me.  The guide scope, the Orion ST-80!  Of course!  I took off one of the rings and attached it to my camera tripod.  It held – it only weighs 3.5 lbs, not much more than my DSLR, which it can hold easily.  So I put it in my backpack to see if it would fit – it did!  So I wrapped it in bubble wrap and nestled it into the backpack beside my camera case, and I packed the tripod in my suitcase, one of my 90° star diagonals (the one for the Orion ST-80 is like a 45° one, better for mounting on the scope), the 2x Barlow, and the 25, 17, and 8mm eyepieces wrapped in bubble wrap and put into individual containers and then into my checked suitcase.  It was glorious.  I was so excited.   I was originally planning on coming out Tuesday night to the camp, but the Clear Sky forecast and the Weather Channel predicted that Tuesday would be kind of cloudy but that Wednesday night would be clear, so I changed to Wednesday.  Boy was that a good idea!  It was completely 100% clear the entire night.  Perfect conditions.  We ended up not getting up there until about 1:30 in the morning though, since the girls first canoed from main camp to one of the outlying cabin sites for a party that the counselors-in-training threw, and then it took a while to get them fed and get them started hiking.  It’s a little less than a mile hike up by my estimation – it takes about 20 minutes to make the climb.  I had the telescope, tripod, and all the accessories in my backpack (I also brought both my green and violet laser pointers, plus some red cellophane and rubber bands for the girls’ flashlights, all stuffed inside.)  I also had my tablet and my camera slung over my shoulders.  On-the-Go Astronomy: Extreme Edition!


Once we got to the top, I had one of the counselors help the girls put the cellophane on their flashlights while I set up the telescope.  The Milky Way was easily visible, and I quickly found the Big Dipper and Polaris to get myself oriented.  Unfortunately, I’m terrible at constellations, so all I could recognize was The Big Dipper, Cassiopeia, and the square portion of Hercules.  I wasn’t able to make out the teapot asterism of Sagittarius, but we may have been too high of latitude to see all of it.  Since we got up there so late, the Pleiades were well within visible range, so I made that my first unplanned target.  They looked excellent in the ST-80, and I’m definitely glad I bought a little finderscope for it too (same one as on my C8, but with a little dovetail meant for the ST-80).  I had to re-adjust the mount every other girl or so, which made it a little difficult to give a coherent talk, but it went smoothly enough.  After everyone had seen the Pleaides, I spent several minutes hunting down the Andromeda galaxy.  I knew it was off the bottom of the W in Cassiopeia, but I couldn’t make out the other constellation that made the line it lay on.  However, the FOV on that scope is large enough that I just needed to hunt around, and I eventually found it. Morning light comes early, so the sky started lightening at around 3:30 AM.  I hurried the last girls through.  I got a ton of really great questions!  They didn’t know much about space, but they asked excellent questions and follow-up questions, and they never stopped coming.  It was a group of about 25 girls.  It was a truly delightful experience!  I only wish we had more time, and I wished I had a goto mount, or at least a motorized one.  I’m going to look into getting a mini motorized mount for it, something I can pack in my checked bag, for just such occasions.  It was so, so awesome.

            
Besides that whole event, I also went down to the beach during the party and shot Milky Way photos from the beach.  In fact, the water was so calm that I went out on the dock, which had a better view.  I took a bunch of 20-second single images, as well as a stack of 15.  I focused by using a light on the far end of the lake, as far as I could see – bright enough to see in the Live View of the camera, where I can zoom in for critical focus.  I can’t lock down the focus, unfortunately, so I had to adjust it a few times throughout the night.  I used a new mini-tripod I got for the DSLR, since the one I had previously was not strong enough to hold it up.  It worked pretty well, but had a more limited altitude than I was hoping.  I’ll have to mess with it.  I edited the stack in Photoshop a bit, but none of the individual frames yet.
Milky Way from my old summer camp, Nikon D3100, 18 mm @ f/3.5
15s, ISO-3200
Milky Way from my old summer camp, Nikon D3100, 18 mm @ f/3.5
15x15s, ISO-3200
I really need a wide-angle low-f-ratio lens.  I saw some for less than $200 online.  I added it to my growing wishlist.
            

Saturday, July 9, 2016

#50 - Saturday, July 9, 2016 - First Anniversary!

