StarWatch: Moravian University Astronomy

FEBRUARY 2024

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

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lunar phases

1433 FEBRUARY 4, 2024: Capturing the April 8th Eclipse: The audience of eclipse chasers who had successfully witnessed the Australian hybrid eclipse broke into an enthusiastic round of applause and cheers when Kelly Beatty from Sky and Telescope said the best way to see your first total solar eclipse is simply to watch. * I admit I have spent too many precious moments in the moon's shadow, fixated on the electronic screen of my camera. Still, anyone who makes an effort to see a total solar eclipse should try to record the happening because there is nothing like sharing your experiences with friends if it's your photography. * Because of the longer duration of totality, about four minutes, it should be possible to record the event digitally and have ample time to view the corona and surrounding regions visually. That does not mean using a high-tech digital camera. Most smartphones can record images or video in low-light conditions, which is precisely what will happen as the moon sweeps into totality. I suggest purchasing a device that attaches your smartphone to a small tripod. I acquired an Ulanzi ST-27 Metal Phone Tripod Clip 2476 for the Oz Eclipse for $29.95. You can get holders much cheaper, but I wanted one that would adapt to my larger Pixel 7 Pro and could be fully rotated into any position. For Australia, I set the phone camera for time-lapse, one frame every 10 seconds, and off it went, doing its thing for about 90 minutes, allowing me to devote all my attention to acquiring images with my Canon 80D camera. * The time-lapse proved interesting, with people scurrying around the deck of the ship like ants, stopping abruptly to look, but basically paying little attention to the eclipse until only a few minutes before totality and then resuming the same activity after totality had passed. * Peter Detterline and I recorded the eclipse from first contact until the moon slipped from the sun. No one near us did the same. Also, we could find no one practicing their shipboard photographic techniques before E-day. Pete and I experimented extensively before we flew to Australia and several hours on the Pacific Explorer to reestablish the methods that had brought us success in previous eclipse trips. You have got to put in the practice time if you want the results, and that is still no guarantee of success. * If you want to rehearse with your smartphone in eclipse-like lighting conditions, try going out of doors on a clear evening about 30-40 minutes after sundown. Set your phone to 1x, not wide field (0.5x), for a much higher image quality. I would only use smartphones to capture the big picture, which includes the reaction of the people observing with you. Smartphones normally have focus issues at higher magnifications. * To increase the visual viewing time during totality, consider setting your DSLR camera to take multiple images each second automatically. I did that in Australia to capture the ingress diamond ring that had always eluded me. I'm embarrassed to admit that I was still so engrossed with the camera that I failed to look up. That was my tenth central eclipse, so if the April 8 event is your first, be prepared to become overwhelmed by the heavenly light show. * Interested in getting tips on capturing the eclipse, whether seen as a partial event or within the path of totality? An excellent article can be found here, while a video created by Alan Dyer, a noted Canadian astrophotographer, can be found at this link. Much success as you prepare for the big one on April 8. Ad Astra!

