Photo: Nearly Full Perigee (aka "supermoon")  - November 13, 2016, 5:52 PM. Photo by James Guilford.

Shortly After Rising: Nearly Full Perigee (aka “supermoon”) Moon – November 13, 2016, 5:52 PM

We’ve said it before, usually too much is made of so-called “supermoon” occasions; they happen with fair regularity and have little astronomical significance, and an astrologer invented the term.

Supermoons are also known as perigee Full Moons — times when Earth’s Moon reaches its full phase and the low point in its orbit (closest to Earth) at the same time. Our Moon is on an elliptical orbit that carries it nearer and farther from Earth, the distance constantly changing as it travels along its path. Perigee Full Moons, because they are somewhat closer to Earth, mean the Moon looks bigger, brighter, and will have an increased influence on ocean tides.

Tonight’s Full Moon, however, may just deserve the supermoon moniker: it will be the closest Full Moon since 1948, floating 221,524 miles (356,509 km) away. We won’t have another perigee Full Moon so close until 2034.

Technically, the Moon reaches perigee (low point in an orbit) tomorrow morning. According to an article from NASA, “The biggest and brightest Moon for observers in the United States will be on Monday morning just before dawn. On Monday, Nov. 14, the moon is at perigee at 6:22 a.m. EST and “opposite” the sun for the full moon at 8:52 a.m. EST (after moonset for most of the US).” The farthest our Moon traveled from us this year was to an apogee (high point of orbit) of 252,688 miles on October 31.

Tonight’s Moon will be brilliant, as it is every time it reaches Full, but many folks won’t really notice the 14 percent larger appearance and 30 percent difference in brightness. Still, the interest is good and our amazing and beautiful nearest neighbor in space deserves the appreciation!

Due to scheduling difficulties, there will be no November Open Night at the observatory. We regret we are unable to offer a program this month but hope to offer public observing in December. Thank you for your interest!

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UPDATE: Only a handful of guests visited – too much competition from sports events – but those who came had superb views of Moon, good views of the Andromeda Galaxy and Perseus Double Cluster later.

Stephens Memorial Observatory of Hiram College will be open for public observing Saturday, October 8, from 7:00 to 9:00 PM. Focus of the night will be Earth’s Moon and part of this year’s International Observe the Moon Night.

International Observe the Moon Night (InOMN) is an annual worldwide public event that encourages observation, appreciation, and understanding of our Moon — the same moon seen around the world by all people.

While the Moon will be the “star” of the night, other night sky gems may also be offered for viewing through the observatory’s large vintage telescope.

No reservations are required and there is no admission fee for observatory public nights. Cloudy skies at the starting time cancel the event and, in that case, the observatory will not open.

The Observatory is located on Wakefield Road (Rt. 82) less than a quarter of a mile west of Route 700 in Hiram. There is no parking at the Observatory. Visitors may park on permissible side streets near the Post Office, a short distance east of the observatory.

Tonight’s planned Public Night is CANCELED due to inclement weather conditions and overcast skies expected to continue into late-night.

Astronomers using ESO telescopes and other facilities have found clear evidence of a planet orbiting the nearest star to our own Sun, Proxima Centauri. The long-sought world, designated Proxima b, orbits its cool red parent star every 11 days and has a temperature possibly suitable for liquid water to exist on its surface. This rocky world is a little more massive than the Earth and is the closest exoplanet to us — and it may also be the closest possible abode for life outside the Solar System. A paper describing this milestone finding will be published in the journal Nature on 25 August 2016.

Just over four light-years from the Solar System lies the red dwarf star named Proxima Centauri as it is the closest star to Earth apart from the Sun. This cool star, in the southern hemisphere constellation of Centaurus, is too faint to be seen with the unaided eye and lies near to the much brighter pair of stars known as Alpha Centauri AB.

During the first half of 2016 Proxima Centauri was regularly observed with the HARPS spectrograph on the ESO 3.6-metre telescope at La Silla in Chile and simultaneously monitored by other telescopes around the world. This was the Pale Red Dot Campaign, in which a team of astronomers led by Guillem Anglada-Escudé, from Queen Mary University of London, was looking for the tiny back and forth wobble of the star that would be caused by the gravitational pull of a possible orbiting planet.

As this was a topic with very wide public interest, the progress of the campaign between mid-January and April 2016 was shared publicly as it happened on the Pale Red Dot website and via social media. The reports were accompanied by numerous outreach articles written by specialists around the world.

Guillem Anglada-Escudé explains the background to this unique search: “The first hints of a possible planet were spotted back in 2013, but the detection was not convincing. Since then we have worked hard to get further observations off the ground with help from ESO and others. The recent Pale Red Dot campaign has been about two years in the planning.”
The Pale Red Dot data, when combined with earlier observations made at ESO observatories and elsewhere, revealed the clear signal of a truly exciting result.

