StarWatch: Moravian University Astronomy

MAY 2026

MAY STAR MAP | MOON PHASE CALENDAR | STARWATCH INDEX | NIGHT SKY NOTEBOOK

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1550 MAY 3, 2026: Olber's Paradox: The eighth of sixteen children, Heinrich Olbers (1758-1840) was a physician by training (1780), but a skywatcher by heart. After 1820 he retired from medicine and devoted himself strictly to astronomical pursuits. He was the discoverer of five comets; the most famous was 13P/Olbers discovered in 1815, last returning to the sun in 2024, passing Earth as a 7.4 magnitude object. Olbers also recovered in 1802, Ceres, the first asteroid discovered by Giuseppe Piazzi in 1801. Then Olbers went on to find both the second minor planet, Pallas, in 1802, and the fourth asteroid, Vesta, in 1804. However, Olbers is most famous for the contradiction he postulated in 1826, known as Olbers' Paradox, which asked why the nighttime sky was not ablaze with light. * He surmised that in a static universe containing an infinite number of stars spread homogeneously across the heavens, every position in the sky should be occupied by a star. According to this model, the nighttime sky should be incandescent, not dark as we view it. A similar analogy might be the scene created in a dense forest where every line of sight parallel to the ground eventually converges on the trunk of a tree. * Our universe is not static or infinite, nor homogeneous in stellar distribution, but should the heavens not have some of the characteristics about which Olbers predicted, and be much brighter than it is actually observed? The answer is still no! * A minor contributor to a darker universe is starlight that is obscured by dust. Also in a huge accelerating system like ours, approximately 54 billion light years across, the energy from younger stars may simply not have reached us yet. The speed of light (186,282 miles per second) is fast by our standards of motion and a constant in space, but the time required for light traveling across the universe makes that speed seem more like the movements of a snail. * So what causes our universe to appear dark? It is the expanding-accelerating universe. This same expansion causes the electromagnetic waves emitted by stars to stretch or redden as they move away from us. The amount of redshift in a galaxy has been used for nearly a century to determine the size of our universe. Visible light is shifted into invisible infrared light, but then higher energy, invisible ultraviolet energy, is shifted into the visible. However, there is no gain here. * It is estimated that coolest luminaries, K and M-type hydrogen burning stars, make up about 90 percent of the luminaries in the sky. Their predominant energy production is in the invisible infrared (heat) portion of the electromagnetic spectrum and very little in the ultraviolet, about 0.00014 percent of the sun's UV production which is also very low compared to Sol's visible signature. M-type stars do flare in the ultraviolet, but in total, the redshift actually makes these very common, cooler stars appear dimmer in the light human eyes receive. Another way to look at this concept is to understand the relationship between wavelength and energy, as described by the German physicist, Max Planck. The longer the distance between wave crests, the redder the light becomes, and the less energy that specific wavelengths possess. So the redshift drains the entire amount of energy coming to us, causing the star or galaxy to become less luminous than it would be if we lived in a static universe. This is the predominant reason why the sky is dark. * By tapping here, you'll see a recent image from Australia that I took looking near the heart of our Milky Way Galaxy. It highlights Ptolemy's Cluster (M7) near the center, almost completely obscured by the background haze of millions of stars. The reddening effect of dust is also present on the left side of the image. At the far left, dust created by countless supernova events over the history of the Milky Way virtually prevents any light from escaping. Ad Astra!

