Category: Skywatching

Greetings, fellow SkyWatchers! If we can keep the clouds and rain away, this will be an incredible weekend to enjoy some peaceful and relaxing time under the Moon and stars. We’ll begin with a heads up on a partial lunar eclipse whose beginning – or end – will be visible to most of us. Check your times carefully, because this one crosses the international date line! While you’re out, take a look at the lunar surface for some very interesting craters – or just relax with binoculars and suck in the photons of some curious variable stars. Are you ready? Then I’ll see you in the back yard…

June 25, 2010 – Today celebrates the birth of Hermann Oberth. Born in 1894 on this date, Oberth is considered to be the father of modern rocketry and space travel. But you won’t need a rocket to travel skyward as we gear up for the 2010 partial lunar eclipse!

A major section of western North and South America is in for treat as they will be able to see the beginning stages. These areas include Western Brazil, western Venezuela, and South American countries west of these locations. Believe it or not, a section of the southeastern United States will even be able to witness the eclipse – if it’s not raining!

The dividing line runs through the state of Georgia following a diagonal path north to Minnesota. States west of this line will also be within range of seeing the entire event until sunrise. On the west coast of the United States, the Moon will slide into umbral eclipse at 3:16 a.m. PDT, be deepest in shadow at 4:38 a.m. PDT, and the eclipse ends at 6:00 a.m. PDT – right about dawn. Locations that will be able to see the entire partial eclipse include the Pacific islands such as Hawaii, Polynesia, Fiji, Marshall Islands, New Zealand, Papua New Guinea, Australia, and most of Japan and the Philippines. Regions such as eastern China, the east edge of the USSR, Indonesia and the Thailand area will be able to see the very end of the 2010 partial lunar eclipse.

Despite bright skies tonight, take out your binoculars and look for a circlet of seven stars that reside about halfway between orange Arcturus and brilliant blue-white Vega. This quiet constellation is named Corona Borealis, or the Northern Crown.

Just northwest of its brightest star is a huge concentration of over 400 galaxies that reside over a billion light-years away from us. Known as Abell 4065, the Corona Borealis Galaxy Cluster is an area so small in apparent size that from our point of view we could eclipse it with a small coin held at arm’s length!

June 26, 2010 – Happy Birthday, Charles Messier! Born in 1730 on this date, almost everyone recognizes the name of this French astronomer who discovered 15 comets. He was the first to compile a systematic catalog – the ‘‘M objects.’’ The Messier Catalogue (1784) contains 103 star clusters, nebulae, and galaxies. But did you know Lyman Spitzer, Jr, shared this birthday? Born in 1914, Spitzer advanced our knowledge of physical processes in interstellar space and pioneered efforts to harness nuclear fusion as a clean energy source. He studied star-forming regions and suggested that the brightest stars in spiral galaxies formed recently. Not only that, but Spitzer was the first person to propose placing a large telescope in space, and so launched the development of the Hubble Space Telescope!

Tonight the mighty Moon will still rule the sky, providing a wonderful opportunity for casual inspection. Why not grab a telescope and view the lunar surface for a couple of telescopic challenges that are easy to catch? All you have to know is Mare Crisium!

On the southeastern shoreline is a peninsula that reaches into Crisium’s dark basin. This is Promontorium Agarum. On the western shore, bright Proclus lights the banks, but look into the interior for the two dark pockmarks of Pierce to the north and Picard to the south. Be sure to mark them on your notes!

When you’re finished, point your binoculars or telescopes back toward Corona Borealis and about three finger-widths northwest of Alpha for variable star R (RA 15 48 35 Dec +28 09 24). This star is a total enigma. Discovered in 1795, most of the time R carries a magnitude near 6 but can drop to magnitude 14 in a matter of weeks – only to unexpectedly brighten again! It is believed that R emits a carbon cloud, which blocks its light. Oddly enough, scientists can’t even accurately determine the distance to this star! When studied at minimum, the light curve resembles a ‘‘reverse nova’’ and has a peculiar spectrum. It is very possible that this ancient Population II star has used all of its hydrogen fuel and is now fusing helium to form carbon.

July 27, 2010 – Tonight we’ll again honor the June 26 birth of Charles Messier by heading toward the lunar surface first, in order to pick off another study object on our list – the twin crater pair Messier and Messier A.

