Tuesday, October 29, 2013

Complete! IAS Novice/Urban Observing List for October 2013

After failing to observe 6 out of 11 objects last month, this month I wanted to redeem myself. I got 4 right off the bat, and added the last two just in time before the end of the month. These Indiana Astronomical Society observing lists are a great way to learn about new objects, and stay motivated to get the gear outside.

Acquisition details are located on the individual blog posts (linked at the bottom).

8 Lacertae, Double (Quadruple) Star in Lacerta

Completing the October IAS novice/urban list this month with 8 Lacertae (8 Lac) a double ::cough:: quadruple star in the constellation Lacerta (the lizard). A lot of the doubles on the list this month were too close to resolve with my camera lens or telescope at prime focus.

My Canon Rebel XT at prime focus on the Meade 285 can resolve a separation of 14.4" (arcseconds), and my camera maxes out around 28" with a 300mm lens.

8 Lacertae
Background: 12 frames stacked in DSS, each at 300mm, f/5.6, ISO 1600, 1.3 sec; Callout: Single frame cropped and enlarged in Photoshop

This was another time-consuming-but-moderately-worth-it preparation layering an enlarged (400%) single frame over a single frame, over a stacked image to try to provide the sharpest view of the double star possible, while providing some context. It's more interesting that just looking at two dots against an all black background, while avoiding star trails at the same time.

I think I'm going to try to do something like this with all my double star photos (if I have time).

Spotted Gassendi Crater for the IAS Observing List

The monthly IAS observing list usually includes two lunar features - one 1st quarter and one 3rd quarter. Unfortunately the 3rd quarter moon means either waking up early or going out in the middle of the night to really get a good shot.

Here are photos I took early in early morning and late morning in the past few days. I was able to identify Gassendi Crater from the photos through my 300mm lens, but it wasn't quite as nice as observing the moon through my telescope. I did get my scope out intending to take a photo of the day moon, but there was no contrast and it wouldn't have been worth all the trouble.

Gassendi Crater is a large old crater that was filled in the lava, giving it a flat bottom and shallow rim considering its diameter.

(Left): Stack of 20 frames, each at f/11, ISO 200, 300mm, 1/100 sec through thin clouds around 7:30am
(Right): Stack of 10 frames, each at f/11, ISO 100, 300mm, 1/200 sec above the West horizon at 10:50am

Now that my expectations for moon photo crispness have risen, these photos seem to "do the job" when it comes to checking this crater off my list, but nothing to write home about. A year ago I would have been pumped to take either of these photos, but I've come a long way!

-4.3 Magnitude Venus Shines at f/11

I was getting ready for the ISS pass last night, and I couldn't resist getting a quick shot of Venus blazing at magnitude -4.3 to the SW. I didn't realize it at the time, but I left my camera settings stopped down from a previous moon photo, and was shooting at f/11. Smaller apertures (higher f-stop numbers) can produce sharper images but let in less light. They also seem to create these starburst patterns around bright lights.

-4.3 Magnitude Venus at f/11
Single frame with Canon Rebel XT, ISO 400, f/11, 35mm, 4 sec
venus starburst
Same image of Venus cropped to 100%

-3.4 Magnitude ISS Pass over Central Indiana

Last night, the International Space Station made another super bright pass over my apartment in Brownsburg, Indiana. It came out of the NW sky, flying directly toward my apartment balcony, and maxing out at an altitude of 83° above the horizon (almost directly overhead).

I got as much of the pass as I could from my balcony. I used my wide angle 18-55mm lens (18mm) to get as much of the sky as possible in frame.

After the ISS went over the roof, I took my dog outside to watch the rest of the pass overhead. I got a call from my brother who was outside watching as well. He said it was his first time spotting the ISS thanks to my text message a few minutes before the pass began. Neat!

space station fly over
Stack of several 10 second exposures at ISO 400, f/4.0, 18mm. I filled in the small gaps between frames in Photoshop to make one continuous trail. 
I left my camera out after the pass to get some star trails (and just in case, you never know what interesting thing you might catch in the night sky). I ended up with a bunch of planes and helicopters. It looks like way too much work to clean up to get long trails with just the ISS pass. That's what happens when you live near an airport and about a dozen hospitals.

