This is a high rank event and Santa Cruz is on the centerline - but, it's pretty tough. It happens in evening twilight with the sun at -9 degrees and might be too bright to see the target. But, we can try it at home and so there's little investment. The target star is 47 arc sec away from a 13.0 star, so the asteroid+target star at 13.8 will show as a tight double star, near a much brighter star making location easier.
Alt=25 at Az= 121 in SE, north of Sagittarius.
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Karl at 1600 ft elevation at home, had a finger of fog come up slope and obscure the target area while he was trying to get it in the eyepiece. Kirk Bender tried from upper UCSC and was also fogged out. I tried from Sunlit Lane and had clear skies, but the bright twilight made acquiring the target difficult until just before the event. I did get on-target and recording, but it might be too faint to see and reduce. I've not examined the tape yet.
Richard Nolthenius
I observed from Sunlit lane, at the end of the airstrip. The sky was warm, dry, no hint of fog or clouds and no moon. But, plenty of twilight. Doing the 2-star align (Vega and Antares) required waiting till just 15 minutes before the event to start, given bright twilight. Then, when looking into the eyepiece, I could see no stars in the twilight, even the big stars on the chart. I feared the worst, but then saw a star on the left side of the eyepiece, the only one I could see. Then I lost it, and re-located to the coordinates and found it again. I got it centered and then put in the Watec and adjusted the gain and integration until I could see stars, and with a little hesitation, ID'd the stars and got it centered on the target, but the target did not show above the sky. I adjusted the integration to 4x, and then just before the event, to 8x and moved the gain down to 29 as my guess of optimum visibility of the star. This was completed right at the predicted timeo of the event.
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The target star, with the vertical bar on the predicted occultation. You can see only a lack of brighter than average points in the 3 seconds centered on that bar, nothing that would pass significance. So, I tried instead to do 1-sec long finder frame stacks to see if the occultation would show up. See below. |
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A very poor Watec stack of 30 frames of Venus, at very low gain, short exposure, w/o the f/3.3 reducer |
A sequence of 1-second (30 frames each, which is 4 integrations at the 8x setting) finder images. The target star is fairly plain on all images and does seem fainter during the expected occultation period. The image names are the time shown on the Finder, which is the first frame of the finder
4:20:23.02 looks full brightness |
4:20:24.02 looks faint, but so does the neighbor, likely bad seeing. |
4:20:25.03 looks full brightness |
 4:20:26.03 looks full brightness |
4:20:27.03 looks dimmer but so does the neighbor, and more smeared. Likely bad seeing. |
4:20:28.03 looks normal vs the neighbor, both are fuzzier and dimmer looking |
4:20:29.03 looks normal full brightness |
4:20:30.03 looks much dimmer. Neighbor looks normal brightness. Occultation appears to have begun |
4:20:31.03 - Looks dimmer but also spread more, unclear how much dimmer than normal |
4:20:32.03 looks dimmer but also more spread out, while neighbor is sharp. |
4:20:33.03 looks dimmer but so does neighbor |
4:20:34.03 - looks normal vs the neighbor; both looks a little smeared and dimmer together. Probably occultation is over. |
4:20:35.03 - looks full brightness vs neighbor |
4:20:36.03 - looks normal full brightness |
4:20:37.03 - looks normal full brightness |
4:20:38.03 - looks normal full brightness |
4:20:39.04 looks very dim but so does the neighbor. Hard to tell. |
4:20:40.03 - looks normal full brightness |
4:20:41.04 - looks normal full brightness |
4:20:42.04 looks very dim but so does the neithbor stars. Unable to judge |
4:20:43.04 looks normal vs neighbor |
4:20:44.04 looks fatter vs neighbor, probably normal light if integrate over the fatter area of pixels over which it is spread |
4:20:45.04 looks normal brightness. |