Not only is this trip #50, but it is the one-year anniversary of my being an astronomer!  Averaging nearly once a week for bringing out the telescope is quite a feat. 
            
I got new ethernet cables for the CGE mount ($15 on Amazon for two-foot shielded ones), and they worked like a charm!  Telescope behaved properly all night.  And I do mean all night – I was up till 5:30 AM.  I ran the telescope on AC power, and the dew heater on high on the battery, and the battery still didn’t yellow-line.  I had to run the hair dryer twice though, even with the dew shield.  I’m glad the club has a few of those.
           
I didn’t start alignment and stuff until after the camper stargaze, so at about 11 PM; I brought my C8 for that.  I pointed it back and forth between Saturn and Mars, and delighted many children and adults with the view.  I love love love outreach.  I also put my camera on the tripod and ran around taking 4-8 second exposures of people looking through telescopes.  The only really good one I got was a posed one, since people tended to move.  But it was a fun experiment.  I may try flashing a light on them for part of the exposure so you can see both the people and the Milky Way behind them.  It was dark enough to make out the Milky Way that night, finally.
            
I worked on getting the guidescope working until about 1:30 AM.  The hardest part worked seamlessly – the camera talked to the computer, and the computer talked to the mount.  Even my test commands worked right the first time.  However, I didn’t quite get the camera going. I took a set of darks, but then the images were super grainy.  And I had no idea how to focus it, since defocused stars are too dim for cameras to see, as I’ve discovered with my DSLR.  But Will told me he drew a line on the focusing tube for where it should be, and that the noise will go away when it’s focused and has something to look at.  Then I just follow the procedure I found online for getting PHD going – it’s got its own built-in calibration process that measures how the telescope moves.  It takes about 5-10 minutes, according to the procedure.  So next time, I think I can get everything working.  And I’ll not use the Barlow to start with and see if the guiding is good enough despite the large difference in focal length and pixel size.
Celestron 11-inch SCT
Celestron CGE mount
Orion ST-80 guide scope
            
Since I couldn’t quite get the guide scope going, I shut it down and unplugged stuff, and just did unguided imaging instead.  I finally, finally got to image M20, the Trifid Nebula, on my own scope!  And it came out great!
M20 Trifid Nebula, Nikon D3100 on my C11, f/6.3 focal reducer, new 2-inch T-adapter for my DSLR
35x30s, ISO-3200
Buy on Zazzle

I enhanced the red a bit, since my DSLR isn’t IR-modified, but not too much.  I might mess with stylizing my images later.  I'm still figuring out Photoshop.  I’m pretty pleased!  Hopefully with guiding I can get more of the blue portion. 
            
I was up late enough that I also did a set on the Andromeda galaxy.  This one will need guiding to get the finer detail with longer exposures.  I’m also planning on imaging it through the guidescope itself in the near future.  Will showed me one of his images through it of M31, and you can easily see M32 as well, there’s not really any color aberration (since it’s a doublet, so two colors are corrected), and the coma is definitely visible but not terrible.  He says they make field flatteners for small telescopes like that too.  So this still isn’t quite what I want, but it is very promising.  It’s a large improvement over the C8, since there’s no field rotation and I’ve got a larger FOV with the focal reducer.  I did have some severe problems with either collimation, heat current, or non-orthogonality of the camera chip, or something.  I did collimate it, and stars looked good in the eyepiece.  I might need to collimate it with the camera on instead, which will be more difficult because it’s awkward to look through the viewfinder. 
M31 Andromeda Galaxy, Nikon D3100 on my C11, f/6.3 focal reducer
88x30s, ISO-3200

Another big improvement is I started using a 2-inch adapter for the camera, which attaches to the rear cell and not the visual back, as opposed to the 1.25” adapter I was using before.  I think the chip is bigger than the 1.25” adapter is.  It greatly reduced vignetting.  Below are the flats for comparison – left is the 1.25”, and right is the 2” adapter.

The reason why the right image is blue is because I used the sky rather than the LED spotlight on the battery to illuminate it.  I don’t think DSS cares whether the spectrum is white.  The histogram still had a nice central peak.  Part of the reason why my Trifid images came out so well I think is the less severe vignetting.  Even though DSS can correct for it, you can’t get the signal back that you lost in the first place.
            