The next morning I noticed a lot of contrails overhead - more than usual anyway. I snapped a pic and noticed later on that the skies look remarkably similar (except for the stars of course). I guess day or night, the sky is a busy place.

busy sky
Stack of 509 frames, each at 10 sec, ISO 400, f/4.0, 18mm - next to single iPhone photo
I really like how the sunlight is lighting up the fountain, and some birds flew into view to add to the busy scene

Check the website Heavens Above for ISS predictions in your area. Remember, it's going around our planet every 90 min or so, but it's not always catching the light.

Monday, October 28, 2013

Daytime Quarter Moon with Plane Contrail Alignment

Today I learned all about contrails! Contrail is short for condensation trail. These white streaks form behind jets in the sky when water vapor from the engines freeze into tiny ice crystals suspended in the air. They don't just look like thin clouds, they are actually man-made clouds, and made from the same stuff as regular clouds.

I always love a good alignment! The tiny moon and thin contrails from a jet in the same place at the same time, from exactly my perspective on the ground, in the entire sky, just for a split second - it feels like a special moment. 

jet contrails over moon
Jet contrail alignment with quarter moon. It looks like the contrail is holding the moon up, or maybe the moon is sliding down a cloud slide!

I learned that the contrails in my photo of a plane are "exhaust contrails" - but not exhaust as in smoke or pollution, merely that the water vapor is in the air coming out the back end of the engine's turbines. Contrails can also form from a temporary drop in air pressure as the air runs over the wings. These are known as aerodynamic contrails.

plane contrails
Icy exhaust contrails through my 300mm lens, cropped in Photoshop. This is the same plane that made the contrails in the photo above! The plane didn't cross the moon, but the contrails blew into position.

Notice the gap between the engines and the contrails. The water vapor coming directly out of the engine is super hot and invisible. You can't see the trails until they condense into water droplets and then freeze. Visible steam is actually billions of tiny water droplets suspended in the air. Water vapor itself is completely invisible. I learned something!

Is there a blog dedicated to contrail science? Why yes there is: ContrailScience.com

Sunday, October 27, 2013

Meteorite Identification Kits and a Russian Celebrity

Last night the Indiana Astronomical Society hosted a presentation on meteorites by Dr. Fritz Kleinhans, associate professor of physics at Indiana University-Purdue University Indianapolis (IUPUI).

I arrived late because I had trouble finding the Holcomb Observatory and Planetarium on campus at Butler University. I also had to drive slow because there were a lot of college Halloween parties going on and pedestrians were darting out of the shadows all around me!

Fritz brought these kits of samples, and we got to identify 4 meteorites from a lineup of 6 objects. He had 30 kits for us to use, that's a lot of meteorites!

meteorite identification kit
Identifying meteorites with magnets and physical characteristics
chelyabinsk meteorite
From Russia with love!
A piece of the Chelyabinsk meteor that lit up the Russian sky in February of this year. This meteorite, from Fritz' personal collection, must have cost a pretty penny! The Chelyabinsk meteor was a once in a century event, and is the most-photographed meteor air burst in history.

I also won a door prize, a copy of The Universe and Beyond 4th Edition. Woo!

Friday, October 25, 2013

From iPhone Video to AVI in Registax to Clean Moon Photo

I finally found a way to convert my iPhone videos to a format that Registax will accept (Apple BMP compression .avi files) and stacked a 3 second video taken with my iPhone mounted on tripod looking down through my telescope eyepiece (900mm/25mm = 36x). Here is a screenshot from the video (before) and a final processed image (after). Not bad for a phone!

quarter moon screenshot
Screenshot of a 3 second video taken with iPhone (Before)

quarter moon stack iphone
Final photo after converting, aligning, stacking, and adjusting wavelets in Registax (After)

The conversion software I used is called MPEG Streamclip by Squared 5, and it's a free download for Mac and Windows. However, the videos only worked for me on my Mac (could be something to do with a codec, not sure). Here are some sequence screenshots of the easy conversion in Streamclip

mpeg streamclip
If the preview image doesn't show up in the window, you know right away it's not going to work. On my PC, this preview window is all solid white with no image. This screenshot is from my Mac - and the conversion is a breeze!

mpeg streamclip
To convert to .avi file, go to File > Export to AVI

mpeg streamclip
Adjust your parameters. I chose to turn the audio off because I don't need it, chose to compress using Apple BMP, unscaled frame size, and drag the quality meter up to 100%
The resulting AVI file is huge! My 3 second video clip was 682 MB as an AVI file, and a longer 15 second video was 2.6 GB as an AVI file. I didn't notice a drastic improvement between the 3 second and 15 second stacks (about 115 frames vs. 454 frames) - if anything it just gets messier trying to align even more for not much more detail.

