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From my vault of unpublished astrophotography, today I bring you a rendition from earlier this year of the constellation Scorpius.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.

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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?

My Hunt for Pluto, Part II: The False Star

Figure 2.1: My sketch of the area surrounding Pluto on September 14th, 2017.

“I really want to try to find Pluto again one more time this season…If I do get a chance, I will post a follow-up next month.” – Me, August 29th

With the Moon safely out of the way and a clear sky opportunity available, last week I resumed my quest to find Pluto.  Much of this post relies on information from my first attempt last month, and so I will be referring to that post frequently.

Recall that I leveraged the easily recognized “teapot” asterism in the constellation Sagittarius to star hop over to the approximate location of Pluto.  The main anchor star in the area of Pluto, both last month and now, is Albaldah.  Albaldah and a few nearby neighbors are the last stars I can see unaided.  So targeting Albaldah with my telescope was the first order of business.

The journey past Albaldah was guided with the help of both the Stellarium app on my tablet as well as my prior post.  I should note here that the “app” version of Stellarium is far less detailed than the PC version when investigating such faint objects in small spaces.  Further, based on my two observation sessions, I now believe there is an error in the PC Stellarium map, which I will explain in a moment.

Using the same 2″ Q70 eyepiece as last month, I quickly found HIP 94372, the 6.35 magnitude “mini-anchor” star near Pluto visible only with my telescope.  From HIP 94372 I located the 8th-magnitude star pattern I nicknamed k-lambda, assuring that I was in the correct vicinity.

At this point I was aggressively looking at the images from my prior blog post, the Stellarium app, and my telescope eyepiece.  I decided early on that it would be best to switch to a higher magnification than the 2″ eyepiece allowed, so I changed to my 1.25″ 14.5mm Planetary.  This eyepiece illuminated a much clearer view around HIP 94372.

Then I began sketching, referring to Stellarium only to assure that I was still in the location I wanted to be and drawing at the correct perspective size.  In my drawing above (Figure 2.1) it is difficult to see which stars are faint and which were really faint to the point that averted vision was necessary to see them.  The three stars I labeled as #1, #2, and #3 were the brightest, forming a triangle.  The three arcs were the approximate boundaries of the eyepiece.

With my sketch partially done, I had to make an assumption – that the small star close to HIP 94372, identified only by the Stellarium PC version, does not exist.  This probably threw me off last month, at least a bit, in determining if I truly had seen Pluto.  It is listed at magnitude 9.10, which should be easily visible, especially at the higher magnification I was now using with the 14.5mm eyepiece.  A 9.10 star should only be slightly dimmer than k-lambda, as well as the three stars forming the main triangle in my sketch.  And the few stars I drew around HIP 94372 are extremely faint, well past magnitude 9.  So either this star does not exist or its magnitude is incorrect in Stellarium.

Figure 2.2: Is this star really there?

Returning to the Pluto hunt, I knew it should be located within the three-star triangle I sketched.  In the figure below from Stellarium, I edited out the false star, as well as flipped the image to correspond to what I drew at the telescope that night.  Pluto is represented as a very, very tiny dot:

Figure 2.3: Pluto and surrounding stars as shown by Stellarium for September14th, 2017.

Remember, again, that most of these stars are very faint.  To help gauge where Pluto might be, I imaged a micro asterism forming a dipper or serpent, which starts at the star HIP 94338:

Figure 2.4: Identifying the serpent and “bright” stars.

I could see this dipper easily at the telescope so long as I knew where HIP 94372 was.  I also knew, then, that Pluto had to be just below (actually above, but the telescope reverses the image) this dipper and between HIP 94372 and HIP 94338.

Did I actually find Pluto?  I identified, at the telescope, three possible candidates, all hard to see without averting my eye a bit.  That night while still at the telescope, I drew an arrow pointing to the one I thought was most likely.  The other two candidates were to the right, the nearest dots above and below the one pointed to by my upward sketched “likely Pluto” arrow (see Figure 2.5).

Here is my sketch again, this time with the serpent/dipper lined, the three bright stars circled in orange, and the dot most likely to be Pluto, as determined afterward by comparing to both versions of Stellarium (iPad and PC):

Figure 2.5: My sketch with the most likely candidate for Pluto circled in yellow.

The best way I can confirm/reconfirm which dot was Pluto would be to sketch the area around HIP 94372 once Pluto has moved significantly.  Unfortunately by next month (after the next Full Moon passes), Sagittarius and Pluto may be too low in the sky for me to draw again, mostly due to the impacts of light pollution as they near the horizon.  And so, true final confirmation may have to wait a good seven to nine months, as the Earth and Pluto revolve around the Sun, beckoning the dwarf planet back into our East sky by late Spring 2018.

My Hunt for Pluto!

