by Joe Fragola
Some earlier family activities did not permit me to get out to a dark sky site, so I was confined to my front yard (in S. San Jose) for Saturday night viewing of asteroid 2002 NY40. I had the PDF finder charts which I downloaded from the Sky & Telescope Web site, as well as my Starry Night Pro planetarium software to help me track down this fast moving visitor to our neck of the Solar System. Since we’re in a typical summertime weather pattern here in northern California, that meant that clouds would be spreading inland from the Pacific Ocean before the midnight hour struck. Therefore, my plan was to start searching for NY40 as soon as possible.
I set out my Orion SkyQuest XT10 Dobsonian in the driveway to start cooling down around 8:00 p.m. PDT. While I was waiting for the sky to darken, I spent time checking my charts. At 8:50 p.m. PDT I observed a mag. 2.1 pass of the ISS that took it just above Venus and slightly below Spica which were both setting into the waning western twilight. A nice “appetizer” to the “main course” which was to follow. The First Quarter Moon was in the south among the stars of Sagittarius. I could already see the stars of the “Summer Triangle” - Deneb, Altair, and Vega high overhead.
My finder charts showed NY40 would be located very close to kappa Lyrae (magnitude 4.3) around 9:05 p.m. I centered Vega in my finder scope and then proceeded to move over to kappa Lyrae. I was amazed to see the asteroid enter the field of view almost on time. Later as I continued to track the asteroid and compare predicted times on my finder charts with actual times, I found that the predictions were off by almost 2 minutes (I didn’t time it exactly). I didn’t expect NY40 to be flying across the field of view so fast. There was no doubt as to which object in the field of view was the asteroid. Only several seconds of viewing were required to show the obvious motion against the background stars. To my eye, the asteroid had a slightly brownish/ orange tint to it.
It was very cool to watch as this “space rock” made its way through the changing pattern of background stars. I ended up tracking NY40 for about 45 minutes across the Lyra border into the stars of the constellation Hercules. Unfortunately, around 9:50 p.m. the asteroid passed into “Dobson’s Hole” - the area of the sky directly overhead where tracking objects with a Dobsonian mount is not possible. I decided to take a break which ended up being permanent.
The clouds had started to roll in over the coastal hills. By 10:30 p.m. the sky was completed clouded over. As I packed up the scope, I was very happy to have had the opportunity to spent some time viewing this speedy celestial visitor. I’m looking forward to reading other observing reports about this event.