1551

MAY 10, 2026: The Automated Telescope Revolution

When I graduated from Kutztown University in 1972, I purchased a used 3.5-inch Questar, a Maksutov-Cassegrain reflector, as a graduation gift to myself. It was the Cadillac of optical precision and mechanical excellence in the world of ultra-small telescopes. That scope in a shoebox, well rather a convenient cardboard container including numerous accessories, traveled with me everywhere as I embarked upon discovering and camping in America's national parks during summer vacations with my friend, Allen Seltzer. I did visual observing and some astrophotography through it, but mostly I piggybacked my camera onto the Questar, sometimes hand guiding my images. * Digital photography entered my realm of thinking 30 years ago. However, it was not until about ten years later in the early 2000s, that I adopted it for all of my photographic needs, eventually using Canon products. They had excellent sensors that had superb low light capabilities for the time. * Now after nearly completing a backyard observatory with a 17-inch, Dall-Kirkham reflector, I've been introduced to ZWO's Seestars and Dwarflab's family of fully automated telescopes. A half-dozen years ago, I saw other competitors starting to break into the automated observing/astrophotography marketplace, but I was not overly impressed with the images they had produced. That has all changed in the last several years. * I was first introduced to the Seestar 50 at a Hawk Mountain StarWatch event that I organized last August, then to the Dwarf 3 when Peter Detterline brought one to Iceland to record auroras with Jesse Leayman and me in late October of last year. Intrigued by the ease of setup and the quality of the images it produced, I decided that one of these scopes would become part of my astronomy lineup in the near future. Peter's Dwarf 3 was a point-and-shoot system that produced more than acceptable stills and videos for a system that weighed next to nothing while using a tripod for support. I opted to photograph the trip and auroras with a tripod mounted DSLR, Canon R5 Mark 2 camera, while Peter made videos and some stills with his Dwarf 3 system. We both got results that highlighted the beauty of the night sky. My most recent Icelandic land and sky images can be found here, along with a few of Peter's Dwarf 3 composites. I think you will agree that they both have their place in wide-field astrophotography. * When I returned home, I investigated both the Seestar 50 and the Dwarflab's smart telescopes. I settled on the Seestar line of automated scopes because the 50mm model provided a larger aperture which would give me better resolution, as compared to the Dwarf 3 which was only 35mm. Nevertheless since then, I have also purchased the Seestar 30 Pro which offers a much larger field of view and better AI processing. * I have also begun recommending these easy-to-use, automated instruments to enthusiasts who are eager to purchase their first scope. Yes, I realize the photons of light are being directed onto a sensor, and then sent to a tablet or a smartphone via Wi-Fi. However, when the starscapes obtained in just two minutes of automatically stacking and processing photos are better than what much larger aperture instruments can produce visually, along with a price point of under 600 dollars, it seems like a no-brainer to give these instruments a serious chance before purchasing a more expensive telescope for visual or astrophotography pursuits. After all, the best telescope is the one you use the most often, and for me that has become my Seestar line of instruments. Consider it. Recent astrophotos are here. Ad Astra!

1552 MAY 17, 2026: Under the Influence of the Flower Moon: Most of the time before writing a StarWatch, I spend a few minutes working with Software Bisque's The Sky and running through the week to make sure I'm not missing anything important. The events that I discovered for this week's blog proved once again that following the moon, in this case May's Flower Moon, could create some very rewarding sky views for the visual observer, as well as permanent memories for the astrophotographer.
Sunday, May 17; Extremely Young Moon Visible in the WNW: The 2.4 percent razor-thin, waxing crescent moon was new on May 16 at 4:01 p.m. Now less than 30 hours later, it should become visible 30 minutes after sundown, 8:45 p.m., 10 degrees above the WNW horizon. These moons are easiest to observe during late winter and spring when the orbital plane of Luna is tipped at a high inclination to the western horizon. The moon's pale, thin-lipped smile should first be revealed using binoculars, then as skies darken, look for earthshine on the unlit portions of the moon, where reflected sunlight from a nearly full Earth is mirrored back to us from Luna's surface. Also called the old moon in the new moon's arms, earthshine on a thin waxing crescent gives the moon an ethereal manifestation that becomes more vibrant during nautical twilight when the brightest stars of the evening first begin to peek from the heavens, but before the contrast between a darkened sky and a brighter moon is greater.
Monday, May 18; Young Moon Passing Venus Tonight: One day later, the 54-hour moon stands less than three degrees to the right of Venus at an altitude of 21 degrees. View 30 minutes after sundown. The Goddess of Beauty stands at magnitude -4.0, while the moon is at -7.1, 17 times brighter than Venus. This is actually a minor difference. The full Blue (full) Moon on May 31 will be 145 times brighter than it is on this evening. Smartphone images of the pair will easily reveal earthshine on the moon.
Tuesday/Wednesday, May 19/20; Moon Near Jupiter: The waxing crescent moon is positioned between Venus and Jupiter on the 19th, but favors Jupiter and is above Jove by nearly seven degrees on the 20th. Both evenings offer opportunities for wide-field photography and for the ability to incorporate land and sky in the images.
Friday, May 22; Moon Near Regulus: Last month, the waxing gibbous moon occulted Regulus, the alpha star of Leo the Lion, and right on cue, the weather went south. It rained! This month, the first quarter moon passes within three-fourths of a degree from Regulus, the brightest star of Leo the Lion. Unfortunately for us, that occurs three hours after it has set. At 10 p.m., the pair is about 3-1/2 degrees apart. Use binoculars for the best views.
Sunday, May 31; Blue Moon Near Red Antares: You can wait until 3:30 a.m. at the latest to catch Antares low in the SW, above and less than two degrees from the moon, or observe the pair about three-quarters of a degree farther apart in the early morning sky just after midnight. In both cases, Luna will be a Blue Moon, the second full moon of the month. This observation will be best seen with binoculars. You can also occult the moon with a distant tree, as I did on the morning of May 4 when Antares and the moon were separated by only 1.5 degrees.
Hoping everyone has pleasing views of the waxing Flower Moon this May. Ad Astra!