On the evening of Friday, August 25th, 2017, I decided to take my homemade 10-inch Dobsonian out to my back deck.  The Moon was still young, so the sky would be fairly dark a few hours after sunset.  Paired with surprisingly cool August temperatures, it looked to have the makings of a great stargazing night.

It had been weeks since I last used the big “light cannon.”  A combination of summer temperatures and humidity, all sorts of nighttime bugs, and the pre-eclipse fervor put my normal telescope usage on hiatus.  I planned out what I wanted to see, leveraging Sky Map.  The star clusters in Sagittarius seemed like good targets, followed by other deep sky objects like the Ring Nebula.  And oh yeah, Pluto is in the sky, so for kicks I put it on the list as well.

I started around 10:40 p.m., after the Moon was fully set for the night.  I turned my attention first to the South and Sagittarius.  Its remaining time in the 2017 nighttime skies is fading, and it may not be practically viewable by next month from my location.  Unfortunately, I had no luck in pinpointing the several star clusters in the heart of this constellation, due to them being already low in the sky and overtaken by my local light pollution glow.

So I scratched the South star clusters off my list and decided to try Pluto next, since it was in the vicinity of Sagittarius.  I held little hope of finding Pluto, but felt the need to try anyway, as I have been wanting to for a while.  Locating a 1,400-mile long object over three billion miles away is not easy, to put it mildly.  This would be unexplored territory for me, requiring all my rudimentary stargazing experience to date as well as the power of my 10-inch reflector.

I started by locating the “teapot handle” in Sagittarius.  It is barely visible from my yard, but leveraging the brightest star in the area, Nunki, makes for finding the handle quickly.  Nunki’s apparent magnitude is 2.05, a little less than Polaris’s, to it is still within easy viewing at my location.

As of mid-2017, Pluto is above the Sagittarius teapot asterism when looking from Northern locations on Earth.  The closet bright star to Pluto is Albaldah, with an apparent magnitude of 2.89, so still easy to find.  Albaldah is directly above the teapot, as shown in Figure 1:

Figure 1: The Sagittarius “teapot handle” including star Nunki, with the Pluto guide star Albaldah above it.

Albaldah is more officially known as Pi-Sagittarii, and it forms a triangle with two other “Sgr” stars in the area, Omicron-Sagittarii and Epsilon-Sagittarii.  This triangle provides a visual cue to where Pluto should be in the August 2017 sky, to the left of the triangle, as shown in Figure 2:

Figure 2: The three Sagittarii stars and the approximate location of Pluto, circled in orange. Click to enlarge.

Assuming you are looking at the full image, you should see one brighter star within the orange circle along with two dimmer stars.  This brighter star is called HIP 94372, and with an apparent magnitude of 6.35, it is not visible to the eye.  So here is the leap from naked eye observing of the three Sagittarii stars to telescope viewing of HIP 94372.  Figure 3 below gives the Stellarium details on HIP 94372 along with an even closer view, now showing Pluto’s location on the evening of August 25th:

Figure 3: HIP 94372 with nearby stars, and Pluto on 08/25/2017. These are visible only with a telescope.

At this point in the observation session, I was heavily consulting Stellarium on my iPad, as there was no way to see the following-discussed stars unaided.  I leveraged my best-quality two-inch eyepiece, the 32mm Orion Q70 Wide-Field.  I post the name and link here not as an ad for Orion, but so you get a sense of the equipment used for this difficult exercise.  The Q70 is better than average as I have found that it significantly reduces the coma effect (blurriness around the edges) common in many 2″ eyepieces.  In hindsight and for next time, I should also have had at-the-ready a high-powered 1.25″ eyepiece.

To get a sense of the field-of-view through the Q70, I was able to see both Albaldah and Omicron-Stagittarii at the same time in the same eyepiece field, with each star near the edge on opposite sides.

It is important to note here that we are discussing the limits of common star map apps.  We are getting down to 10th and 14th magnitude objects, so the overall accuracy of the maps may start to get fuzzy.  I am not saying Sky Map or Stellarium are wrong, only that this exercise approaches the limits of their usefulness.  Because as I discovered, it becomes very difficult at these magnitudes to align the computer map with what you see in your telescope.

HIP 94372, at 6.35 apparent magnitude, is easily seen through a 10-inch reflector telescope.  The second-brightest star in this area is unnamed with an apparent magnitude of 9.80 (see Figure 4).  This was still very visible via the telescope but much fainter than HIP 94372.

Figure 4: Stars near Pluto, August 2017.

And so we come to the task of actually identifying Pluto.  At an apparent magnitude of over 14, is it visible at all from my Western Chicago suburban skies?  I could see, near HIP 94372, the ever-so-tiniest dot, which I assumed to be Pluto!  “Assumed to be” is key here as I cannot say for sure.  When you look at the Moon, Venus, Jupiter, Saturn, or Mars, you can say with 100% confidence what you are looking at.  But with Pluto, I am relying on approximations of a nearby bright star (Albaldah) to make even more approximations of faint star patterns seen only with a telescope.

