Aug 21, 2008 UT: No result for occultation by asteroid (27) Euterpe

Michael Richmond
Aug 23, 2008

On the night of August 20/21, 2008, the asteroid (27) Euterpe was predicted to occult the star 2UCAC 39820521 for observers in the northeast US and central Canada. The predicted path ran right over RIT.

Map courtesy of Steve Preston -- see the Asteroid Occultation Update page for upcoming events.

The RIT Observatory near Rochester, New York,

fell about 22 kilometers south of the center of the predicted shadow track (shown by the blue line in the map below). The red lines show the predicted edges of the path.

From an interactive map courtesy of Global Occultation Maps ; thanks to Derek Breit.

The setup was:

I arrived seven hours early to set everything up during the early evening; I could then get some sleep before returning at 3:30 AM. I placed a PC-164C video camera on the back of the 12-inch telescope and ran the signal through a Kiwi OSD video time insertion unit: it places GPS-derived timestamps on every frame of the video. The unit picked up a GPS lock just fine. There were no problems with the equipment.

When I returned at 3:30 AM, I tried to find the field. I sync'ed the telescope on nearby mu Gem, then drove the telescope to the target's location. Unfortunately, I could only see one star on the monitor screen, not enough to identify the field. The finding chart for this field indicates that there should have been several stars as bright as the target:

            Tycho-2            USNO B1.0        GSC 1.2
  star     Bt     Vt         B     R     I        Pmag
    A      9.7    9.2
    B     12.4   10.9
    C     10.4    9.9

 target                    12.4  10.3  10.8      11.6

I don't think that the USNO B1.0 magnitudes for the target star are accurate, since it looks much fainter than the stars A, B, C in the POSS plate. The GSC mag seems more likely.

In any case, I couldn't identify the field. Possible factors were

At least I confirmed that all the video-recording equipment is working properly.