StarWatch: Moravian University Astronomy

SEPTEMBER 2025

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1516 SEPTEMBER 7, 2025: Eclipse Chasers: We've Come A Long Way: Even if you are not a regular reader of this column, you know that I like eclipses of any kind, but particularly total solar eclipses. They present significant challenges for maintaining composure during the brief span of minutes, sometimes seconds, when observers are plunged into the shadow of the moon. Those precious moments require a balance between visual observations and photographic pursuits. I doubt if I will ever achieve that equilibrium, since I enjoy capturing the moment digitally. * In April 2023, I was at the Parkes Radio Observatory in New South Wales, Australia, when I came across Eclipse Chasers by Nick Lomb and Toner Stevenson, printed by CSIRO Publishing, Melbourne, 2023. There are aspects of the book the authors could have improved. These include better maps and drawings, a more straightforward explanation for the repetition of eclipses, a better in-depth treatment of observing techniques, and a more thorough investigation of how First Nation inhabitants (Aborigines) could have understood how to predict solar eclipses, given that these cultures had no written form of communication. * Where Eclipse Chasers does shine, however, is in the meticulous descriptions of nineteenth and early twentieth-century attempts to view total solar eclipses from Australia and its environs. This included the discovery and colorizing of many photographic images. Bad weather on eclipse day prevented Australian scientists from gathering significant information about the astrophysics of the sun from 1857 to 1911. These expeditions to record the five total solar eclipses that occurred during this period involved enormous efforts and logistical planning on the part of astronomers and their staffs to reach the desired locations. Acquiring tons of scientific instrumentation from primarily England, then safely, along with supplies, transporting everything to the eclipse site, setting up telescopes and cameras, learning how to use the gear, and practicing for totality, proved herculean in efforts. Then it rained or was mostly cloudy on eclipse day. The doom and gloom record for Australian eclipses was finally broken on September 21, 1922, with a TSE that swept across a cloud-free continent coast-to-coast. * Transportation by road was almost nonexistent until the 1922 eclipse, and cars and trucks did not become the dominant mode of transportation in Australia until the late 20th century. I witnessed this in 2000, when a 466-kilometer (290-mile) road trip from Sydney to Siding Spring Observatory took 10 hours. Currently it takes about six hours Transportation to the centerline for all earlier eclipses, except the Sydney 1857 TSE, occurred via ship, which necessitated observing near the ocean where cloudiness was substantially more likely. * The Adelaide Observatory in South Australia provided the best example of the difficulties of overland transportation for the 1922 Einstein eclipse. The goal was to retest the General Theory of Relativity by noting how a massive object like the sun deflected the positions of stars near the sun during totality. * First, the observatory director, George Dodwell, travelled to England to secure the necessary equipment and discuss how the observations were to be acquired. Some of the gear came from the U.S., a camera and two lenses from the Allegheny Observatory in Pittsburgh and an equatorial mount to drive the camera from Lick Observatory near San Francisco. Once gathered, the equipment departed Adelaide via horse and cart, reaching the train station for a 650-kilometer overland journey to the end of the Great Northern Railroad at Farina, now a ghost town in South Australia. From there a small team of camel drivers with 31 dromedaries (one hump), transported everything another 645 kilometers across the harsh central desert region of Australia to a sheep station named Cordillo Downs. That journey took 50 days. Photos are here. As I read this, I did not consider that each night the equipment had to be off loaded from the camels and reloaded in the morning for the next leg of the journey. * Under perfect weather conditions, the efforts successfully provided an independent test that verified Einstein's predictions. This happened after Dodwell returned to Cordillo Downs six months later via motorcar to record the same stars, at the same altitude at night that were near to the sun during the eclipse. * So should a person be considered an eclipse chaser who has given his thousand-dollar deposit to Insight Cruises to rendezvous with the August 12, 2026 total solar eclipse in the Mediterranean? The 14-day cruise visits eight ports of call, including Lisbon, Barcelona, Rome, and Athens. * The advertising slogan for Virginia Slims cigarettes, introduced in 1968, targeted mainly at women, probably says it best. "You've come a long way, baby!" And so have we all. Ad Astra!