Located in Mare Fecunditatis about a third of its width from west to east, these two craters will be difficult to find in binoculars, but not hard for even a small telescope and intermediate power. Indeed named for the famed French astronomer, the easternmost crater is somewhat oval in shape, with dimensions of 9 by 11 kilometers. At high power, Messier A to the west appears to have overlapped a smaller crater during its formation; and it is slightly larger at 11 by 13 kilometers. Although it is not on the challenge list, you’ll find another point of interest to the northwest. Rima Messier is a long surface crack, which runs diagonally across Mare Fecunditatis’s northwestern flank and reaches a length of 100 kilometers.

For variable star fans, let’s return to and focus our attention on S Coronae Borealis, located just west of Theta and the westernmost star in the constellation’s arc formation (RA 15 21 23 Dec +31 22 02). At magnitude 5.3, this long-term variable takes almost a year to go through its changes – usually far outshining the 7th magnitude star to its northeast – but will drop to a barely visible magnitude 14 at minimum. Compare it to the eclipsing binary U Coronae Borealis about a degree northwest. In slightly over 3 days, this Algol-type will range by a full magnitude as its companions draw together.

Until next week? Wishing you clear skies!

This article’s awesome illustrations are: Eclipse Chart courtesy of NASA, Abell 4065, R CorBor and S CorBor from Palomar Observatory, courtesy of Caltech, Lyman Spitzer historical image, Crisium in Decline courtesy of Shevill Mathers and Messier craters by Damien Peach. We thank you so much!

Greetings, fellow Stargazers! Have you been enjoying the rain? Then keep your eyes open for a “celestial shower” as meteoritic activity picks up over the next few nights, culminating in the peak of the Ophiuchid meteor Saturday night through Sunday morning. While you’re out relaxing, be sure to spare some time for lunacy and take a look some interesting features on the Moon. Need a test of your telescope’s resolving power? Then I “double dare” you to take on Gamma Virginis! Whenever you’re ready, I’ll see you in the back yard….

Friday, June 18, 2010 – Let’s begin the day by recognizing the 1799 birth on this date of William Lassell, telescope maker and discoverer of Triton (a moon of Neptune), and Ariel and Umbriel (satellites of Uranus). As often happens, great astronomers share birth dates, and this time it’s 187 years later for Allan Rex Sandage. A Bruce Medalist, Dr. Sandage is best known for his 1960 optical identification of a quasar, with his junior colleague, Thomas Matthews.

Our telescope lunar challenge tonight will be Hadley Rille. Find Mare Serenitatis and look for the break along its western shoreline that divides the Caucasus and Apennine mountain ranges. South of this break is the bright peak of Mons Hadley, which is of great interest for several reasons, so power up as much as possible.

Impressive Mons Hadley measures about 24 by 48 kilometers at its base and reaches up an incredible 4,572 meters. If volcanic activity had created it, Mons Hadley would be comparable to some of the very highest volcanically formed peaks on Earth, like Mount Shasta and Mount Rainer. South is the secondary peak, Mons Hadley Delta. It is home to the Apollo 15 landing site just a breath north of where it extends into the cove created by Palus Putredinus. Along this ridge line and smooth floor, look for a major fault line, winding its way across 120 kilometers of lunar surface; this is Hadley Rille. In places, the Rille spans 1,500 meters in width and drops to a depth of 300 meters below the surface. Believed to have been formed by volcanic activity 3.3 billion years ago, we can see the impact lower gravity has on this type of formation. Earthly lava channels are usually less than 10 kilometers long, and only around 100 meters wide. During the Apollo 15 mission, Hadley Rille was visited at a point where it was only 1.6 kilometers wide, still a considerable distance. Over a period of time, the Rille’s lava may have continued to flow through this area, yet it remains forever buried beneath years of regolith.

Saturday, June 19, 2010 – Tonight on the Moon we’ll be looking for another challenging feature and the craters that conjoin it—Stofler and Faraday. Located along the terminator to the south, crater Stofler was named for Dutch mathematician and astronomer Johan Stofler.

Consuming lunar landscape with an immense diameter of 126 kilometers, and dropping 2,760 meters below the surface, Stofler is a wonderland of small details in an eroded surrounding. Breaking its wall on the north is Fernelius, but sharing the southeastern boundary is Faraday. Named for English physicist and chemist Michael Faraday, this crater is more complex and deeper (4,090 meters) but far smaller in diameter (70 kilometers). Look for myriad smaller strikes that bind the two together!

