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.)

A Certain Point of View on Pluto

Nine decades ago, the largest of the most distant objects in our Solar System was discovered by an observer in America.  Even today, it is still king over thousands of similar known objects residing past the gas giant Neptune.  All of these objects share many of the same physical characteristics.  Some leave their distant neighborhood to embark on a long journey towards and around our Sun, and are known as comets.

The discovery of this one object is a fascinating tale, for it was not found at random.  Neptune was discovered 75 years prior, and astronomers had noted over that time that Neptune’s orbit was not quite the same as the other three known gas giants (Uranus, Saturn, and Jupiter).  It was thought that a planet similar in size to Neptune and Uranus must lie just beyond the orbit of Neptune, pulling at Neptune via gravity.  And so a search was underway.

After its discovery in 1930, the newfound object was thought to be the solution to the Neptune orbit question.  As such, it had to be very large.  Soon it ranked among our Solar System’s magnificent residents.  In short order and for the next half century, it would be counted in science textbooks across America as one of the nine planets orbiting the Sun.  This harmonic order was solidified in schools and reinforced by all the amazing advances happening in science generally and our space program in particular.

Also during that half century, astronomers continued to learn and understand so much more about how our Solar System is built.  They realized, for one, that the inner four planets (Mercury, Venus, Earth, Mars) are a family of objects.  The outer gas giant planets, starting with Jupiter, are another family.  Each family was created in their own similar manners and composed of the same basic materials.

More importantly, the inner versus outer distinction among the planets is strongly related.  The four inner planets, being so close to the hot Sun, long ago burnt off all their access gas, primarily hydrogen and helium, to leave mostly their rocky cores.  The inner planets really are rocks, and we’re on the third from the Sun.  By contrast, the outer planets were not close enough to the Sun to burn off their access hydrogen and helium, so they remained, and still do, in their large, gaseous forms.  That is why we call them gas giants.

Like an ever-increasing jigsaw puzzle, more and more parts of our Solar System have been revealed thanks to advances in astrophysics.  How many parts to the Solar System are there?  Classically from ancient times, there were only a handful of planets, including the Moon and Sun.  For a while, in the early 19th century, there were more than ten planets accounted for, but eventually those newly-discovered objects, such as Ceres, were determined to be asteroids, a class of objects on their own.

Returning to the object discover almost 90 years ago, it was the first of the newest Solar System class, known today as Kuiper belt objects.

So we classify our Solar System roughly by five major object types:

  1. The center star, our Sun
  2. The inner rock planets
  3. Asteroids, most predominant between the orbits of Mars and Jupiter
  4. The outer gas giant planets
  5. Kuiper belt objects, which include comets

Around the same time that this first and largest Kuiper belt object was discovered, an important cultural genesis was happening elsewhere.  Mr. Walt Disney was creating his beloved cartoon characters, which are still the core of his Disney empire today.  One of these was a dog named Pluto.

Thanks to the intersection of planets traditionally being named for mythological gods and Disney’s cultural phenomenon, a star, err…planet, was born.

First Impressions Are Everything

We all know today the cultural battle – and it is cultural, not scientific – around Pluto’s demotion from the ranks of the other eight planets.  What exactly happened, and why is it still such a hot-button issue?

Some 15 years ago, a group of scientists, including Dr. Neil deGrasse Tyson, whose writings on the Pluto affair I base much of this post on, created a museum exhibit in New York to show the scale of the entire universe.  When it came to the Solar System part of the exhibit, being good scientists and knowing how Pluto is best classified as a Kuiper belt object, they placed Pluto not with the other eight planets, but with the Kuiper display.  Their exhibit made no specific mention of why Pluto was not in the planet exhibit.

This was mistake #1.  Culturally, Pluto has been ingrained into every school student for the past 60+ years as one of the nine planets.  Pluto was a planet just as the Sun rises and sets each day – it was taken for granted and never questioned by the general public, because they were never given a reason to question Pluto’s status.

But during that 60-year span, astrophysicists gradually realized that Pluto was not like any of the other planets.  It is mostly ice, smaller than Earth’s Moon.  If Pluto was ever near the Sun, it would form a tail, just like a comet, because Pluto is essentially a comet that never gets close enough to the Sun to start melting off its ice.  Its chemical composition is unlike the eight planets as well, but it is similar in makeup to the other Kuiper belt objects that reside at the farthest known space of our Solar System.