1517

SEPTEMBER 14, 2025: Keen-Eyed Russel

I have a small meteorite collection that I have built over 40 years, collecting specimens here and there when extra cash was at hand. They are a good investment, but they most often lack the personalities and presentation that minerals possess. Most are rather dull-looking. I have frequently professed, "Look for the ugliest booth if you are at a rock and mineral show. It will undoubtedly be a vendor who is selling meteorites." * What makes these rocks from outer space so fascinating to me? They are all about 4.5 billion years old, older than the oldest material that any geologist can find on Earth. Zircon crystals discovered in Western Australia have been dated to 4.4 billion years. Meteorites represent the oldest material that anyone can find in our solar system. * Holding a meteorite in your hand is like having a time capsule from the distant past, from the very beginning of the solar system's geologic history. In addition, the meteorite has been orbiting the sun for virtually all of its existence, because once on the ground, Earth's weathering processes, both chemical and physical, can easily render them unrecognizable in a matter of years, depending upon the location and composition of the meteorite. * My wife and I were recently at Bey's Rock Shop, 615 PA 100 in Bechtelsville. Jeannie and Jim Bey own the store. In business since 1961, daughter Kelly Boyer, her husband Matthew, and their almost 13-year-old son, Russel, assist the Beys. Although Russel, with his short, cropped hair, looks like any typical kid on the doorstep of maturing, engaging him in conversation finds that his knowledge base is well ahead of many adults. He enjoys reading, cooking, gardening, and a whole host of other atypical activities that a person of his age would find distasteful. I have never seen a smartphone in his possession. Because of his interests, Russel is in charge of Bey's fossil collection. * Fossilized (petrified) wood also interests me. Just like a meteorite, when I hold a section of a tree or fern in my hand that was alive 80 or 300 million years ago, it simply blows my mind. The difference, however, is that petrified wood can often be exquisitely beautiful, carrying most of the hues of the rainbow, including bark and the delicate markings of tree rings frozen into its silicate matrix that slowly replaced the organic material of the tree. * After resisting the temptation of a Megalodon tooth that Russel had shown me, Jim Bey called me over to identify three meteorites that most likely were discovered in the mid-twentieth century. Russel followed along. * I examined them. Two were highly oxidized (rusted), but the third, a nice 802-gram specimen, looked like it had weathered captivity fairly well. All three were iron-nickel; and 70 or 80 years ago, the most prevalent meteorites in the hands of a private collector were from Meteor Crater near Winslow, Arizona. That was just a wild guess that I kept to myself. I gave the iron to Russel, who started manipulating it and exclaimed, "Oh, there's some writing." I had missed that critical find. Jim gave me a loop and I was able to discern two lines of a hand etching, CD L4, followed below by HN 1948. See a photo here. It was not immediate, but after a while, it all jived. The CD stood for Canyon Diablo, the official name of the meteorite associated with Meteor Crater; the HN for Harvey Nininger, often called the father of meteoritics, and 1948, most likely the year that Nininger found the specimen. In 1948, Nininger, along with his family, operated the American Meteorite Museum (1942-1953) on old Route 66, located about 5.5 miles from the crater. To support his livelihood, meteorite hunting and selling were part of his routine. I'm assuming the L4 represented a grid system to locate the meteorite's position, but I have not been able to confirm this datum. Ironically, my grandparents, Arthur and Marie Becker, had visited the museum in 1947 or 1948 on an extended road trip to the western US. My grandmother recalled a short but expressive individual, certainly Nininger, welcoming another meteorite enthusiast into his exhibit room. * Russel then discovered another etching that had escaped my attention, 1# 13. If the mass of the meteorite, 802.4 grams, is converted into the weight of the iron in pounds and ounces, the calculation reveals one pound, 12.3 ounces, close to the inscription. It all seemed to fit fairly well. Thank you, keen-eyed Russel; you are definitely going places in this world, and thank you Jim Bey for releasing the Nininger meteorite into my custody. Ad Astra!