Saturday, October 19, 2013

Venus and Antares

venus and antares
75mm, 2.5 sec, f/11, ISO 200
I took this photo of Venus alongside the red giant Antares last night while I was waiting for clouds over the penumbral lunar eclipse to pass. I didn't realize that my focal ratio was still stopped down, but I noticed afterward that it created a cool radial diffraction pattern around the street light and even Venus itself.

I'll have to keep this in mind and try some "starburst" star photos with cool lens flares around them.

Hopefully this photo uploads uncompressed. I got in a fight with Google+ last night when I realized they were compressing, resizing, and "image enhancing" all my photos. I don't spend time out in the cold playing with different exposure settings just for Google to "enhance" and re-color my images. This seems like something you should have to opt-in to, not something they turn on by default.

Friday, October 18, 2013

Tonight's Penumbral Lunar Eclipse, October 18, 2013

Penumbral Lunar Eclipse, October 18, 2013
Penumbral Lunar Eclipse, October 18, 2013

Hooray! I got both photos I wanted. Kinda underwhelmed with this partial eclipse, but it's fun to do a side by side comparison. I had to get my gloves and winter coat out for these, a little preview of winter observing fun ahead!

Canon Rebel XT on fixed tripod 300mm f/11 1/250 sec (during) 1/400 sec (after) ISO 200.  Stack of 20 images each in Registax, desaturated the yellow out of the image from 7:55pm when the moon was lower in the sky. Planned to take both at exact same camera settings, but brighter full moon higher in the sky required faster shutter speed at same f-stop and ISO.

hunter's moon rising
An orange Hunter's Moon rising

I also grabbed this image of the moon when it was first peaking up over the apartments, it appears orange for the same reason sunsets appear orange, because it was still very low in the sky and the light had to travel through more of the Earth's atmosphere. 

moon over apartments

moon in clouds
Had to wait for the clouds to clear before shooting the partial eclipse, just to make sure I wasn't mistaking clouds for the Earth's shadow
Canon rebel xt night photography
iPhone photo while waiting for clouds to clear

Blurry Star Trails Reveal True Star Colors

true star color blur
192 frames stacked in StarStaX, 300mm, f/13, 30 sec, ISO 1600

Intentionally blurry star trails show a greater contrast in true star color. The amber stars have cooler surface temperatures, and the white and blue stars are much hotter. The segments are the distance stars appear to travel in 30 seconds, and the gaps occur as the Earth turns between consecutive photos.

I left my focus intentionally blurry to average the light and spread it out over more pixels in order to photograph the true color of the stars. If light is sharply focused into a point of just a few pixels, the RGBG Bayered sensor can change the apparent color based on the point it hits on the sensor rather than the actual color of the light. If you spread the light out over a larger area, this is less of a problem.

Oops, just realized I left the camera at f/13 which might explain why I had to crank the ISO up to 1600 to see any trails. I thought it was just because they were blurry they weren't showing up as well - but this explains it! No light getting through!

star trails and camera
Picture of a picture: 100 frames with my point and shoot looking up at the DSLR

Another Fantastic Indiana Sunrise

amazing Indiana sunrise
Amazing sunrise taken with iPhone

I went to let the dog out on Tuesday morning, and when I turned the corner I saw this! I immediately grabbed my iPhone from my pocket and snapped some pictures. I tried to balance the light by tapping on the brightest part of the sky to show all the amazing color details.

amazing Indiana sunrise
Not sure why this one looks HDR, it doesn't look like this on my phone
Same photo after I turned off Google+ auto image enhance

2 minutes later, the light had changed the magnificent sky into a regular sunrise. What is up with these uploads? These last two photos look blown out in HDR but they definitely don't look like that on my phone. Hmmm.