When you’re done, let’s have a look at a delightful pair—Gamma Virginis (RA 12 41 41 Dec +01 26 54). Better knownas Porrima , this is one cool binary whose components are of almost equal spectral type and brightness. Discovered by Bradley and Pound in 1718, John Herschel was the first to predict this pair’s orbit in 1833, and stated that one day they would become inseparable to all but the very largest of telescopes—and he was right. In 1920 the A and B stars had reached their maximum separation, and during 2007 they were as close together as they ever can be. Observed as a single star in 1836 by William Herschel, its 171-year orbit puts Porrima in almost the same position now as it was when Sir William saw it!

Sunday, June 20, 2010 – In the predawn hours, we welcome the ‘‘shooting stars’’ as we pass through another portion of the Ophiuchid meteor stream. The radiant for this pass lies nearer Sagittarius, and the fall rate varies from 8 to 20 per hour, but the Ophiuchids can sometimes produce more than expected! Perhaps the sky acknowledges the 1966 passing of Georges Lemaitre on this date? Lemaitre researched cosmic rays and the three-body problem and in 1927 formulated the Big Bang theory using Einstein’s theories.

Are you ready to explore some more history? Then tonight have a look at the Moon and identify Alphonsus; it’s the centermost in a line of rings and looks much like the Theophilus, Cyrillus, and Catharina trio.

Alphonsus is a very old Class V crater, spans 118 kilometers in diameter, drops below the surface to about 2,730 meters, and contains a small central peak. Eugene Shoemaker had studied this partially flooded crater and found dark haloes on the floor. Again, this could be attributed to volcanism. Shoemaker believed they were maar volcanoes, and the haloes were dark ash. Power up and look closely at the central peak, for not only did Ranger 9 hard land just northeast, but this is the only area on the Moon where an astronomer has observed a change and backed up that observation with photographic proof.

On November 2, 1958, Nikolai Kozyrev long and arduous study of Alphonsus was about to be rewarded. Some two years earlier Dinsmore Alter had taken a series of photographs from the Mt. Wilson 60’’ reflector that showed hazy patches in this area that could not be accounted for. Night after night, Kozyrev continued to study at the Crimean Observatory, but with no success. During the process of guiding the scope for a spectrogram, the unbelievable happened—a cloud of gaseous molecules containing carbon had been captured! Selected as the last target for the Ranger series of photographic missions, Ranger 9 delivered 5,814 spectacular high-resolution images of this mysterious region before it crashed nearby. Capture it yourself tonight!

Until next time? Ask for the Moon… But keep on reaching for the stars!

This week’s awesome images are (in order of appearance): Dr. Alan Sandage courtesy of Dr. Sandage, Hadley Rille, courtesy of Wes Higgins, Stoffler and Faraday courtesy of Wes Higgins, Porrima – Palomar Observatory courtesy of Caltech, Georges Lemaitre and Albert Einstein (historical image), Ranger 9 Image of Alphonsus taken 3 minutes before impact courtesy of NASA, Alphonsus’ central peak taken 54 seconds before Ranger 9 impact courtesy of NASA. We thank you so much!

Greetings, fellow SkyWatchers! What better way to celebrate a snow-bound weekend than by having a look at the “Eskimo”! While we’re at it, we’ll take a look at an awesome open cluster suitable for all optics and take an adventure towards one of the best supernovae remnants in the night sky. Along the way, we’ll explore some of the history and mystery behind these objects, so dust off your optics and I’ll see you in the backyard….

Friday, February 12, 2010 – Today is unofficially Physicist’s Day! We’ll begin by celebrating three notable births on this date, starting in 1893 with Marcel Minnaert, solar physicist. Minnaert’s innovative techniques in solar spectrophotometry aided the discovery of structure in the Sun’s outer layers. Next is 1918 and Julian Schwinger, a physicist big on electromagnetic field theory, who shared the Nobel Prize for work in quantum electrodynamics. Last is the 1936 birth of Fang Lizhi, who published his work on the Big Bang theory in 1972. Even in exile from Communist China, he continues to express his belief in freedom of intellectual expression and continues his work in theoretical cosmology.