Almost thirteen-year-old Russell Boyer of Bey's Rock Shop in Barto, PA found the key to deciphering the who, where, and when about this meteorite. Read the article to discover the details. Photo by Gary A. Becker...

Russel Boyer, still trying to sell me that Megalodon tooth... Photo by Kelly Boyer...

The view from my bathroom window was spectacular on September 19 with the moon, Venus, and the alpha star of Leo the Lion, Regulus, gleaming in the clear, dawn sky. Venus was just over 1/3rd degree from the moon's limb. Photo by Gary A. Becker...

1518 SEPTEMBER 21, 2025: Back to Fall: Even though it may not quite feel like autumn, the sun is once again poised to cross the celestial equator in its downward slide towards its low point in the heavens. That will happen on the winter solstice, December 21. The first moment of fall will occur on September 22 at 2:19 p.m., EDT. September 22 may come as a surprise to many individuals since most students learn the seasons seem to "switch" on the 21st of the designated month: March, June, September, and December. Because the dates of seasonal changes fluctuate, that is how I frame it with my students. Each year, these dates and times vary slightly because a calendar year, 365 days, is nearly a quarter day shorter than the period of one year (Tropical Year)! In addition, because we orbit the sun in an ellipse, our planet's speed is constantly changing, fastest when closest to the sun and slowest when farthest. If Earth's orbit around Sol were circular, then our speed would be constant with each season having 91 days, 6 hours based upon a 365-day year. I was curious to see how the dates of the seasonal changes would be influenced due to the shortness of February, which has 28 or 29 days, and July, followed by August, both having 31 days. * I completed a series of arithmetical calculations to show the differences adding 91 days, 6 hours to my starting date of the 2026 winter solstice, which I arbitrarily set for convenience at 12:01 a.m., December 21. The results can be view in the accompanying list. I carried the sequence through one leap year, ending on the vernal equinox of 2031.
Winter Solstice: December 21, 2026, 12:01 a.m.
Vernal Equinox: March 22, 2027, 6:01 a.m.
Summer Solstice: June 21, 2027, 12:01 p.m. Autumnal Equinox: September 20, 2027, 6:01 p.m.
Winter Solstice: December 21, 2027 at 12:01 a.m.
Leap Year: Add an extra day to February (92.25 days total)
Vernal Equinox: March 21, 2028 at 6:01 a.m.
Summer Solstice: June 20, 2028, 12:01 p.m.
Autumnal Equinox: Sept. 19, 2028, 6:01 p.m
Winter Solstice: December 20, 2028 at 12:01 a.m.
Vernal Equinox: March 21, 2029 at 6:01 a.m.
Summer Solstice: June 20, 2029, 12:01 p.m.
Autumnal Equinox: September 19, 2029, 6:01 p.m.
Winter Solstice: December 20, 2029 at 12:01 a.m.
Vernal Equinox: March 21, 2030 at 6:01 a.m.
Summer Solstice: June 20, 2030, 12:01 p.m.
Autumnal Equinox: September 19, 2030, 6:01 p.m.
Winter Solstice: December 20, 2030, 12:01 a.m.
Vernal Equinox: March 21, 2031, 6:01 a.m.
Since we are revolving around the sun in an elliptical orbit with our greatest distance from the sun occurring in early July, it is at this time of the year that Earth is moving slowest in its orbit. Spring to autumn, when we are traveling more slowly in our orbit, is lengthened by an extra six days than the time between autumn and spring, when we are moving faster in our orbit around the sun. To compensate for this difference, we have a shorter February, but that still does not make up for the longer time interval between spring and autumn. To help to add this extra time, the first moment of spring, when the sun crosses the equator from south to north, typically occurs on March 20. The autumnal equinox, when the sun crosses the equator from north to south, generally happens on the 22nd or 23rd of September. Additionally, July and August both have 31 days, completing the extra time needed for the slower-moving Earth to bring the sun back to the equator for the autumnal equinox. Ad Astra!

