This event happens just as my Astro 3-2 class is ending, at Cabrillo. If the clouds look to stay away, I may be able to end early and get this from outside the classroom. The RUWE is 2.6, above the 1.2 limit for safety in the star's astrometry, so the path shift could be significant, while yet the formal uncertainty in the path is quite low. I'll guess that anyone in the Santa Cruz area has about a 50% chance of not having a miss.
The altitude=23 and Az=211 in SW, no sun or moonlight.
|
|
We had clear skies at Cabrillo College, no fog. Kirk however saw some clouds coming in and worried they may bring fog, and drove up Empire Grade to upper UCSC meadow bike crossing with clear skies. I had Astro 3-2 to teach from 6-9pm and so planned to end class a little early, head them up to the Planetarium where I showed them how the stars and planets move, and then told them about this special event and to stay a few minutes late to watch how data is taken. Some did, and some had buses to catch, etc. I drove my car on the utility road to right next to the classroom and set up as per normal out of the back of my RAV4. 5 of my most interested young students were happy to chat and ask questions and watch as I set up and aligned the 8SE scope and got the video gear going, and were very engaged to try and watch the very dim star on the LCD monitor and see if it disappeared for 2s as I hoped. As it turned out, we couldn't completely tell (it was very dim, and light pollution from the football field practice and campus lighting). I promised I'd bring in the light curves and pictures to share and explain at the next week's class meeting.
I used the TME mask option in PyMovie. It went very very slow; over a half hour on my laptop to finish the 5 minutes of 16x data, but, it did seem to give surprisingly good results on the target star. On the view on-screen, the star was usually lost in the bright sky noise, although quite clearly there on the Fourier finder frame I first created. The final light curve was quite nicely distinctly above zero, and so I'm confident I had a miss.
Astro 3 students, happy for a little extra credit seeing our Astro gear gathering good science. |
Now if only we can get lucky with this asteroid... |
The target was EXTREMELY difficult to see, even at 16x. Bright sky didn't help. I was afraid the star data would be completely lost in the bright sky. |
But in fact, the new TME method of selecting optimal pixels for measurement, did a pretty good job of producing a light curve separated from the empty sky light curve (red). |
I used 16x, sharpness=4,Gain=41, Gamma=1. This is the target star light curve |
PyOTE data for the target |
And, calibrated using a nearby unsaturated reference star. The focus was poor, despite spending time trying to optimize. Heat from the roof of the Cafeteria building?? |
Zoomed in, and showing what a perfect photometric light curve would look like if there was a maximal event. Conclusion: a miss. |
Observed under good dark conditions in thinner air 1000 ft up, at the bike crossing upper meadow UCSC, and had a clear miss as well. He was farther from the nominal path than I, so not really surprising. Kirk's data looks lower noise, better than mine. But he had darker skies, in addition to a better camera. He used the static aperture standard PyMovie procedure.
PyMovie composite light curves. Gold is the target star |
Target star light curve alone. |
And, in PyOTE. |
The V magnitude was 13.73 and the R magnitude 12.81, so halfway is 13.3 was the Watec-band magnitude, or W=13.3. Good to note for reference for the future. This event did not have smokey skies and did not have a moon nearby, but it did have the football field lights on, and Capitola lights as well.