1434

FEBRUARY 11, 2024: Eclipse Observing on the Cheap

There is no question that I'm a little more excited about the April 8 total solar eclipse than most individuals. However, I will feel successful if I can give eclipse fever to a few other enthusiasts and convince them to see totality. For most observers, staying grounded in one location will be the reality because of jobs, interest, and other commitments so that the eclipse will be a partial event with little in the way of darkening, no shadow bands or diamond ring, no Bailey's Beads, and no spectacular corona girding the moon. * The continental US will see its next total eclipse of the sun on August 24, 2044; a near sunset event will be visible from Montana and North Dakota. The sun will set eclipsed in eastern North Dakota. The follow year on August 12, there will be a coast-to-coast—northern California to Florida spectacular with totality lasting at maximum duration, 6 minutes, 6 seconds just off the eastern coast of Florida. There is time to regroup for many of us, but it is still a long wait. * One of the best ways to include children in the eclipse hoopla while also keeping them safe from eye damage is to have them construct a pinhole solar projection box. Take a cardboard box and cut a square at one end. Over the hole, attach a sheet of aluminum foil perforated with one or several pinholes. On the opposite end, attach a white sheet of paper to act as a projection screen for the pinholes. The unit will produce a relatively sharp solar image and easily show the eclipse's progression. The ideal hole size to box length is 1:400. A pinhole is about 1 millimeter in diameter. Therefore, the perfect box length should be 400mm or about 16 inches. Cut a rectangular opening near the screen so that your child's eyes can peek into the box and see the projection of the sun onto the white screen. Avoid making your projection unit from a tube because the length of the tube to the small area onto which the sun will be projected makes finding Sol and keeping it on the screen difficult for kids. Viewing the eclipse this way will keep your child's back to the sun while the eclipse is in progress. * You can also place a white sheet on the ground and crisscross your fingers, allowing the sunlight to shine through the holes between fingers to produce images of the eclipsed sun. A colander about three feet above the ground will project vivid images on a white ground sheet. Ritz crackers positioned near a sheet of white paper will also work. Just don't eat the Ritz, and of course never view the sun directly without the proper filters. See the photos below to see more suggestions to watch this eclipse on the cheap. Ad Astra!

The diameter of the pinhole to the screen distance, ideally should be 1:400. A normal pinhole creates a distance of approximately 16 inches for the screen location. Brewer, Bryan, Eclipse, Earth View, Inc., Seattle, WA, 1970, p.82...

Gary A. Becker images...

Note the eclipses being created at the base of the fingers. Gary A. Becker image...

Gary A. Becker, Adam R. Jones (insert), Internet (colandar, thermometer) images...

Colander head, Pete Detterline. Dean Bauer image...

1435 FEBRUARY 18, 2024: Solar Snap the April 8 Eclipse: The digital revolution in smartphone technology continues to amaze me to the point where I use my Google Pixel 7 Pro more and more often. It's not because I am becoming lazy either. Its ability to produce vivid colors with an incredible amount of dynamic range that captures details in shadowed areas and regions of high contrast, as well as its low light capabilities, make it the preferable choice. The top end Galaxy 22/23 and the iPhone 13-15 are major competitors with the Google 7/8 Pro. They are all incredible devices. I will still use my Canon 80D (Digital Single Lens Reflex) camera for higher magnification/resolution pictures from my telescope. Still, I am confident that my Pixel Pro will also be engaged in automatically taking other images of the event. * For most enthusiasts who do not own a DSLR camera and take pictures exclusively with a smartphone, I'd like to introduce you to an application called Solar Snap. When I read the advertisement for this product, the marketing package came with two large solar filters, including Velcro for attachment to two phones, and two pairs of eclipse glasses. Prices on Amazon ranged from $15.00 to $23.95, not including postage and handling. The advertisement on the packaging said that the Solar Snap app was free, so I downloaded it on the Play Store. I had plenty of safe solar viewing material in the form of solar glasses from previous eclipse adventures and even larger solar viewers to tape over my camera phone lenses so that I could record images safely. * I answered several questions when I opened the app, allowing my phone camera to sync with the application and my location. I also promised never to be ignorant enough to view the sun without the use of proper filters. Having passed those tests, I finally got a look at the Solar Snap application. Zoom (magnification), exposure, and focus were neatly displayed upfront on moveable, orange toggle bars. There was no hunting for anything. The focus bar had a locking mechanism that ensured the image would be kept sharp. I could also focus the standard way by tapping on the screen, as well as recording a single image by tapping on a circle just like in regular camera mode. * However, two time-lapse increments were also available. A boxed "1" would take a single image every 10 seconds for the eclipse's partial phases. Taping on the box again revealed a "3," resetting the time-lapse to three images every 10 seconds for the diamond ring and totality. Solar Snap seemed to have the necessary functionality for a time-crunched event like a total solar eclipse. * If Solar Snap piques your interest, I recommend purchasing a device that attaches your smartphone to a small tripod. I acquired an Ulanzi ST-27 Metal Phone Tripod Clip 2476 for my Australian eclipse adventure this past April. The cost was $29.95. Phone holders can be acquired for much less money, but I wanted one that would adapt to my larger Pixel 7 Pro and could be fully rotated into any position. * If you are planning to record a video of the lighting conditions during totality (the big picture), including the reaction of friends, try imaging normally without Solar Snap and use a 1x magnification. I do not recommend recording stills or video at 0.5x (ultra-wide field) because the picture quality is much poorer. Totality like lighting conditions occur on a clear evening about 30-40 minutes after sundown so there are plenty of opportunities to test your smartphone. * In my StarWatch article of February 4, I only advised using your smartphone to capture the big picture. However, with Solar Snap, another choice has become available, capturing all aspects of the sun in eclipse. * One other word of advice, however—PRACTICE! E-day will be no time to learn new tricks. Photos are below. Ad Astra!

