November 11 Membership Meeting: “Catching the Sun…”

In its prime, the McMath-Hulbert Observatory shone in the sun, circa 1941. Credit: University of Michigan and McMath-Hulbert Observatory

The final Membership Meeting of the Cuyahoga Astronomical Association (CAA) for 2019 will take place Monday, November 11. The meeting will feature a presentation by member Steve Gallant entitled, “Catching the Sun: Robert McMath and the McMath-Hulbert Solar Observatory.”

Located north of Pontiac, Michigan and opened in 1929, after the initial attempts to study the moon, the main preoccupation of the observatory was the sun. McMath-Hulbert was once the second largest solar observatory in the world. Spears will fill us in on the observatory’s history and the current efforts to preserve and promote its continued use!

The CAA’s monthly meetings are held on the second Monday of every month except December at 7:30 p.m. in the Rocky River Nature Center; 24000 Valley Parkway; North Olmsted, Ohio, in the Cleveland Metroparks. Meeting programs are open to the public. Following the presentation and a brief social break, the club will conduct its membership business meeting.

See the transit of Mercury Monday, November 11

Photo: 2016 Transit of Mercury. Photo by James Guilford
Transit of Mercury, May 9, 2016. A cloudy sky left occasional openings for views of tiny Mercury slowly gliding across the solar disk. Photo by James Guilford.

UPDATE: The Transit of Mercury program planned for Edgewater Park has been canceled due to a forecast of clouds, rain/snow, and below freezing temps. We’ll have to try again in 13 years when the next transit comes around.

The planet Mercury will cross between Earth and Sun on Monday, November 11, 2019. Given clear skies, members of the Cuyahoga Astronomical Association (CAA) will be stationed at the lower level of Edgewater Park offering safe viewing of the event. Viewing times at Edgewater will be from noon until just after 1:00 p.m.

CAA members will be present with their solar-safe telescopes offering several ways of viewing our Sun. Cloudy skies will, of course, cancel the event. No tickets or reservations are required; those interested should simply come to the park. The transit is a natural, astronomical occurrence and cannot be rescheduled; when it has finished, it is finished!

Anyone with eclipse viewing glasses would be able to view the transit but without the magnification offered by a telescope, the event will be hard to see. Mercury, officially a planet, is not quite three times the size of Earth’s Moon. Viewed from Earth, around 48 million miles distant, Mercury is tiny!

The 2019 transit begins at about 7:35 a.m. and will end at 1:04 p.m. November 11. Another transit of Mercury won’t take place for 13 years.

WARNING: NEVER look directly at the sun through binoculars, a telescope, or with your unaided eye. Permanent eye damage and even blindness can result. Astronomers use special filters and glasses to safely observe the sun. Sunglasses, photo negatives, etc. will not protect against eye injury.

Asteroid Hygiea could be classified as a dwarf planet

Image: Asteroid/Dwarf Planet Hygiea. Credit: ESO/P. Vernazza et al./MISTRAL algorithm (ONERA/CNRS)
A new SPHERE/VLT image of Hygiea, which could be the Solar System’s smallest dwarf planet yet. As an object in the main asteroid belt, Hygiea satisfies right away three of the four requirements to be classified as a dwarf planet: it orbits around the Sun, it is not a moon and, unlike a planet, it has not cleared the neighbourhood around its orbit. The final requirement is that it have enough mass that its own gravity pulls it into a roughly spherical shape. This is what VLT observations have now revealed about Hygiea. Credit: ESO/P. Vernazza et al./MISTRAL algorithm (ONERA/CNRS)

Astronomers using ESO’s SPHERE instrument at the Very Large Telescope (VLT) have revealed that the asteroid Hygiea could be classified as a dwarf planet. The object is the fourth largest in the asteroid belt after Ceres, Vesta and Pallas. For the first time, astronomers have observed Hygiea in sufficiently high resolution to study its surface and determine its shape and size. They found that Hygiea is spherical, potentially taking the crown from Ceres as the smallest dwarf planet in the Solar System.

As an object in the main asteroid belt, Hygiea satisfies right away three of the four requirements to be classified as a dwarf planet: it orbits around the Sun, it is not a moon and, unlike a planet, it has not cleared the neighborhood around its orbit. The final requirement is that it has enough mass for its own gravity to pull it into a roughly spherical shape. This is what VLT observations have now revealed about Hygiea.

“Thanks to the unique capability of the SPHERE instrument on the VLT, which is one of the most powerful imaging systems in the world, we could resolve Hygiea’s shape, which turns out to be nearly spherical,” says lead researcher Pierre Vernazza from the Laboratoire d’Astrophysique de Marseille in France. “Thanks to these images, Hygiea may be reclassified as a dwarf planet, so far the smallest in the Solar System.”

The team also used the SPHERE observations to constrain Hygiea’s size, putting its diameter at just over 430 km. Pluto, the most famous of dwarf planets, has a diameter close to 2,400 km, while Ceres is close to 950 km in size.

Surprisingly, the observations also revealed that Hygiea lacks the very large impact crater that scientists expected to see on its surface, the team report in the study published today in Nature Astronomy. Hygiea is the main member of one of the largest asteroid families, with close to 7,000 members that all originated from the same parent body. Astronomers expected the event that led to the formation of this numerous family to have left a large, deep mark on Hygiea.

