Wide field view of the target area in Leo
Bright target, but an equally bright reference star is just to the upper right, and should be a good ref and tracking star both.
This is our 3rd bright-star occultation of the week. A rare treat! This target is in Leo. Duration is 1.0 seconds, I again recommend using 1x setting. Adjust the gain down a bit to guarantee no saturation. Magnitude 8.4 is quite bright and will be saturated even at 1x on a Watec 910hx. If the star has a measurable diameter, you'll want to avoide saturation for sure. You cannot get better time resolution than 1x, so do not go below an exposure of 1/60s (EIA) or 1/50s (PAL) - it's just throwing away photons for no good reason. Adjust gain downward and you'll preserve signal to noise and also avoid saturation. If you have lots and lots of pixels (Bernard), and perhaps 16 bit camera too, the don't worry about saturation perhaps.
Alt=23, Az=279 Due west, in Leo just 2 degrees above the classic binary Gamma Leonis in the neck of Leo.
Notice too that Mars and Regulus are in close conjunction tonight, less than a degree apart. Take some photos, and don't worry that Leo doesn't look the same.
Wide field view of the target area in Leo |
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Bright target, but an equally bright reference star is just to the upper right, and should be a good ref and tracking star both. |
Clear skies and no wind, dry, perfect conditions for this bright star event.
I got a successful occultation, estimated about 0.7s. At 1x, from Llama Lane in Cave Gulch, just east of the faint curvy path, inside the parking area of a place with a fence and trees. Western-most tree was opposite me.
The PyMovie light curve shows the light drop was instantaneous, and I see no Fresnel diffraction tell-tale signs, so I used the square wave model
magDrop report: percentDrop: 99.9 magDrop: 7.472 +/- 1.333 (0.95 ci)
DNR: 4.12
D time: [05:58:53.1779]
D: 0.6800 containment intervals: {+/- 0.0044} seconds
D: 0.9500 containment intervals: {+/- 0.0119} seconds
D: 0.9973 containment intervals: {+/- 0.0226} seconds
R time: [05:58:53.8690]
R: 0.6800 containment intervals: {+/- 0.0044} seconds
R: 0.9500 containment intervals: {+/- 0.0119} seconds
R: 0.9973 containment intervals: {+/- 0.0226} seconds
Duration (R - D): 0.6910 seconds
Duration: 0.6800 containment intervals: {+/- 0.0067} seconds
Duration: 0.9500 containment intervals: {+/- 0.0154} seconds
Duration: 0.9973 containment intervals: {+/- 0.0262} seconds
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Got a positive.