Just after midnight on the night of July 6/7, 2003, the asteroid (576) Emanuela was forecast to pass in front of the tenth magnitude star TYC 5236-01194-1 for observers in portions of the Northeast US. As you can see on the map below, the event would occur very low in the sky, just as the star was rising in the East.
This table of information confirms that the event would take place very low in the sky:
Path Coordinates:
Occultation of TYC 5236-01194-1 by 576 Emanuela on 2003 Jul 07
Centre Star Star Sun Path Limits Error Limits
E. Longitude Latitude U.T. Alt Az Alt Limit 1 Limit 2 Limit 3 Limit 4
o ' " o ' " h m s o o o o ' " o ' " o ' " o ' "
Longitude Longitude Longitude Longitude
- 95 50 8 49 0 0 4 27 51 2 97 -14 - 91 30 37 ... .. .. - 91 30 37 ... .. ..
- 89 30 53 48 0 0 4 27 42 6 101 -16 - 87 0 19 - 92 43 14 - 87 0 19 - 92 43 14
- 85 42 24 47 0 0 4 27 32 9 104 -18 - 83 45 13 - 87 56 14 - 83 45 13 - 87 56 14
- 82 47 33 46 0 0 4 27 21 11 106 -20 - 81 8 16 - 84 36 23 - 81 8 16 - 84 36 23
- 80 23 29 45 0 0 4 27 10 13 108 -21 - 78 55 46 - 81 57 35 - 78 55 46 - 81 57 35
- 78 20 14 44 0 0 4 26 58 14 109 -22 - 77 0 47 - 79 44 21 - 77 0 47 - 79 44 21
(RIT Observatory here)
- 76 32 23 43 0 0 4 26 45 16 110 -24 - 75 19 12 - 77 49 10 - 75 19 12 - 77 49 10
- 74 56 33 42 0 0 4 26 32 17 111 -25 - 73 48 20 - 76 7 41 - 73 48 20 - 76 7 41
- 73 30 28 41 0 0 4 26 19 19 112 -26 - 72 26 17 - 74 37 3 - 72 26 17 - 74 37 3
- 72 12 29 40 0 0 4 26 6 20 112 -27 - 71 11 41 - 73 15 21 - 71 11 41 - 73 15 21
I wondered if we could see this location in sky, only 15 degrees above the eastern horizon, but it turns out that this happens to be a good spot: it's just to the right of a big pine tree, and to the left of a smaller tree, directly over the Observatory House as seen from the 12-inch dome.
I used the Pulnix intensified CCD video camera on the back of the 12-inch Meade LX-200 at Cass focus. Even at this very low elevation (the airmass was around 3.8!), I could see clearly on the video screen the target star (marked A on the chart below) and two companions (B and C):
The stars have magnitudes in the Tycho-2 catalog:
star Bt Vt
-----------------------
A 11.2 10.0
B 12.6 11.9
C 13.5 11.9
I used a video-capture program to save video as a stream of 6 frames per second, in AVI format, at a size of 320x240 pixels. The video looked decent on the screen of the computer as it was captured or previewed, but when I watched it later, it was awful: the software had compressed the signal in a way that made star A difficult to see and stars B and especially C nearly invisible. In the future, it's probably better to save the signal as individual JPG frames once per second (at a high quality) than use the AVI option, even though that gives higher time resolution.
I started recording at 12:14 AM and stopped at 12:34 AM. The event was scheduled to occur around 12:26:50 AM, but I didn't see anything as I watched. The stars were all twinkling and dancing around because they were so low in the sky, but the occultation should have made star A drop by 3.1 magnitudes for up to 14 seconds. That would have made it total invisible. I didn't see any such dramatic change.
Oh, well. I reported my null result to David Dunham, who organized a campaign to observe this event. I'll check with him later to see what happened at other sites.