“This result came as a real surprise as we were expecting the presence of a large impact basin, as is the case on Vesta,” says Vernazza. Although the astronomers observed Hygiea’s surface with a 95 percent coverage, they could only identify two unambiguous craters. “Neither of these two craters could have been caused by the impact that originated the Hygiea family of asteroids whose volume is comparable to that of a 100 km-sized object. They are too small,” explains study co-author Miroslav Brož of the Astronomical Institute of Charles University in Prague, Czech Republic.

The team decided to investigate further. Using numerical simulations, they deduced that Hygiea’s spherical shape and large family of asteroids are likely the result of a major head-on collision with a large projectile of diameter between 75 and 150 km. Their simulations show this violent impact, thought to have occurred about 2 billion years ago, completely shattered the parent body. Once the left-over pieces reassembled, they gave Hygiea its round shape and thousands of companion asteroids. “Such a collision between two large bodies in the asteroid belt is unique in the last 3–4 billion years,” says Pavel Ševeček, a PhD student at the Astronomical Institute of Charles University who also participated in the study.

Studying asteroids in detail has been possible thanks not only to advances in numerical computation, but also to more powerful telescopes. “Thanks to the VLT and the new generation adaptive-optics instrument SPHERE, we are now imaging main belt asteroids with unprecedented resolution, closing the gap between Earth-based and interplanetary mission observations,” Vernazza concludes.

October 21 Membership Meeting: “Apollo 11: Fifty Years Later” (rescheduled)

Jay Reynolds

Our monthly meeting originally scheduled for October 14 at the Rocky River Nature Center was canceled. The nature center parking lot was being resurfaced. The meeting was rescheduled for 7:30 p.m., October 21.

The October 2019 meeting of the Cuyahoga Astronomical Association (CAA) will feature a presentation by club member and Cleveland State University Research Astronomer Jay Reynolds. The historic 1969 Apollo 11 moon landing will be the focus of the talk which will progress into NASA’s next steps in crewed space exploration following the end of the shuttle program.

The CAA’s monthly meetings are held on the second Monday of every month except December at 7:30 p.m. in the Rocky River Nature Center; 24000 Valley Parkway; North Olmsted, Ohio, in the Cleveland Metroparks. Meeting programs are open to the public. Following the presentation and a brief social break, the club will conduct its membership business meeting.

Old Moon rising

Image: Moonrise over Cleveland. Credit: Frank Shoemaker.
Old Moon Rising. Cleveland, Ohio’s downtown skyline with waning Crescent Moon rising. The moon was about 32.5 hours until new. Credit: Frank Shoemaker

This beautiful new shot of an “old” Moon rising was made by Cuyahoga Astronomical Association member Frank Shoemaker. The photographer writes, “I shot this image this morning [September 27] at 5:50.  The moon was about 32.5 hours until new. So far, this is the closest I’ve shot the moon to being new.”

The “new” phase is the end of the lunar cycle aging from Full, and fully-lit, to New and fully-dark; it’s also the beginning of the next cycle, thus New Moon.

“I shot it from the west end of Edgewater Park on the new pier down at the water. I used a Canon 7D Mark II with the 100-400 mm lens at about 260 mm. It’s a single exposure, 2 seconds at f/9, ISO 2000.” Shoemaker explained. “I processed the image through Topaz Labs DeNoise AI and finished it in Lightroom. I planned the shot with the Photographers Ephemeris app.”

 

Final Public Stargaze: October 5

Graphic: International Observe the Moon Night - October 5, 2019
Save the Night: International Observe the Moon Night, October 5, 2019

The year’s final public stargazing session hosted by the Cuyahoga Astronomical Association (CAA) will take place Saturday, October 5, from 8:00 to 10 p.m. at our Letha House Park West observatory site.

Given good sky conditions visitors will be able to view Jupiter, Saturn, star clusters, and Earth’s Moon. In fact, the date coincides with International Observe the Moon Night: a worldwide appreciation of our world’s nearest neighbor in space.

The event is free, open to the public, and is conducted as an “open house” — visitors may arrive and depart at any time during the event’s hours. The CAA’s observatory will be open and association members also will be on hand to share views through their personal telescopes.

An interesting activity any time of year is to make note of the daily changes we see in the phases of Moon. Open the PDF to print a handy guide and journal for lunar observation: Moon Observation Journal.

To find our observatory, and what to expect with a “star party,” visit the following: https://cuyastro.org/caa-observatory/

September 9: Membership Meeting / Dark Matter and Gravity

Photo: Stacy McGaugh.
Dr. Stacy McGaugh. Image Credit: CWRU

The September 2019 meeting of the Cuyahoga Astronomical Association (CAA) will feature a presentation by Dr. Stacy McGaugh, Case Western University Professor and Chair of Astronomy. In “Dark Matter and Gravity in the Universe,” Dr. McGaugh will discuss his work on the search for dark matter and the possibility that it does not exist and we simply do not understand gravity! He has co-authored several papers outlining this controversial view.

The CAA’s monthly meetings are held on the second Monday of every month except December at 7:30 p.m. in the Rocky River Nature Center; 24000 Valley Parkway; North Olmsted, Ohio, in the Cleveland Metroparks. Meeting programs are open to the public. Following the presentation and a brief social break, the club will conduct its membership business meeting.