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DaveGee
01-11-2018, 08:42 AM
47 Aglaja will occult a mag. 12 star UCAC4 361-202479 at around 10:30 UT (9:30 daylight savings time) on Saturday 3 rd November. See...
http://www.asteroidoccultation.com/2018_11/1103_47_57040_MapAU.gif

Currently there are 6 stations announced on Occult Watcher, but we are clustered on the east side of the path - see image.

We need help to cover the western side.:welcome:

The more the merrier!:rofl:

Imme
01-11-2018, 09:20 AM
Hi Dave,
Interested to hear what you need?
Is it photographic or video coverage?

DaveGee
01-11-2018, 12:35 PM
Hi Jon,

The goal is to observe and determine the time (in Universal Time), the instant the star disappears and reappears.

This can be done;
- visually using something like the timethesat app. available for android smartphones from the Google store. It's free. There are other apps for iPhones but I know... nnnothing!
- using video. The idea is to take images of the target star as fast as your equipment allows.

PAL usually runs @ 25 frames per second and if you can get your hands on a video time inserter like the old KIWI-OSD or IOTA-VTI then if should be easy to determine the time of the frame where the star disappeared or reappeared.

Determining frame timing of other types of video, like DSLRs with accuracy can be a challenge. There is an app. called Occult Flash Tag that can be used to flash the video at the minute mark and count frames from that reference to determine the times.

You'll need to know the geographic coordinates of your site to complete the observation.

Wavytone
01-11-2018, 04:17 PM
For iOS there’s AstroFlashTimer and not much else.

Don’t rely on the iOS clock time - it’s often off by seconds. If you want an accurate clock use Emerald Chronometer or their Observatory (iPads) these sync to NTP to milliseconds.

What I don’t know is whether the developer of AstroFlashTimer is aware the iOS clock is not accurate over the short term.

If nothing else you could use the i41CX emulator (it’s a programmable calculator with clock) and program this to issue a short audible beep (0.1s) every 5 seconds. Only snag for some will be the instruction set which is RPN and opaque to youngsters.

DaveGee
01-11-2018, 08:16 PM
Hi Wavytone (Nick) BigBanger,

Ditto for the PeeCee Windoze clock, neither is good for absolute time accuracy, but probably good enough to time the duration. Just get the cadence as fast as you can to "only just" see the star and keep the dead (download) time is small as possible and if that means choosing a small ROI then who's to complain.

Observe more worry less.:thumbsup:

P.S. No, I don't have a Russian under my bed, however I work with one - Nice chap.

tonybarry
03-11-2018, 10:45 PM
Looks like cloud all round for Aglaja. Oh well. Next time.

Regards,
Tony Barry
WSAAG