Equipment fever is starting to hit me hard!  Can’t wait to save up for a nice CCD for DSOs.  Will definitely get the QHY5 soon as a guide camera and planetary imager.  Hopefully I can find one on sale on Astromart or CloudyNights before the Saturn and Mars set.  Jupiter is already gone.




Tuesday, July 5, 2016

#49 - Tuesday, July 5, 2016 - A Cloudy 4th of July Weekend

It ended up being cloudy the rest of the long weekend, unfortunately, so I didn’t get to try my C11 again.  Instead, and since it was a week night, I set up the C8 in the front of my apartment and took some video on Saturn and Mars.  I was going to do Jupiter too, but by the time I was set up and had Jupiter centered, it had just started to dip behind the roof.  Darn.  I’m going to have to set up earlier or move to another spot if I want to get any more images of Jupiter before it sets for the year.  I haven’t finished processing all of my videos, but Saturn was looking excellent that night, especially visually.  With a 13mm lens and a 2x Barlow, the Cassini division was readily apparent, and I could make out some banding in the clouds.
Saturn, Nikon D3100 on my C8, no focal reducer, 2x Barlow
12,203 frames stacked, unknown ISO and shutter speed
[You never need this many!!]
These are both easy to see in the image as well.  My mom commented that it looks like the rings are glowing.  Saturn is easily my favorite planet.  It is such a treat in the eyepiece, and comes out well in images too. 
            
The C8 has been acting up a bit too – both at the county park the other night and on this outing, after moving the object I’m looking at, it continues moving for a bit after I let go of the button.  I don’t hear the gears move, and it’s much faster than normal backlash – as in, it’s faster than sidereal motion during the time that the slack in the gears is being taken up.  It’s also smoother than that, and it starts slow, gets fast, and then slows again.  In my head, I call it “drooping,” since it seems like the telescope is drooping after I slew it in order to cause this motion or something.  It only happens in altitude.  I haven’t yet determined which direction it happens in – the slew buttons switch direction for slower speeds and I can’t keep track – but if I recall correctly, the object (Jupiter in the west) would appear to move upward after I let go of which button I was pressing.  I tried adjusting the anti-backlash, but that ends up taking up too much slack and the object jumps around.  I’ll have to mess with it.  I suspect I’m not using the right final two movements during alignment – I have to check my notebook, since I can’t remember and it’s different than the C11.



Friday, July 1, 2016

#48 - Friday, July 1, 2016 - When In Doubt, Borrow Someone Else's Scope

The C11 was malfunctioning pretty terribly.  I put the guide scope on it, borrowed a 7 lb counterweight from Bob, and got it all balanced, and then got started aligning.  Its initial guesses were terrible, but I aligned it anyway, and then went through polar alignment, which was waaaay off.  So I tried it again, same result.  So then I took off the guide scope and kept trying, but it would just keep slewing past where the star was in declination during alignment, and I could hear the motors running at higher pitch than normal during some parts of the slew.  Around 2:30 AM, I finally gave up and plugged my camera into Bob’s C14.  I originally had the focal reducer attached as well, but I noticed that stars not near the center were really skewed – this was because his is the EdgeHD, which is already field-flattened, so the focal reducer (which is also a field flattener) un-flattened it.  It took a while to find the objects because his finderscope wasn’t aligned very well, but we eventually found the Trifid Nebula!  I took about 90 images on it, since the focal ratio is f/11 on his scope, so objects would be dimmer.  Despite the especially small FOV, it came out quite well, especially after some Photoshop!
M20 Trifid Nebula, Nikon D3100 on a 14-inch Schmidt-Cassegrain, no focal reducer
65x30s, ISO-3200
Had to use Super Pixel + 2x Drizzle mode because of odd star shape (wasn't quite focused)

Still a little out-of-focus, but I think I’m eventually just going to have to get an auto-focuser because the critical focus is to tight on SCTs that it’s nearly impossible to achieve perfectly visually.  This is 65x30s at ISO-3200.  I unfortunately had to use super-pixel and 2x drizzle in order to get them to stack because of the un-focusedness of the stars.  But stack it did.  I also grabbed some images of M13, the globular cluster, but I haven’t copied it over to my computer yet.  We went to sleep in our tents at around 4:30 AM.