Grazing occultation 28-29 June

[AstralTraveller]

There is a grazing occultation occurring the weekend after next which some of you may be interested in observing and timing. The details are: 28th June, actually (Sunday morning 29th 4:56am) mag. 6.5 star grazing 15 degrees from the cusp, -25% moon at alt24 az43, northern limb. It should be visible in any scope >=10cm.

So it's easily observed but at an inconvenient hour; at least it is on a weekend. The path crosses the coast near Cape Otway, passes south of Geelong, through Melbourne, over Bright, over southern Canberra and crosses out to sea at Long Bay Gaol. It will be observed from Sydney and Canberra but, so far, there are no observers from Melbourne. Somehow I've drawn the short straw and will be organising the Sydney end (with a little help from some friends). The observing location will be either the Woronora Dam Rd or in the Royal NP a few km past Audley. .

Please let me know if you are interested. If you are interested but don't know what this is about please contact me anyway and we can have a chat.

cheers,
David

[bojan]

I am interested :-) (but not committed yet... and of course it all depends more on the Melbourne weather...)
Bojan

Edit:

According to CdC, for Melbourne there will be no occultation... or just...

[DaveGee]

Hi Bojan,

The star and moon will be at 17degrees altitude if observed from Melbourne.

Attached is to profile of the lunar limb for Melbourne's longitude. The blue dashed line is the Watts profile and the red and green dots represent historic observations. red are disappearances green are reappearances. As you can see, to get a chance of observing at least 4 events you want to observe somewhere around 1.5 to 2km south of the smooth profile line.

Here is an interactive Google map...
http://users.tpg.com.au/users/daveg/occ_maps/080628_ZC329.htm

adjust the range to -1.5km and -2.0km and zoom in to find a site between the grey lines.

[bojan]

Well, my backyard is 500 metres inside the grey lines. So I do not need to go anywhere. The only potential problem will be weather and possibly some power lines (and public lighting, of course.. one mercury bulb is right in the direction of Moon, seen from my favourite observing site...).
Hope for the clear skies...

edit:
Actually now I see it is not so simple, I will have to go Ashburton park, it seems.
Well, OK, so be it.. it is still couple of km from my home, acceptably comfortable, as long as weather holds..

[bojan]

Sorry guys.. it was cloudy in Melbourne...:sadeyes:
Dave, I would be very happy to know how it went elsewhere and of course, I would like to see the results of data processing (updated profile?)

[Rob_K]

Same here unfortunately, after a big window of clear sky late in the evening.

Cheers -

[AstralTraveller]

The graze this morning was a fair success. Observers in Melbourne, Bright and Canberra were clouded out. I've yet to hear from the bloke at Bungonia but I suspect he also had cloud.

Fortunately the Sydney group had good weather. Prior to the event the only bit of cloud was over the moon but even it was wispy and perhaps we would have got results through it (thin cloud isn't necessarily terminal - one can often still see the star). Unfortunately some observers battled with the trees (mea culpa, I didn't do a pre-graze reconnaissance and just relied on google earth images).

We had nine observers, 5 video and 4 visual. One of the video observers had equipment problems and so got no results (it happens to the best of us) but the rest had a great time. I had 9 events (including a 'flash'), another observer has reported timings for 10 events, one video observer had 6 and another 10-12 etc. I reckon we will total 60-70 events. I'll post the results when they are all in, however the data coordinator is leaving for a two week cruise on Tuesday so it may be a while.

As the graze was at 5am, we were packed up by about 5.30 and it was breakfast time. I took a portable BBQ and we retired to the picnic area at Audley for a dawn BBQ. This was the first time I have cooked a BBQ by torchlight!! By the time the food was ready it was light enough to see. We were early enough to avoid the feathered tourist-peckers and found they arrived in the order: wood ducks, magpies and then kookaburras. Everyone else was gone by 7.30 but I hung around for a bit and was rewarded with a sighting of an azure kingfisher.

Some days this hobby rocks!

[Rob_K]

Thanks David for that report, only sorry I wasn't able to contribute! :thumbsup: Look forward to the results!

Cheers -