2672 Pisek to occult mag. 4.1 star

[DaveGee]

On Saturday 4th August 17:32 to 17:43 UT (= Sunday morning 5th August) 2676 Pisek will occult th mag. 4.1 star.:eyepop:

Naked eye events like these seldom occur and observers along the shadow path between Cervantes, Port Augusta, Wollongong, New Plymouth and Napier may witness this special event.

The Occult prediction map can be seen here...
http://www.asteroidoccultation.com/2018_08/0804_2672_57670_Map.gif

We are after accurate disappearance and reappearance timings. There are a number of observation methods to choose.
- GPS+1pps time-stamped video.
- video "flashed" with Occult Flash Tag before and after the event
- visual with timestamps using an NTP phone app called TimetheSat
are a few options.

Interested?;)

[AstralTraveller]

Thanks for the heads up Dave!

LOTS of people have the chance to see this.

Even though the path is only 25km wide the prediction has a relatively low precision (32/100) and so all of southern Sydney is within the 1-sigma zone. In the attachment the predicted centre line is green, the path is blue and the bold and light red are the 1-sigma and 2-sigma zones. The mag 4.1 star is delta-Cetus and is at 44* elevation and 46* azimuth, about 10 degrees above a third-quarter moon. I think the latter may be an issue for visual observers under hazzy skies but should not be an issue for any sort of scope or bino.

I'll be using a video camera with time stamp but I imagine any sort of observation, visual or any form of recording might potentially be useful - even if timings are only of duration. It can all help map the size and shape of the asteroid. And who knows, someone off the main path may record a small secondary body - it's happened a few times before. People with video or CCDs may even find a dust ring, like the discovery recently reported in S&T.

I think that, for an astronomer, 3am on a Sunday morning is a perfectly civilised time so I hope for lots of interest. :)

[DaveGee]

Yes, it's not often you get a chance to measure a chord across an asteroid (in km) with your naked (unaided) eye, and out resolve Keck, VLT and Hubble (whatever) in the bargain.:rofl:

[OzEclipse]

The asteroid is probably bright enough to record with a DSLR video through a scope with a bit of aperture. The flash tag apps Dave referred to are both free and simple to use.

Two versions are available -

Astro Flash Timer for iPhone (free)
AstroFlashTimer provides precise timestamp flashes based on GPS timing from the camera LED for astronomical videos (primarily asteroidal occultation recordings). Just point the camera flash into the optical path of the video recording device and trigger the desired flash mode. The app will log the exact time of the video flash onto your iPhone. The timing information can then be sent from the iPhone by email or text for later analysis. It is available from the App Store or from here : -
https://sites.google.com/site/astroflashtimer/home

Occult Flash Tag for Android (free)
Occult Flash Tag provides precise timestamp flashes from the camera LED for astronomical videos (primarily asteroidal occultation recordings). Just point the camera flash into the optical path of the video recording device and trigger the desired flash mode. The app will log the exact time of the video flash onto your Android device. The timing information can then be sent from the Android phone by email or text for later analysis. It is available on Google Play - https://tinyurl.com/y8otw47b

So there is no reason not to have a time stamp on your video.

Joe

[noswonky]

I have announced a station in Occult Watcher. It says I'm 6km outside the 1-sigma zone with 7.6% probability. Not great chances but perhaps I'll record a useful 'miss' observation.

[Robh]

I might have a go visually with my refractor and use Emerald Timestamp on my iPhone. Easy star but the short occultation time will require lots of concentration!

[DaveGee]

Just a reality check. Attached is the station sort...
It might be 7.6% (or whatever) at home, but the probability rockets up to 18.4% standing on the centreline.

The message is:-
-Observe where you are and hope:shrug:
-travel if you want to but there is no guarantee:sadeyes:
-observe more worry less.:rofl:
-don't travel distances with any expectation:screwy:

Good luck to all.

[AstralTraveller]

Preparations proceed.


Last night I tested my video recording gear and IOTA time inserter and all went well. We also tested Occult Flash Tag that my mate will use and found how to get a flash without saturating the detector. My mate also got up at 3.30 to practice finding the star. However, from his place in Pt Kembla he couldn't even see the Pleiades! Luckily on Saturday he will be at his hobby farm in Bungonia (about 0.4 std dev south of the track) where light pollution and neighbour's trees are not an issue. There is also another observer in Keiraville ready to go too.

[OzEclipse]

Do share? Astro Flash Tag (iOS equivalent) has a brightness control. I also plan to have a small piece of dark grey or black card in a lower corner of the field. The flash will illuminate the low reflectance card.




He won't need the Pleides. The last 1/4 Moon is really close as is Alpha Cetus. easy star hop from the moon to HIP12387. He might need a decent lens hood.

cheers

Joe

[AstralTraveller]

Nothing fancy. He just stood to the side and aimed the flash at the inside of the dew cap. I suggested he does several from slightly different angles so hopefully one is usable.








I pointed that out to him and suggested he looks at the scene in Stellarium before the night. It turns out that he made an impromptu attempt subsequent to a call of nature.

[anthony.tony]

what Class of Asteroids can I find it in The Minor Planet Data Base

[OzEclipse]

Tony,

Not sure why you need to find the asteroid?

The star is naked eye at 4th magnitude.
The star is Delta Ceti or HIP12387.

Canowindra is just inside the 1 sigma error limit on the north side.

Good luck.

Joe

[anthony.tony]

Just want to load the elements into Stellarium.

[DaveGee]

a miss from Hawkesbury Heights.

to report your observations, positive or negative, please use the attached form... (in the .zip) and send it to Steve Kerr at mpobservations@occultations.org.nz

:thumbsup:

[AstralTraveller]

Also, no events seen from Tarrawanna and Bungonia. However the next bit of the learning curve is to process the videos in case there is something interesting that wasn't obvious.


[To paraphrase Led Zep. Where's the rock? Anyone seen that confounded rock?]

[OzEclipse]

Nothing from north of Yass.

Joe

[DaveGee]

The latest news I have, via Rob McNaught is that Steve Quirk observed a positive from his home observatory.:thumbsup: I don't know exactly where that is.

[theodog]

North of Mudgee.

[tonybarry]

Nothing from Werrington (near Penrith). In the 1-sigma anyway.

Regards, Tony Barry