Figure 5: Pluto’s location and details in Stellarium, August 2017.

I wanted to confirm my finding as best as I could, so I started hunting for noticeable star patterns in the area of HIP 94372 that I could recognize with the help of Stellarium.  Below and to the East I found one small set (see Figure 6).  But the “Rosetta Stone” was the pattern a little farther to the East still.  It is easily seen as a faint pattern in the telescope.  I call it “k-lambda” as I imagine it is the fusion of the letter k and Greek letter lambda in a Star Trek transporter accident. 🙂

Figure 6: Recognizable star patterns very close to Pluto in August 2017,

All of the stars in k-lambda are in the apparent magnitude range of 8.2-8.3, which make them faint but still easily seen in my telescope.  Figure 7 shows the details of one of these stars, called HIP 94784:

Figure 7: The stars of my k-lamba asterism.

Finding these stars seems easy with the hindsight of a few days.  It involved a lot of “feeling around” past Albalduh to get my bearings at the scope.  Even moderately bright stars are easy through a telescope, but going past that 6-7 apparent magnitude threshold was like walking through a forest at night with little-to-no light.

So by leveraging these two small and faint star patterns, mapped towards the “bright” faint star HIP 94372 and anchored to the naked-eye star Albaldah, I can safely say that I found the location of Pluto that evening, even if I cannot say for 100% certain that I saw Pluto itself.  See Figure 8 below for Albaldah, Pluto, and my k-lamba all in the same Stellarium image.

Figure 8: Click to enlarge.

I really want to try to find Pluto again one more time this season with the experience I now have.  Unfortunately the Moon is growing towards Full each night, which will make the evening sky too bright for such fine work over the next week and more.  I estimate the Moon should be out of the way again around September 13th.  By then, Pluto will have nudged a bit towards the West, as shown below in Figure 9.  If I do get a chance to try for Pluto one more time this year, I will post a follow-up next month.

Figure 9: Pluto’s location from Earth on September 13th, 2017.

Thanks for reading to the end!

(And yes, I did find the Ring Nebula after my Pluto trek.)

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.

Saturn in July 2017

July 16th, 2017, 11:10 p.m. local time

All the recent rain and generally miserable humid summer weather almost made me forget that there was a brief pocket of pleasant evening clearness just this past Sunday.  It was a great opportunity to move my 10″ Dobsonian to my back deck for taking in the evening’s astronomical wonders.

I started with imaging Saturn, my primary objective.  I had great difficulty locating Saturn that night and it was almost 20 minutes before I locked on.  Keep in mind this is all a manual process.  My homemade Dobsonian is a Newtonian reflector on a simple alt-az swivel mount.  Even by turning my exposures all the way up, I still had problems finding it.  The lesson here is that it may be next to impossible to attempt imagining of Uranus in a few months with my meager equipment.

Returning to the present though with Saturn, I think this may be my best yet.  When I image the planets, I always take a few sets of videos with different refocusing.  It is really, really hard to get the exact focus right, and the digital camera’s view screen can only get you approximately there, hence the need to take a few sets so that hopefully at least one of them is good.

This night, I took two sets, and it was the first group of videos that allowed me to create the above image.  I also used my Neodymium filter, which I prefer for Saturn as it brings out a nice color contrast among planet’s cloud bands and ring levels.

After my Saturn session was complete, I put a 17mm eyepiece on the scope just to look around on that clear no-Moon night.  Of note was the Hercules Globular Cluster (Messier 13) which I saw clearer than I ever had.  Wow!  I could make out many bright stars in the foreground of the cluster.  I don’t have the proper equipment to image it, but I hope to have the skills to properly draw it by next year.

Also of note was that I am starting to see Cassiopeia earlier and earlier in the Northeast.  It’s the great pointer to the Andromeda Galaxy.  My view to the East is mostly blocked, so I have to wait some before the galaxy is visible via telescope and binoculars from my backyard, but it is comforting to know my favorite gray smudge will be back soon!

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.”

Enjoying a Winter View of the Summer Triangle

March 15th, 2017, 6:20 a.m. local time

A lot of stargazing stuff happened on or around the Ides of March, and I am still getting caught up.

For a few mornings this week there was a predawn unexpected treat: the Summer Triangle!  I like that it is pretty much visible all year long, provided you are willing to stargaze at any time of the night.  Fortunately the current sightings align with the start of my daily routine.  Perfectly framed towards the East by my big maple tree were the stars Deneb, Vega, and Altair.

Here are is the same picture with each star’s name attached:

This picture was taken with just my smartphone.  Nothing special about the settings as I only wanted to frame the triangle correctly.

I should also note that this is not a light pollution-tainted image.  The Sun was nearly ready to pop over the horizon, so only the brightest stars and Jupiter were visible throughout the sky.