The Occultation of a W=12.6 Star for 13s by Asteroid Circe

Thur eve Dec 11, 2025 at 8:30:47pm

OWc page

 

This is a moderatly difficult event and will require care in settings of your camera. Circe is V=12.4 and the target star is W=12.6, so the drop is 0.5 mag from total magnitude of 11.8. The object will drop from 11.8 down to 12.3 or so and stay there for about 10s. The altitude is low; 20 degree in the NE in Gemini

Alt=20, Az=86; 4 degrees below Alhena (Gamma Gem, Pollux's foot). Try to use Alhena as one of your alignment stars.

     

 

Results:

Clear skies and wide path. Kirk, me, Karl and probably Bernard all got recordings.

Richard Nolthenius

I got a good recording in wavy blurry seeing from inside the neighbor's carport, looking over the roof of the eastern wing of my complex. Not ideal, but it sounds like Karl's seeing from Water Truck Turn was no better. Recorded at 4x, didn't adjust the recording brightness nor contrast from it's prior setting, due to time pressure. Still, it should be easy. Bright star at 4x in clean skies. Looked about 12s long and cut to half brightness, visually.

I expanded the mask to 3.2px to account for the blurrier stars. I also did not use the median horizontal and vertical filter this time in PyMovie. There were a few drops to zero in the light curve. Too many to be real, and occultations were partial anyway. Still I will check to see if any line up with Kirk's data.

magDrop report: percentDrop: 41.1 magDrop: 0.575 +/- 0.074 (0.95 ci)

DNR: 1.50

D time: [04:30:40.4115]
D: 0.6800 containment intervals: {+/- 0.1023} seconds
D: 0.9500 containment intervals: {+/- 0.4409} seconds
D: 0.9973 containment intervals: {+/- 1.0874} seconds

R time: [04:30:51.2915]
R: 0.6800 containment intervals: {+/- 0.1023} seconds
R: 0.9500 containment intervals: {+/- 0.4409} seconds
R: 0.9973 containment intervals: {+/- 1.0874} seconds

Duration (R - D): 10.8800 seconds
Duration: 0.6800 containment intervals: {+/- 0.2014} seconds
Duration: 0.9500 containment intervals: {+/- 0.6174} seconds
Duration: 0.9973 containment intervals: {+/- 1.3409} seconds


Kirk Bender

I got an 11.6782 sec event for Circe, Dec. 11, 4x at the BD Eco Reserve.


NIE sigma 15.3
magDrop report: percentDrop: 31.8  magDrop: 0.415  +/- 0.052  (0.95 ci)

DNR: 1.27

D time: [04:30:39.7755]
D: 0.6800 containment intervals:  {+/- 0.1479} seconds
D: 0.9500 containment intervals:  {+/- 0.5879} seconds
D: 0.9973 containment intervals:  {+/- 1.4767} seconds

R time: [04:30:51.4537]
R: 0.6800 containment intervals:  {+/- 0.1479} seconds
R: 0.9500 containment intervals:  {+/- 0.5879} seconds
R: 0.9973 containment intervals:  {+/- 1.4767} seconds

Duration (R - D): 11.6782 seconds
Duration: 0.6800 containment intervals:  {+/- 0.2767} seconds
Duration: 0.9500 containment intervals:  {+/- 0.8334} seconds
Duration: 0.9973 containment intervals:  {+/- 1.7832} seconds

       

 

Karl von Ahnen

Observed from Water Truck Turn at 4x

magDrop report: percentDrop: 43.4  magDrop: 0.619  +/- 0.067  (0.95 ci)

DNR: 1.26

D time: [04:30:39.1584]
D: 0.6800 containment intervals:  {+/- 0.1142} seconds
D: 0.9500 containment intervals:  {+/- 0.4981} seconds
D: 0.9973 containment intervals:  {+/- 1.3067} seconds

R time: [04:30:50.5698]
R: 0.6800 containment intervals:  {+/- 0.1142} seconds
R: 0.9500 containment intervals:  {+/- 0.4981} seconds
R: 0.9973 containment intervals:  {+/- 1.3067} seconds

Duration (R - D): 11.4114 seconds
Duration: 0.6800 containment intervals:  {+/- 0.1917} seconds
Duration: 0.9500 containment intervals:  {+/- 0.6236} seconds
Duration: 0.9973 containment intervals:  {+/- 1.3545} seconds