Tuesday sunrise
A few minutes later and the sky was back to "ordinary Tuesday sunrise"

Then, just a couple days later on Thursday, we had rain and overcast during sunrise - which resulted in this strange pink glow. It was like night and day (ok technically that's what a sunrise is), so I used my iPhone panorama to show the change in sky color panning from East to SW. 

rainy sunset
Overcast rainy sunrise on Thursday

Monday, October 14, 2013

Stopping Down and Stacking Moon Photos: Experiments at f/5.6, f/11, and f/13

Recently, I came across a site that talked about how stopping down the f-stop can help increase sharpness. I wasn't sure if this applied to astrophotography or lunar photography, so I asked the r/astrophotography community on Reddit. I got some helpful replies back that talked about the "Lunar 11" or "Looney 11 Rule," and a specific suggestion for stopping down 2 stops from wide open (so from f/5.6 to f/11 in my case).

sample moon photo at f/5.6 f/11 f/13
Summary sheet of my moon f-stop experiments with Canon Rebel XT

I gave it a try last night, and took a wide variety of exposure times at f/5.6, f/11, and f/13 to compare. I actually took test shots at every f-stop to experiment, and chose the best settings to go out and shoot stacks for my test.

variety of moon exposure photos
127 moon photos on my computer with different combinations of f-stop, ISO, and time

After selecting the best exposure times and f-stops, I went out to take a series of images to stack at each setting. I auto-focused on the moon in between each exposure change. I took 30 consecutive frames of each and loaded them into Registax. I manually chose 5 alignment points on each set, and used the same alignment points for each. I adjusted the first Wavelet slider to exactly 18.0 for each one (I don't know what the Wavelet units are, but if you use Registax you know what I'm talking about). I didn't do any post processing (other than stacking), so that means no additional sharpness, contrast, or color changes after using Wavelets. I tried to be as consistent as possible for a fair comparison!

Conclusion: I can see a little improvement after stopping down to about f/11 or f/13. I think the differences would be more noticeable if I had higher resolution photos (I'm shooting at 8 megapixels). It's really hard to tell any difference - but then again it doesn't take any extra work to shoot in f/11 rather than f/5.6 except I've sorta already learned the right kind of settings to guestimate ISO and exposure time at f/5.6 so I'd have to re-learn it at f/11. Sigh. This is a lot of effort for a little improvement, but I guess that's the name of the game!

Sunday, October 13, 2013

Photo of the Space Station on iPhone

I snagged another photo of the ISS tonight - this time a little closer to the ground to provide some nice foreground context. Last time I ended up with a nice bright trail but not a lot of context. The best app to photograph the space station is definitely Slow Shutter Cam (). You can use a headphone shutter release and just let your phone sit there until the ISS flies into the field of view.

space station iphone
ISS taken with iPhone and Slow Shutter Cam app, October 13, 2013 at 7:45pm

how to photograph space station iphone
Slow Shutter Cam, Apple headphone (shutter release), travel tripod, and a Diet Sierra Mist

International Observe the Moon Night at McCloud Nature Park

Well McCloud Nature Park has certainly been living up to its name, with hazy to straight up overcast skies all 3 times I've been out. Last night, there was a pretty good turnout from the public, but after a few quick views of the Moon, the clouds chased everybody away and we called it an early night.

star gazing
Night turns to twilight in this 8 second exposure. Luckily everybody kept pretty still!
sky and orange glow
Sky conditions and horizon orange glow light pollution (original color)
International Observe the Moon Night
20 second exposure of me and my friend John about to pack up, brightened in Photoshop.
International Observe the Moon Night
Obligatory "International Observe the Moon Night" moon photo

Jupiter at Prime Focus (900mm Meade Refractor)

I pointed my Meade refractor at Jupiter for the first time on Friday night to try to catch a rare triple moon shadow transit. Jupiter was too low to the horizon to see much detail, but I did try observing and imaging it with a combination of eyepieces and my camera at prime focus. It was obviously bigger through my 9mm eyepiece (which is rather dirty), but still nice at prime focus with my DSLR.

Since imaging at prime focus is much easier than trying to hover my iPhone over the eyepiece - and because I have more control over exposure this way - my prime focus images turned out much nicer. I stacked 9 of them with a longer exposure to create this composite of Jupiter with 2 visible moons:

jupiter 900mm
Stack of 9 frames, each at 1/15 sec, ISO 200, at prime focus on Meade 285 (900mm)

I observed some faint brownish red bands on the planet visually, but they didn't come out in the photos even after stacking. Not a bad first attempt - always room for improvement.