At times Proxima Centauri is approaching Earth at about five kilometers per hour — normal human walking pace — and at times receding at the same speed. This regular pattern of changing radial velocities repeats with a period of 11.2 days. Careful analysis of the resulting tiny Doppler shifts showed that they indicated the presence of a planet with a mass at least 1.3 times that of the Earth, orbiting about seven million kilometers from Proxima Centauri — only five percent of the Earth-Sun distance.

Guillem Anglada-Escudé comments on the excitement of the last few months: “I kept checking the consistency of the signal every single day during the 60 nights of the Pale Red Dot Campaign. The first 10 were promising, the first 20 were consistent with expectations, and at 30 days the result was pretty much definitive, so we started drafting the paper!”

Red dwarfs like Proxima Centauri are active stars and can vary in ways that would mimic the presence of a planet. To exclude this possibility the team also monitored the changing brightness of the star very carefully during the campaign using the ASH2 telescope at the San Pedro de Atacama Celestial Explorations Observatory in Chile and the Las Cumbres Observatory telescope network. Radial velocity data taken when the star was flaring were excluded from the final analysis.

Although Proxima b orbits much closer to its star than Mercury does to the Sun in the Solar System, the star itself is far fainter than the Sun. As a result Proxima b lies well within the habitable zone around the star and has an estimated surface temperature that would allow the presence of liquid water. Despite the temperate orbit of Proxima b, the conditions on the surface may be strongly affected by the ultraviolet and X-ray flares from the star — far more intense than the Earth experiences from the Sun.

Two separate papers discuss the habitability of Proxima b and its climate. They find that the existence of liquid water on the planet today cannot be ruled out and, in such case, it may be present over the surface of the planet only in the sunniest regions, either in an area in the hemisphere of the planet facing the star (synchronous rotation) or in a tropical belt (3:2 resonance rotation). Proxima b’s rotation, the strong radiation from its star and the formation history of the planet makes its climate quite different from that of the Earth, and it is unlikely that Proxima b has seasons.

This discovery will be the beginning of extensive further observations, both with current instruments and with the next generation of giant telescopes such as the European Extremely Large Telescope (E-ELT). Proxima b will be a prime target for the hunt for evidence of life elsewhere in the Universe. Indeed, the Alpha Centauri system is also the target of humankind’s first attempt to travel to another star system, the StarShot project.

Guillem Anglada-Escudé concludes: “Many exoplanets have been found and many more will be found, but searching for the closest potential Earth-analog and succeeding has been the experience of a lifetime for all of us. Many people’s stories and efforts have converged on this discovery. The result is also a tribute to all of them. The search for life on Proxima b comes next…”

Image: Saturn: August 12, 10:00 PM EDT - Simulated view via Gas Giants app

Saturn: August 12, 10:00 PM EDT – Simulated view via Gas Giants app

UPDATE: Due to mostly-cloudy to overcast skies and recurring scattered thunderstorms, this event has been CANCELED. — JG, 8/12/16, 8:00 PM.

Stephens Memorial Observatory of Hiram College will be open for public observing Friday, August 12, from 9:30 to midnight. Hoping to catch the end of the annual Perseid Meteor Shower, the observatory is hosting its monthly public event on this Friday rather than on Saturday night.

Visitors are invited to bring personal lawn chairs and sit out beneath the stars watching for meteors (mosquito repellent is strongly recommended) until midnight. Via telescope, views of beautiful Saturn, and other objects will also be offered. Saturn’s famous ring system is nicely tilted allowing for excellent viewing, given clear skies.

No reservations are required and there is no admission fee for observatory public nights. Cloudy skies at the starting time cancel the event and, in that case, the observatory will not open.

The Observatory is located on Wakefield Road (Rt. 82) less than a quarter of a mile west of Route 700 in Hiram. There is no parking at the Observatory. Visitors may park on permissible side streets near the Post Office, a short distance east of the observatory.

Two-panel Moon

StephensAstro —  July 18, 2016 — Leave a comment
Photo: Earth's Moon two days short of Full. Photo by James Guilford.

Two-Panel Moon: This photograph of the Moon, our latest experiment using the vintage Cooley Telescope in astrophotography, shows the Moon about two days from Full. Two individual shots were made using a Canon DSLR in place of the telescope’s eyepiece, projecting the lunar image directly upon the camera’s sensor. Exposure: ISO 400, 1/320 second. Adobe Photoshop was used to “photomerge” the individual panels or frames and edit the resulting image. [Click image to enlarge.]