Tonight we’ll time-travel back 5,000 years as we head for NGC 2392. Located about two fingerwidths southeast of Delta Geminorum (RA 07 29 10 Dec +20 54 42), this beauty is a planetary nebula commonly known as the ‘‘Eskimo.’’ Discovered in 1787 by Sir William Herschel, a small telescope will see it as a fuzzy green star, while aperture will reveal definite annulus around its central stellar point. A steady night helps to reveal details, and a nebula filter lights it up! NGC 2392 is so complex that it is not yet fully understood. As with Minnaert’s solar work, we know the glowing gases are the outer layers of its central star, shed 10,000 years ago, while the inner ribbons of light (called filaments) are areas where particles are being pushed away by the strong stellar wind. Even now, we still can’t quite explain the unusual outer filaments! It won’t look like a Hubble image in your telescope, but you can still marvel at a unique mystery—seeing its light as it was when ‘‘physicists’’ began using the first ‘‘computer’’—the newly invented abacus!

February 13, 2010 – We salute Johan Ludvig Emil Dreyer, who was born on this date in 1852. At age 30, Danish astronomer Dreyer became director of the Armagh Observatory—not a grand honor, considering the observatory was so broke it couldn’t afford to replace its equipment. Like all good directors, Dreyer somehow managed to get a new 1000 refractor but no funds for an assistant to practice traditional astronomy. However, J.L.E. was dedicated and within 6 years had compiled all observations known to him into one unified work called the New General Catalogue of Nebulae and Clusters of Stars (NGC). Originally containing 7,840 objects, and supplemented in 1895 and 1908 with another 5,386 designations, the NGC remains the standard reference catalog. Although Dreyer’s personal observations included such nebulous descriptions as ‘‘a vault of stars,’’ modern astronomers continue to use his abbreviations as a kind of shorthand.

Honor Dreyer tonight by discovering one of his catalog objects suited for all optics—NGC2287. Located about two finger-widths south of Alpha Canis Majoris (RA 06 46 00 Dec +20 46 00), only an open cluster this bright could stand up against brilliant Sirius. From a dark-sky location, your unaided eye can even spot this magnitude 4.5 star vault as a hazy patch. Aristotle saw it as early as 325 BC! Officially discovered by Hodierna, we know it best by the designation Messier Object 41. Even from 2,300 light-years away, the cluster’s brightest star, an orange giant, stands out clearly from the stellar nest. With large aperture, you’ll notice other K-type stars, all very similar to Sol. Although small scopes and binoculars won’t reveal too much color, you might pick up on the blue signature of young, hot stars. NGC 2287 could be anywhere from 190 to 240 million years old, but its stars shine as brightly now as they did in Aristotle’s day. . .and Dreyer’s!

February 14, 2010 – On this date in 1747, astronomer James Bradley presented his evidence of Earth’s wobble, called nutation. The study took 19 years, but won Bradley the Copley Medal! In 1827, George Clark was born. The name might not ring a bell, but it was indeed a bell—melted down—that he used to create his first brass telescope. George’s family went on to produce the finest—and largest—telescopes of their time. In 1898 one of my personal heroes, Fritz Zwicky came along, his name synonymous with the theory of supernovae. The Swiss-born Caltech professor was also a salty character, often intimidating his colleague Walter Baade and referring to others as ‘‘spherical bastards.’’ Although Zwicky was reportedly difficult to work with (geez… wonder why?), he was also brilliant—predicting the phenomenon of gravitational lensing. An unsung genius!

Tonight we’ll look at a supernova remnant as we venture to the Crab Nebula. Finding M1 is easy: it can be seen with as little as 7x magnification. Locate Zeta Tauri (about halfway between Orion’s ‘‘head’’ and the southernmost bright star in Auriga) and aim about 1 degree northwest (RA 05 34 31 Dec +22 00 52). Viewing M1 with small optics helps to understand why Charles Messier decided to compile his famous catalog. Unaware of its earlier discovery, Messier located a fuzzy object near the ecliptic and assumed it was the return of Halley’s Comet. Considering his primitive telescope, we can’t fault his observation. But Chuck was a good astronomer. When he realized the object wasn’t in motion, he began compiling a log of things not to be confused with comets—the famous Messier objects. Enjoy looking at this spectacular deep-sky jewel, and we’ll study it in depth another time. Of course, Zwicky may have cursed me for saying that observing without science is an ‘‘empty brain exercise and therefore a waste of time.’’ But on the date of his birth, I took his advice. . . ‘‘Give me a topic and I’ll give you an idea!’’

Until next week? Dreams really do come true when you keep on reaching for the stars!

This week’s awesome stellar images are from Palomar Observatory, courtesy of Caltech. We thank you so much!