Tackling the October List

So far this month we've had some incredibly clear skies, and as many as 4-5 in a row. I've been getting out as often as I can, and started chipping away at the October observing list. I've got 4 down, 2 to go for a certificate, total of 11 objects, and 4 that are probably beyond my gear (so realistically 7 I could get this month). Here's what I've got so far...

Mare Undarum
Mare Undarum, first quarter moon, iPhone through Meade MH9mm eyepiece
Ok so it's not the best photo of the moon ever. I took it with my iPhone looking through the eyepiece of my Meade 285 refractor. I wanted to demonstrate that I know what sea I was looking at, instead of just taking a photo of the whole moon and pointing it out later in Photoshop.

I also took a video of the moon that night with my iPhone, but I've been having some difficulty converting the .mov file into an .avi that Registax can read. It's very picky, and I guess any .avi over a certain size forces the program to switch into a different setting. Yeah, I'll have to keep tinkering.

I also found out that the iPhone camera burst mode will not activate with the Apple headphones as a remote shutter release. I guess I could take rapid shots with something like Night Cap, but there's still the problem of holding the phone up to the eyepiece (or mounting on a tripod that is pointed down looking through the eyepiece, which takes forever to adjust).

NGC 7789 white rose cluster
NGC 7789, 73 subs, 54 darks, 67 bias, 300mm, f/5.6, 1.3 sec, ISO 1600

For having such a cool name, I was a little underwhelmed by the White Rose Cluster. It probably looks a lot better with faster glass and a higher resolution camera. It was easy to find right off of Casseopia Cassiopea Cassiopeia (ugh I can never spell that).

I'm not as excited about Delta Cephei (δ) as I am about 1) my new preparation of the final image, and 2) my new knowledge of separation in arcseconds.

First, to get double stars with just my camera and a lens (the easiest and therefore most likely way I'll shoot them) I just take a single shot and don't stack the images. When I stack them, I lose resolution and color, so the stars look like little white cotton balls instead of points of light. Ok, they look MORE like cotton balls, they're not very pointy as it is. In this image, I stacked the background but then cropped out the double stars from a single frame, so it's the best of both worlds: Context background stars and higher resolution double stars.

Second, after shooting and failing to resolve some double stars last month, I looked up which ones I managed to get and which ones didn't turn out. I figured out my gear's limit to resolving double stars, so now I know ahead of time which ones I should even attempt.

The separation limit for my camera with 300mm lens is about 28" (arcseconds) and the limit for my 900mm scope is 14.4" (arcseconds) at prime focus - presumably even less visually.

Here's C16 again for posterity, already described in a previous post

Friday, October 11, 2013

Superb ISS Pass Over Central Indiana Caught on iPhone

I found out about a prime International Space Station flyover about 30 minutes before it happened here in Indianapolis. The ISS was visible almost across the entire sky, and went 90° directly overhead, up past Venus and buzzing by Vega. I wanted to try to catch the pass on my iPhone using Slow Shutter Cam (), my Glif mount, and the Apple headphones as a shutter release. 

iphone 5 tripod mount
iPhone 5 mounted to a travel tripod using Glif tripod mount, Apple headphone shutter release, Slow Shutter Cam app
Venus with ISS, October 11, 2013; 7:43pm
I saw the ISS appear right on schedule, but I didn't see the small trail on my phone's screen. I thought for a moment that maybe the ISS was out of frame, so I stopped and repositioned my camera...

take photo of ISS with iphone
ISS crossing paths with a plane. This is a good example of how they look different - the ISS isn't blinking

I got this longer exposure of the ISS crossing paths with a plane. The ISS was brighter in the frame, but I wish I had stuck it out with the horizon shot a little longer. This angle lacks the context and nice colors of the sky near a dark horizon. Oh well, still fun to watch and photograph a -3.3 mag pass of the ISS with a camera phone. 

I also recommend this Precise Time app () that shows local and UTC time simultaneously. Fun for satellite spotting, or just being anal about having the correct time displayed in days and seconds. 

precise time app