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Observers inside a narrow path across Southern England could see the star dim when the asteroid (19021) 2000 SC8 partially occults the v6.7 star.
The predicted time is between 2140 10s and 2140 30s (UT) depending on location in the UK. Observers in the path should see the star dim but not extinguished – at least that is what the prediction suggest. The star has an apparent diameter of 12 mas, while the asteroid is 5 mas. Will the dimming be seen by eye or camera, and by how much ? The visual brightness of RY is a little uncertain (Im not a variable star observer).See Steve Preston’s IOTA prediction: https://asteroidoccultation.com/2024/2024_04/0424_19021_91308_Map.gif
Clear skies to all..
Tim
ARPS (Occultations)Attachments:
This sounds an intriguing event, Tim. Thanks for flagging it.
I’m not familiar with RY CrB, so I looked it up.
The Variable Star Index lists it as a semi-regular variable with a range 8.8 to 10.0 in V band. The period is ~90 days.There are no observations of it in the BAA VSS database. There are very few in AAVSO, the most recent being last August at 9.4 visual.
I wonder if the mag 6.7 you cite is an R mag. It is a red star of spectral type M8 to 10 so will appear bright at longer wavelengths as discussed in the R Lyr thread on the Forum.
Hi Jeremy,
Thanks for the comment. I’ve asked for clarification on the magnitude sources. The magnitude drop could be smaller than anticipated, owing to the “partial eclipse”. So a visual observer might not see any change – but without observing, we dont know. I video camera would be preferable to catch the drop.I observed from a carpark at Beacon Hill Hillfort just off the A34 South of Newbury. It was close to the mid-shadow line. Transparency was poor with thin cloud moving through but it was clear enough to see the pole star and the major constellations.
Equipped with a Vixen Polarie and WAT-910HX + 135mm F2.8 lens attached, i was able to find the target by star hopping. To do this I compared SkyMapPro and the video display. The occultation itself was not seen live on the monitor. When i got home, I analysed the AVI recording. There is a small brief dip at the predicted time. No fade was recorded.
It was more of challenge than i had expected, and i was pleased that the 50 mile drive from home resulted with a successful recording although no clear event.
I observed from a carpark at Beacon Hill Hillfort just off the A34 South of Newbury. It was close to the mid-shadow line. Transparency was poor with thin cloud moving through but it was clear enough to see the pole star and the major constellations.
Equipped with a Vixen Polarie and WAT-910HX + 135mm F2.8 lens attached, i was able to find the target by star hopping. To do this I compared SkyMapPro and the video display. The occultation itself was not seen live on the monitor. When i got home, I analysed the AVI recording. There is a small brief dip at the predicted time. No fade was recorded.
It was more of challenge than i had expected, and i was pleased that the 50 mile drive from home resulted with a successful recording although no clear event.
Hi Tim
Fine result.
I used to record asteroid occultations visually years ago but would like to try with a camera.
I have a Wat-908 (I think) somewhere and guess that it can be used.
Could you give some details of your setup and software?
Hi Lars,
Perhaps you have a WAT-902 ? Yes this could be used. My setup is:
Camera => GPSBOXSPRITE-3 (Time overlay) => Pinnacle Dazzle video digitizer (for W10/11) => Laptop with IOTA video capture.
Free software: IOTA capture, Tangra (Hristo Pavlov) for video analysis. (light curve and timed event).There are on-line sources for brighter predictions E.G. asteroidoccultations.com, but I use OccultWatcher (free software) which takes predictions from a server. I then filter them down to the ones near me.
Happy to help out.
My setup in 1991 with DIY video. Your WATEC would have the same sensitivity.
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Thank you. My camera is a WAT-902H2 ULTIMATE.
I got it used in a pile of equipment I bought some years ago. It came with a lot of cables, mostly with video plugs.
I have never used it, but there is a manual/fact sheet so I guess I could make it work.(Though I don’t like this sentence from the set-up section: Turn on the power to the WAT, the monitor and other equipment. When a strong smell of burning is present, or smoke is visible, turn off the power…)
HaHa. No observatory is complete without a fire extinguisher at the ready !
Yes the 902H Ultimate is sensitive but a bit noisy i believe. It will need a 12V DC supply and a phono cable ( also a BNC plug to phono maybe).
Ive not used one, but it may be possible to smooth out some noise when processing the video (Binning)
Feel free to contact the Section.Tim
Asteroids and Remote Planets Section (Occultations)
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