Beautiful M42 in crystalline skies

Orion Nebula, M42, by Hayden Gill. February 2020

Hayden Gill, a member of our Cuyahoga Astronomical Association (CAA) braved a very cold but crystal-clear February night collecting image data to create this picture; it was also his very successful first effort at image stacking.

Gill wrote: “I shot it with a Nikon D7200 on a SkyWatcher EvoStar 80ED {telescope}, CGEM II mount. For guiding I have a 60mm ZWO scope and a ZWO 174 mono” guide camera. He used his Nikon for the data capture and Deep Sky Stacker to build the image. Each exposure was two minutes at ISO 800. He used 34 light images, 20 darks, 20 flats, 25 bias frames. Post processing was in Photoshop.

“This was my first attempt at astrophotography stacking. First time stacking and first time really putting all my gear to use how I have been intending to. Can’t wait to get back out!”

We will be eager to see Gill’s continued progress and images!

February 10 Membership Meeting: “Lucy in the Sky with Asteroids”

An artist’s concept of the Lucy Mission. Credit: SwRI

On Monday, February 10, at 7:30 p.m. the Cuyahoga Astronomical Association (CAA) will conduct its monthly club meeting. The meeting will feature a talk by CAA member Kai Getrost, a member of the special NASA teams that performed occultation studies in support of NASA’s New Horizon’s space probe to “Ultima Thule.” He is currently working in support of NASA’s Lucy Mission to explore Jupiter’s Trojan Asteroids. The Lucy spacecraft will launch in October 2021 and, with boosts from Earth’s gravity, will complete a 12-year journey to seven different asteroids.

As part of the NASA science teams in support of the New Horizons and Lucy Missions, Getrost has traveled to South America and to Australia to help gather occultation data used to help guide the spacecraft.

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

First meeting of the new decade: January 13, 2020

Photo: After sunset scopes pointed skyward and offered views of planets Jupiter, Mars, and Saturn. Photo by James Guilford.
After sunset scopes pointed skyward and offered views of planets Jupiter, Mars, and Saturn.

The first Membership Meeting of the Cuyahoga Astronomical Association (CAA) for 2020 will take place Monday, January 13. The meeting will feature a presentation by member Trevor Braun entitled, “Equipment for Amateur Astronomy 101.” Are you looking to buy a new, or perhaps upgrade/enhance your existing, telescope? Learn about the critical factors needed to make a decision, as well as some of the equipment and accessories you may want to consider as you begin to get ready for the 2020 observing season.

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.

Europa: Improved image from Galileo mission

Galileo’s Europa Remastered. Image Credit: NASA, JPL-Caltech, SETI Institute, Cynthia Phillips, Marty Valenti

“Looping through the Jovian system in the late 1990s, the Galileo spacecraft recorded stunning views of Europa and uncovered evidence that the moon’s icy surface likely hides a deep, global ocean. Galileo‘s Europa image data has been remastered here, using improved new calibrations to produce a color image approximating what the human eye might see. Europa’s long curving fractures hint at the subsurface liquid water. The tidal flexing the large moon experiences in its elliptical orbit around Jupiter supplies the energy to keep the ocean liquid. But more tantalizing is the possibility that even in the absence of sunlight that process could also supply the energy to support life, making Europa one of the best places to look for life beyond Earth. What kind of life could thrive in a deep, dark, subsurface ocean?” — Via APOD: Astronomy Picture Of the Day

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.