1436 FEBRUARY 25, 2024: Leap Year and the Calendar: When Julius Caesar was wooing Cleopatra in Egypt, he was introduced to the astronomer, Sosigenes of Alexandria, who may or may not have accompanied the couple back to Rome. Sosigenes consulted with Caesar to create a solar calendar which Julius proposed in 46 BC to replace the much-abused Roman lunar calendar. Rome adopted the Julian calendar on January 1, 45 BC after a 445-day long year to bring the calendar into step with the sun and seasons. * The year was based upon two successive passages of the vernal equinox by the sun, something that today is called the tropical year. Sol passing the vernal equinox first marked the moment of spring, a period of 365.25 days according to Sosigenes' plan. * Since calendars needed to be created with a whole number of days, the Earth would fall behind by one-quarter day each year until a whole day was accumulated after a four-year interval. An additional day was added to the shortest month of the year, February, to bring the sun into step with the vernal equinox. * There were two issues with Sosigenes' 365.25-day tropical year. The tropical year's duration was not the interval of time it took the Earth to orbit the sun because the vernal equinox was not a stationary target, but moved westward each year due to the 25,772-year precession cycle or wobble of the Earth's axis. The actual revolution of the Earth around the sun, known as the sidereal year, was 20 minutes, 24.5 seconds longer than our modern tropical year. Using the tropical year, however, was a good idea because it kept all holidays with fixed dates happening at the same time of the year with respect to the seasons. The other factor, however, was important with regards to keeping a consistent, repetitive calendar with celebrations such as Easter that had variable dates. The Julian 365.2500-day tropical year was 0.00781 day or a little over 11 minutes too long. This 1/128th day of extra time created a backward slide of the dates of the vernal equinox against the calendar and the earlier occurrences of Easter, a variable date, which was slowly moving toward the fixed date of Christmas. The Church understood the situation. If given enough time, Advent would overlap the time of Lent, and things might get a little confusing in the Church's liturgy. * The solution was the introduction of the Gregorian calendar under the leadership of Pope Gregory XIII in October of 1582, reducing the tropical year to 365.24250 days and bringing the calendar to an accuracy of one day in 3236 years. The modern tropical year is 365.24219 days, a difference of about 27 seconds. The ingenious manner in which this accomplishment occurred was to make century years leap years only if they were divisible by 400 without a fractional remainder. Thus, 1600 and 2000 were leap years, but the century years of 1700, 1800, and 1900 were not. To correct for the westward drift of the vernal equinox, October 4, 1582, was followed by October 15, 1582. The Gregorian calendar ensured that holidays like Christmas with a fixed date would remain immovable with the seasons and that Easter and Christmas would forever never "collide." * What does not remain fixed are the constellations. They will gradually shift backward against the year's dates due to the westward movement of the vernal equinox. Eventually, we will still be celebrating the 4th of July in the summertime, but with the current winter constellations visible in this forthcoming nighttime sky. Not to worry, that's about 12,000 years into the future when global warming and nationalism will be things of the past, and we will know that life is abundant in this universe. Topical discussions among historians will center on the early wisdom of humanity and how we successfully or luckily navigated through these tempestuous times. Ad Astra!