Constellations IV: Scorpius Rising

Click for larger image.

From my vault of unpublished astrophotography, today I bring you a rendition from earlier this year of the constellation Scorpius.  I had been meaning to process this one for a while.  Days turned into weeks which turned into months.  An eclipse got in the way somewhere along the journey.  So here we are, mid-October, discussing a constellation normally thought of in the Summer.

I recall that it was still very early evening when I took the photographs which comprise this stacked image.  As you can see, my view was a tad narrow, but you can easily make out the side of Scorpius anchored by Antares.  To the top-left are two moderately bright stars, part of the constellation Ophiuchus.  If you imagine a horizontal line from the bottom of those stars in Ophiuchus to the top stars in Scorpius, then you are envisioning the Sun’s elliptic path in the sky.

Advertisements

Constellations III: Of the Summer Triangle

Click to see the full-sized hi-res image!

A few days after I searched for Pluto, I chose to forgo my telescopes for one clear evening and play with my digital camera.  The Summer Triangle is straight up in the evening sky right now for several hours after sunset.  As Jack Horkheimer used to say, “Keep looking up.”  This time, take his advice literally and you will see the magnificent asterism defined by the stars Altair, Deneb, and Vega.

This image was taken in a similar fashion to my prior wide-field constellation pictures, like Leo, where I took dozens of light, dark, and bias frames and then created a composite in DeepSkyStacker.  For this new image, though, I went a step further.  I have been searching for a way to accentuate the stars based on their brightness, short of manually blowing them up.  I believe I have uncovered a technique to get the desired effect.  You can easily make out the three main stars along with other stars/patterns in descending order from their apparent magnitudes.

I must admit that I was mildly shocked at how many stars are shown.  Are those really stars, or image noise?  As the images were taken straight up, to the darkest part of the sky, it seemed plausible.  Also, the Milky Way runs right through the Summer Triangle.  You cannot see the Milky Way in my picture, as I don’t think it is possible to capture in my light-polluted area without longer exposures and an equatorial mount.

In checking as many detailed online star charts as seemed reasonable, I do believe those dots are all stars!

Remember that an asterism is a pattern of stars, versus a constellation, which is a generally accepted “official” pattern.  The Summer Triangle is an asterism (a triangle, duh) but it has several constellations in and around it.  How many constellations can you see and name in this picture?

Meteor Hunting, 2017 Edition

No meteors, but how many constellations do you see?

August 13th, 2017, 04:30 a.m. local time

In what is becoming an annual event for me, this morning I got up at 4 a.m. to check out what I could of the Perseid Meteor Shower.  Though the sky was mostly clear lest a few stray clouds, the waning Moon’s brightness was the only unfortunate circumstance compared to last year’s.  Within about an hour I saw two meteors, a long one to the West and a short one close to the Perseid radiant point, very roughly between the constellations Cassiopeia and Perseus.

And speaking of constellations, I did set up my digital camera and took a bunch of long exposures in hopes of capturing a meteor digitally.  Unfortunately this did not pan out, but I did get some interesting and surprising wide-field views of an August early morning sky.

The above image is not stacked, just a 30-second exposure at ISO 3200 pointed at the Perseid Meteor Shower’s radiant point.  I can clearly see Cassiopeia and Perseus, as expected, but then I was surprised at all the other goodies in the photo.

The Pleiades was the first unexpected capture.  I thought my favorite little star cluster was too far East to be in-range of my picture, but there it is, sitting in the very corner.

(Yes, the Pleiades are not a constellation.  They are actually part of Taurus.)

Next I saw the bright stars of Auriga.  At first, I thought one of these was Venus, but upon consulting my sky map app, Venus was much closer to the horizon at this time, hence below my picture.

The extremely faint constellation Camelopardalis is also here.  Since this one isn’t exactly the hot topic of dinner conversations and cocktail parties, I drew it out for you and your friends’ reference, so you can indeed have something to gossip about at that next party.

Part of Cepheus is also visible.

The very last noteworthy object I discovered is Polaris.  So counting Ursa Minor, that’s seven constellations in one picture!  Below is the same picture with all these interesting sky objects called out.  I recommend clicking the image to enlarge it.

Click to enlarge.

Constellations II: Leo the Lion

Click to enlarge and discover many stars!

Five weeks.  That is how long I had to wait from my first session photographing Leo the Lion to my second.  That is how long I had to wait for a mostly clear night, but even then, in the early evening of May 29th, I just finished my shots in time before large clouds rumbled in.

Five weeks prior, on April 22nd, the skies were much clearer and Leo was still directly overhead.  But as that was more of a test-shoot, compiling light, dark, and bias frames with my Canon EOS DSLR camera, I wanted to get a second set to see if there was any noticeable difference in the final imagining.  In particular, I wanted to shorten the focal length from f/22 to f/14, about mid-range.

I don’t think the focal setting change made much of a difference, but at least I did learn a few more things about the stacking software, DeepSkyStacker.  For example, the stacking “Intersection Mode” works wonders if you have to move the camera a bit and to ignore the stray wisps of clouds.  I know now for future reference that the sky does not have to be perfectly clear, just clear enough.  I can also take as many light/picture frames as I want, so long as I keep the object approximately centered.  DSS figures out the rest!

The one aspect of this technique I wish I could improve is to highlight better the apparent magnitudes.  Regulus is the brightest stars in my picture, but you cannot tell.  I don’t want to faux edit the image just to make the brighter magnitude stars bigger, but I do want to research possible PSP techniques to highlight the bigger stars.

I am also amazed at how accurate the picture is.  Compare the above image with this star chart and you can mentally plot the smaller stars.  Pretty cool!

Constellations I: Testing Ursa Minor, Snagging Draco

Do you see Polaris, Ursa Minor, and Draco?
Click to enlarge to full size.

On Monday, the same night I photographed Jupiter and Io, I also set up my tripod and new digital camera.  I want to start taking wide-field pictures of the night sky.

As a test subject, I pointed at the Little Dipper.  On the digital camera, everything has to be set to manual.  The longest setup time was in getting the focus just right.  For this, I used the brightest “star” available, Jupiter.

I took 17 images at ISO 3200, 18mm, and 10 second exposures.  I then took eleven dark frames – same camera settings but with the lens cap on.  This is to ascertain camera noise.  Finally I took 14 bias frames.  These are dark as well – lens cap on – but very fast shots.  In reading up on this, it’s possible I did not need bias frames, but I used them anyway.

I put all these images into DeepSkyStacker, and the above is what I got.  This is not a very interesting part of the sky, and my light pollution does not help.  In Ursa Minor I can see Polaris and the two bright end stars, but the middle ones are more difficult.  Something like Draco I cannot see at all.  So it is remarkable what the camera can pull out!

I am pleased with the amount of stars I captured.  Can you see Polaris and Ursa Minor?  I also got all of Draco in this picture, which surprised me.  Do you see it?

If you are having trouble (like so many of my co-workers did), please see this cheat image I created.  I purposefully am not showing the image directly in the blog post, to give you time to first study the raw picture before looking at the “answers.”