1553 MAY 24, 2026: Questar Passes into History: A news note from Sky & Telescope magazine, sent to me by Terry Pundiak, provided the culmination of rumors about the shuttering of Questar Corporation in New Hope, Pennsylvania. Questar closed its doors on May 4. * Lawrence Braymer founded Questar in 1950, after reading an article in the Journal of the Optical Society of America by Russian optician and astronomer, Dimitri D. Maksutov, who had written about his new mirror and lens design. Conceived in 1941, this new hybrid Cassegrain incorporated a meniscus to correct for the spherical primary mirror. Braymer envisioned this new blueprint as the basis for a compact, rugged, yet easy-to-use telescope. Released in 1954, the 3.5-inch Questar, Maksutov-Cassegrainian telescope, was crafted with care. It was marketed as a premium instrument for the discerning enthusiast, eventually becoming a collector's item sought after by amateurs, professionals, and even celebrities. Famous names, such as Wernher Von Braun, Arthur C. Clarke, Johnny Carson, and David Garroway were proud owners of Questar telescopes. Charles Bronson used one in the 1972 movie, The Mechanic. Even Al Nagler, founder of Tele Vue Optics and designer of ultra wide field eyepieces used in the Apollo program, owned a 3.5-inch Questar (credit for much of the last paragraph was from Sky & Telescope magazine). * However for me, Questar had a more personal significance because members of the Lehigh Valley Amateur Astronomical Society, Inc., my home club, owned Questars and were employed by the company. Questar gifted the LVAAS two of its Standard Model instruments in the 1960s which became rental telescopes that members could borrow for $5 a month. I happened to be successful in renting one of them to image and photograph my first total solar eclipse witnessed on March 7, 1970, in Lumberton, North Carolina. * But even before that, I was hooked on this instrument and had my sights on owning one, partially because of my association with LVAAS member, Paul Shenkle, who was sales manager for the company. Paul was a quiet individual who measured his words, a master optician, and highly respected among club members. I was grinding and polishing an 8-inch, F/7 primary mirror for a Newtonian reflector, a two-year project nearing completion when I joined the LVAAS in January of 1967. Paul Shenkle took me under his wing, coming to my parents' home to test the accuracy of my work. Upon his first examination, Paul found the edges of the mirror turned down and the center too deep. Teaching me a correction polishing technique to modify the mirror's curvature into a sphere, I was instructed to use this method for eight hours before he examined the mirror again. When Paul returned the following month with his Foucault tester, after only six hours of working the glass, he discovered that I had not only rectified the problem, but that the mirror was completely parabolized (corrected for astronomical use) to within a spectacular 20th of a wave peak-to-valley. It was perfect, needing no additional work. * My serendipitous mirror story quickly made the rounds of telescope makers, but it only reinforced my desire to own an equally crafted Questar. After all, my F/7 Newtonian reflector with a (Michael) Spacek, German equatorial mount would not fit into my compact, 95 horsepower, Corvair automobile. Spacek had a robust optical shop in Pottstown, PA, where he manufactured his own brand of telescopes. He also produced optics for the premier US planetarium manufacturer Spitz, Inc., of Chadds Ford, PA. * When I graduated from Kutztown University in May of 1972, my parents gave me a monetary gift of $400; both sets of grandparents each contributed an extra $100. I provided another $100 of my own funds and purchased a used Standard Model Questar with a quartz mirror, recommended to me by Paul Shenkle for its optical excellence. That telescope underwent modifications in subsequent years. It accompanied my friend, Allen Seltzer, and me as we discovered America's national parks. However, my fondest recollection of viewing through this Questar was not an astronomical observation. From about three miles away, Allen and I watched a group of roped mountain climbers traversing an ice field as they attempted to scale the Grand Teton in Grand Teton National Park, Wyoming! I'm still the proud custodian of that Questar, and more importantly, the wonderful memories it produced during my lifelong journey in astronomy. Ad Astra!