1519 SEPTEMBER 28, 2025: Motion: The Next Great Leap for Astronomy: Nestled on the summit of the 8,800-foot Peñón peak of the Cerro Pachón Mountains in central Chile sits the Vera C. Rubin Observatory, poised to create the next great leap in astronomical information acquisition. The 8.4-meter (27.6-foot) in diameter primary mirror has been designed to be virtually distortion-free, but that is not its greatest asset. The telescope possesses an ultrafast focal ratio of F/1.2, allowing it to capture a 9.6 square degree chunk of sky in just 30 seconds using the world's largest digital camera, possessing a 3.2 gigapixel sensor. In just five seconds, the 600-ton telescope will reposition to take its subsequent exposure, producing about 20 terabytes of data every night. Compare that to the Hubble Space Telescope, which has collected about eight terabytes of data yearly, and the James Webb Space Telescope, which has collected about 200 terabytes annually. Rubin will photograph the entire sky visible from 30 degrees south latitude every three nights. The first trial image assembled in just seven nights boasted over 10 million galaxies, most of them never seen before, and the discovery of 2100 new asteroids. This first image was the compilation of 1200 individual exposures. * Up to the present time, astronomers have studied the universe using still images, snapshots of the cosmos. Rubin's ultimate goal will be to create a digital time-lapse movie of the universe over 10 years. With software designed to subtract anything stationary or non-variable from the photo, only transient objects will remain, revealing everything that changes in the visible universe. These include variable stars, amalgamating neutron (dead) stars and black holes, young protostars beginning nucleosynthesis, and most importantly, rare supernovae, massive dying stars that suffer core collapse and produce titanic explosions. Rubin may finally answer the ultimate fate of our universe. * From the study of Type 1a supernovae investigated by the Hubble Space Telescope, astronomers were able to begin their understanding that our universe is accelerating. This type of supernova occurs in a binary system when a bloated red giant near the end of its life pours hydrogen and helium onto a companion white dwarf, eventually causing the dwarf to supernova. Type 1a events produce a precise light output that allows astronomers to compare their actual (absolute) brightness with their observed (apparent) brightness, and thus obtain the most accurate distance measurements for the universe. In total, over 16,000 supernovae events have been witnessed throughout the entire history of astronomical observations. Rubin is expected to image 100,000 stellar explosions each year. A better understanding of the acceleration of the universe will allow astronomers to quantify more accurately the total amount of dark energy that is driving the expansion. * American astrophysicist Vera Florence Cooper Rubin (1928-2016), for whom the observatory was named, was a pioneer in the study of dark matter and its effects on the rotation of galaxies. In a Keplerian environment like our solar system, the closer a planet is to the sun, the faster its orbital speed. In the center of a galaxy where stellar densities are at their greatest, it is just the opposite. Orbital velocities increase with distance because stars near the center feel the gravitational tugs of stars farther away. This increases their speeds. It would be expected that stars much farther from the galactic nucleus, similar to our sun, would begin to feel the galaxy's center somewhat like a point source and behave in a more Keplerian fashion, but that is not the case. The outer regions of a galaxy rotate more like a disk, with velocities slowly increasing with distance from the center. The conclusion that Rubin forged is that an undetectable mass that possesses gravity, dark matter, must lie beyond the galaxy's unseen structure. * These are just some of the anticipated discoveries and refinements that will undoubtedly shake up the astronomical landscape and lead to a much better understanding of the universe in which we live. I can't wait. Ad Astra!