This very rare event - the only such Titan event for the rest of my life! - an valuable for calibrating occultation data against the excellent Huygens Probe data from the Cassini Mission, will be easily recordable by 8" scopes. The best sites for slow and therefore high time resolution information is near the limits. It turns out this path is very wide, hitting the Earth straight on, and the limits go through central South America on the south, and through Santa Cruz, CA on the north end. It's best to get inside the "hard shadow" to make sure we see the entire atmosphere. Many observers will be trying it, including maybe the 40" Nickel scope at Lick Observatory. Kirk and I will try it from somwhere south of Santa Cruz depending on the clouds.
A full central occultation would last 326 seconds. For us near the limits, less than 1 minute, with most of that being in the atmosphere. Very much like the Pluto Event we got from FPO in 2019. Central occultation is close to 2:21:22am but they don't give predictions for anything closer than Lemoore, CA. We should record for a good 10 minutes centered on 2:21:22
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"Team Santa Cruz" came through! We got data from Karl at home, and me and Kirk in Tres Pinos and Paicines, respectively. Kirk was my co-pilot as we heade down for a marathon of occultations Friday night / Saturday pre-dawn, in San Benito County. The Titan event, at least, looks like a success.
Kirk Bender's results
Kirk got very nice data from Hwy 25 and Cienega Rd, at the "white bicycle" death marker. As this data is going to the LuckyStar people for more detailed reductions, it was important to record a "flat field video" and also a "dark field video" for both the occultation itself, and a separate "dark field video" for the flat field. The reason you need separate darks is because they are sensitive to the temperature, so you want the dark field video to be taken right after the occultation, which both Kirk and I did. The flat field requires a clean sky and exposure at a short enough exposure level to be in the linear range of the detector, whatever that turns out to be.
Star "A" (green), Titan (yellow) and sky (black), Rhea (red), in PyMovie |
Titan alone, in PyMovie |
PyOTE reduction, in field mode. Took ~2.5 hours for PyOTE to complete!! The sharp spike at the onset of D and R are real, due to refraction of the starlight all the way around Titan from the opposite diamter, and focusing to a caustic, to add to the light of the nearly unobscured primary image caustic. Other light curves from this event show this as well. Valuable info on the atmosphere here! |
With the "Star A" as a smoothed comparison star. Those spikes in brightness in Titan are not in the comparison star and look quite real! Atmospheric structure is showing through - excellent work! This one took 10 hrs in PyOTE. The large dip in both the green (star "A") and blue (Titan) light curves during the D was likely a tripod bump. So this required correction by smoothing the green curve as comparison. |
Zoomed in on the area around the "D", looking at those spikes. |
Same data. Zoomed in a little tighter for better visualizing the time resolution, around the D. |
Atmospheric spikes near the R as well! |
