Cronyn Observatory Public Night, Saturday, August 23rd, 2014

Clear skies enticed a good crowd to the Cronyn Observatory; however, as dusk set in fast-moving clouds from the northeast almost completely obscured the sky for about an hour. It was only towards 10:00 p.m. that the clouds dissipated, finally allowing an unobstructed view of a fairly transparent, clear sky with good seeing.

Postdoctoral fellow Sofia Lianou made her digital slide presentation "Colors in the Universe" and fielded questions. There were 40 visitors for the first slide lecture. Sofia repeated her lecture four more times over the course of the evening, for a total of five presentations. According to Sofia, the second presentation attracted 10 people, the third presentation attracted 4 people, the fourth presentation attracted 5 people, and she gave the last presentation to two people who seemed very keen.

Not everyone who came to Cronyn attended the lectures. In total, precisely 100 people attended, as counted by Graduate student Sayantan Auddy, who was crowd manager. Graduate student Emily McCullough helped out by unlocking the dome, and assisting where needed. Graduate student Tony Martinez was telescope operator for the big 25.4cm refractor. RASC London Centre was represented by Dale Armstrong, Eric Clinton, and Mark Tovey.

For most of the evening, Tony showed visitors Saturn through the 25.4cm refractor in the dome. Saturn was viewed on the 32mm Erfle (137X) eyepiece. Titan was observed very clearly. By the time Saturn was just visible in the late evening sky it became hard to find because of patchy cloud, but Tony was able to lock on to it in an extended clear patch after about 20 minutes. The clouds became thicker but still variable which meant that after dusk members of the public were often a minute or so viewing through the large refractor before seeing Saturn, often with exclamations of how beautiful it was. The thick patchy cloud continued for most of the night and then gradually cleared. Once the crowds and clouds had cleared and all those in the dome had seen Saturn, Tony started moving to other objects with the large refractor. Using the 32mm Erfle (137X), visitors also got a view of Epsilon Lyrae (the "Double Double") with a two-way split. Epsilon Lyrae was split into its four components in the refractor by switching to the 18mm Radian (244X). Tony noted that the view in the 18mm was "crystal clear, just beautiful the way it separated." M57, also viewed using the 18mm Radian (244X), was "very faint, but still quite respectable". That object was kept in view until the end of the night. The diameter of the 18mm eyepiece is less than the standard eyepieces, so a 1.25-inch adapter was used. Tony reported that "we had a lot of happy people go through the Observatory" on Saturday.

Dale set up the Observatory’s 8-inch (20.3cm) Meade 2080/LX3 Schmidt-Cassegrain on the east of the deck (usually it is set up on the west) to facilitate viewing Saturn and Mars, which would have otherwise been invisible behind the engineering building. Dale remained with the Schmidt-Cassegrain throughout the evening. He started off showing visitors Mars at 320X using the 12.5mm Ortho (160X) and the 2X Barlow, later switching to Vega, using the 15mm Sky-Watcher UltraWide (133X), for a considerable length of time due to the heavy cloud cover. A few gaps in the clouds allowed him to move over to Saturn (133X) for awhile before it disappeared behind the engineering building. Thereafter, he pointed the telescope at Mizar and Alcor, still using the 15mm eyepiece. When the sky finally began to clear towards 10:00 p.m., Dale acquired M13, and later M15 with the 15mm eyepiece (133X). Thereafter, M57 was observed using the 20mm Plossl (100X). Towards 11:00 p.m. the final few visitors were treated to Albireo with the 15mm Plossl.

Eric Clinton, assisted by Ben Clinton, set up his Celestron C5 (12.7cm) Schmidt-Cassegrain (f.l. = 1,250mm) on the deck. They showed visitors Mars and Saturn through the 7mm Nagler (178X), the 12mm Nagler2 (104X) and the 25mm Plossl (50X). Albireo was viewed using the 25mm Plossl (50X) and M57 was also viewed at this power. Only a few saw Mars. About twenty people saw Saturn in the C5. Twenty people observed Albireo. Five observed the Ring Nebula. Ben Clinton showed visitors constellations on his iPod app.

Mark set up the 25.4cm Dobsonian and 17mm Nagler eyepiece (66X) on the deck. The scope was transferred to the sidewalk in front of Cronyn to facilitate the viewing of Saturn by a visitor in a wheelchair who was unable to come up to the deck. Mark remained outside with this scope throughout the evening. When skies were too cloudy for observation, Mark explained the 25.4cm Dobsonian, and its connection to sidewalk astronomy, presenting to groups of visitors on five occasions. Group sizes for the explanation were fourteen, five, four, two, and one, respectively, for a total of twenty-six people. Saturn was viewed through the 17mm Nagler eyepiece (66X). Rings were distinctly visible at this power, although Saturn was small. Cloud conditions made it difficult to even view single stars in the early evening; however, Mark showed Vega and Ruchbah (in Cassiopeia) to visitors with this eyepiece towards the end of the evening.

An ISS pass was observed in the southwest around 9:08—9:14 p.m. The ISS signal in the dome proved a distraction in locating a faint object in the 25.4cm refractor in the dome, so two people were asked to stand in front of the flashing light while acquiring that object. A second ISS pass was signaled in the dome sometime before 11:00 p.m. The six visitors who remained at that hour briefly looked for the ISS on the deck without seeing anything. Mark consulted the GoISSWatch app on an iPod. The app suggested that a visible ISS pass was not due at that time, and the search was discontinued.

Not observed, likely due to cloud conditions, but looked for by two visitors on the sidewalk outside Cronyn, were two Iridium flares at around 8:58 p.m. While packing up, Eric and Dale observed a bright meteor that streaked overhead, reaching magnitude minus 2 or 3. The visitors were gone by around 11:00 p.m., and everybody packed up and left the Observatory around 11:30 p.m., after a very informative and enjoyable evening of astronomy despite partly cloudy skies.

Note: Visible ISS Pass and Iridium Flares, for London, Ontario, August 23rd, 2014

By Robert Duff

There was an ISS pass over London, Ontario, August 23rd, 2014 (listed on the Heavens Above, ISS – Visible Passes Web site), travelling from west-northwest to south-southeast, around 9:08—9:14 p.m., reaching 30 degrees maximum altitude (~9:11 p.m.) in the southwest. There were also 2 Iridium flares over London, Ontario, August 23rd, 2014, including the Iridium 18 satellite flare at 8:58:43 p.m. (altitude 69 degrees) in the east-southeast, and the Iridium 98 satellite flare at 8:58:55 p.m. (altitude 67 degrees) in the east southeast (both listed the Heavens Above, Iridium Flares Web site). 

Report by Mark Tovey, Edited by Robert Duff