1554 MAY 31, 2026: May's Blue Moon: May's concluding moon on the 31st is colored blue. Luna was last full (Flower Moon) on May 1. Astronomically, most people associate the second full moon of a month with the blue moon, and the motto "once in a blue moon" still holds true. Blue moons do not occur that often, approximately once every 2.7 years. However, the definition was not always that way. * The evolution of the blue moon began with The Maine Farmers' Almanac which was published between 1819 and 1968. From 1932 to 1957, the book used a seasonal scheme to determine when a blue moon would occur. Their blue moon formula followed the time between the solstices and the equinoxes, which occur around the date of the 21st of March, June, September, and December. Moon names in The Maine Farmers' Almanac were aligned with indigenous and Colonial American names, as well as the ecclesiastical Easter calendar. Simply put, a full moon with a particular name had to occur at the same time of the year. When there were four full moons in a season, the calendrical sequence of moons was thrown out of order because the fourth moon in that sequence would occur too early. Throughout many blue moon cycles, the moon names would cycle backward against the calendar, occurring earlier and earlier. To correct for this and keep the moon names concurrent with the time of the year, The Maine Farmers' Almanac called the moon blue when the third full moon in a four full moon seasonal cycle occurred. * Our modern definition of a blue moon, two full moons occurring within a calendar month, stemmed from a misunderstanding of The Maine Farmers' Almanac's rule. The misinterpretation changed the third full moon in a four full moon season to any month that contained two full moons. The error was first published in a 1946 article in Sky and Telescope Magazine. * Deborah Byrd, creator of the National Public Radio's EarthSky program (https://earthsky.org/) popularized the new term by hyping the mistake contained in the 1946 S&T piece in her January 31, 1980 episode. During the next two decades, the new definition gained traction from Byrd's EarthSky presentation. It was cemented into the lexicon by the publicity surrounding the blue moon on January 31, 1999. The older meaning also continued to be used which added to the confusion. * My fascination with the new definition occurred when I wanted to write a StarWatch article about blue moons many decades ago. I realized that I had never seen a written explanation of the term and wanted more clarity. Thinking it was a well-established concept, I went to the lunar section of my astronomical library and eventually thumbed my way through the indexes of about 70 books without finding a single definition. There was not any reference to a blue moon as the second full moon of a month, including the third full moon in a four full moon seasonal cycle. There was, however, one notation about a moon that appeared visually blue after a volcanic eruption. The blue hue of the moon was created by extremely fine volcanic dust scattering reflected sunlight. Wondering about the correctness of what I had been teaching my students during the past 25 years, I scrubbed the article until I could find more details. I was not alone in my concern about the new definition because at the same time serendipitously, Sky & Telescope magazine broached the same subject, admitting their error and providing the historical evolution of how the two moons in a month definition came into existence. Just in case you're wondering, my next article about the blue moon is scheduled for Sunday, December 31, 2028. Yes, you've got it; there is a blue moon occurring in that month. Happy May Blue Moon. Ad Astra!