So it was obvious in the field of astrophysics that Pluto was unique and separate, but scientists never made mention of this (certainly not enough to change Pluto’s textbook status as a planet), particularly in their universe museum exhibit.

A reporter for the New York Times saw the exhibit, noted Pluto’s exclusion from the other eight planets, and wrote a sensational published article on how scientists unilaterally decided to demote Pluto.  At that point, scientists lost the battle for the narrative, because they allowed someone external from their profession to control it.  Dr. Tyson claims the exclusion was innocent and not intended to offend, but this reaction only reinforces a problem scientists have even today – they don’t understand that their knowledge has the power to upend common assumptions, and importantly, the aftershocks they can cause.

People prefer stability over change.  In a chaotic world, they look for constants.  The basics of what every contemporary adult man and woman was taught in elementary school is like a sacred foundation.  What happens when you tell them 2+2 no longer equals 4?  That is how most everyone reacted to the news that Pluto was, effectively, no longer a planet.

Digging a Hole

Like you, I grew up believing Pluto to be the ninth planet of the Solar System.  Like you, I was affronted when the news about Pluto’s apparent demotion began circulating.  And like you, I was even more upset when I heard, about a decade ago, that a group of scientists “officially” decreed Pluto no longer a planet.

Dr. Tyson is correct in that if Pluto was not named after a Disney character, the storm around its planetary status may never have gotten so big.  It may have flared and then subsided.  But Pluto is not just a planet to most, it is a beloved planet.  The sacred textbook matter is reinforced by the public’s fondness for something named after a Disney character.

The official reason and decision on Pluto only made matters worse.  This was mistake #2.  First, nobody (in the general public) is going to be swayed into rethinking Pluto because it has not cleared its orbit of debris.  That may make sense to an astrophysicist but not to a New York Times reporter.  Secondly, the problem was only compounded by calling Pluto no longer a planet, but a “dwarf planet.”

With apologies to Snow White’s hardworking miners as well as Gimli, nobody and nothing ever wants to be relegated to the status of “dwarf.”  Yesterday, you were an apple.  Today, you are a dwarf apple, because scientists say so.

The optics of calling Pluto a “dwarf planet” are horrible.

Fruitless Amends

After reading Dr. Tyson’s full explanation, I am thoroughly convinced Pluto is not a planet like the four inner and four outer planets.  I contend that any reasonable person who reads Chapter 9 of Dr. Tyson’s co-authored book Welcome to the Universe will agree as well.  There was no ulterior motive, no political agenda in demoting Pluto.  It was not about making our knowledge of the Solar System fit to keeping Pluto a planet, but recognizing that today’s accumulated knowledge puts Pluto into another class of object.

Mistake #3 has been the ongoing attempt by scientists to make some sort of compromise classification of Pluto, to return it to full planet status.  This is an Occam’s Razor matter – any new, refined definition to make Pluto a full planet again comes along with its own complications.  Pluto is the largest and most famous Kuiper belt object.  That is a grand status on its own.  But status is not science.  So why are scientists trying to “save” Pluto?  Perhaps for the fame of being the savior of a cultural icon is my guess.

I will not say, “Scientists should have done X, Y, and Z to have avoided the Pluto public relations nightmare.”  The Pluto matter is about the need for scientists to understand the enormous power they wield, especially as science itself becomes more potent in challenging long-held beliefs.  This is particularly true for how scientists communicate their knowledge to the public at large.  “You don’t have that option,” to not believe what scientists tell you to believe is no way to dispel the stigma of scientists being arrogant, over-educated fools who want to be your new high priests.  Science may be objective, but scientists are still human, complete with their own failings and prejudices.  That public figures like Dr. Tyson don’t appreciate their own complicit role in Pluto’s problem is one example of how scientists have to change their strategy for convincing the general public that the causes of science are sincere and real.

Dr. Tyson is likely very much aligned ideologically with his childhood hero, Carl Sagan.  Sagan, however, had a demeanor and way about him that invited everyone, regardless of their beliefs, to the knowledge of the cosmos.  It is to Sagan’s approach that I would look for the communication answers, not to the contemporary scientist’s abrasive method.