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photonovore
Moonatic
Reged: 12/24/04
Posts: 2792
Loc: tacoma wa
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Tomorrow evening there will be an opportunity to observe Antares' last occultation event until 2009 (for most of North America anyway) and in parts of the country it will be a grazing occultation, skipping across the mountains & valleys, blinking in and out of sight. Kinda neat to see if you can catch it in exactly the right place (within a mile wide band or so). Details here.
I plan on taking my little ETX-70 porta scope for a view from a location where the grazing event should be visible...or so IOTA tells me. Anyone else in position to catch this event or perhaps do a timing??
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Mardi
4" achromat, ETX-70, 8"cat.
Whitepeak Lunar Observatory Website
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Anonymous
Unregistered
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If your are observing a near graze, be sure to see if you can detect a gradual fade out as opposed to an instantaneous disappearance. This arises from the large apparent disc size of Antares (about 0.040"). The fade could take as long as 1/4 second. I will also be observing, but it will not be a near graze here. I would be interested in hearing of your experience tonight.
Harrison
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jwaldo
Smart Mime
Reged: 04/26/04
Posts: 3836
Loc: Simi Valley, CA
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Any chance of seeing the second star while Antares itself is hidden behind the Moon this time?
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-R.J.
Discovery DHQ 8"
Celestron C4-R on LXD75
ZenithStar 66 ED Triplet
Hardin DSH 6"
Orion Transporter 70
Sears 60/900mm
10x50's & assorted other binos
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Anonymous
Unregistered
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Theoretically, yes. However, since the 5th magnitude secondary lies almodst due west of the primary, it will disappear first. On emersion, it will reappear first, but this will be against the bright limb, and the chances of seeing it then would be practically nil. The best chance of seeing it at all would be if you are near the graze path with multiple disappearances/reappearances of both stars against a dark limb.
Harrison
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jwaldo
Smart Mime
Reged: 04/26/04
Posts: 3836
Loc: Simi Valley, CA
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Well, I missed it. I ran out, pointed the scope at the moon, and there was Antares, sitting RIGHT ON THE VERY *BLEEEEEP* EDGE OF THE MOON! MISSED IT BY SECONDS!!  
EDIT: Or did I? I was looking at the wrong star...
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-R.J.
Discovery DHQ 8"
Celestron C4-R on LXD75
ZenithStar 66 ED Triplet
Hardin DSH 6"
Orion Transporter 70
Sears 60/900mm
10x50's & assorted other binos
Edited by jwaldo (07/18/05 12:11 AM)
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jwaldo
Smart Mime
Reged: 04/26/04
Posts: 3836
Loc: Simi Valley, CA
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Yeah, I missed it. I am so stupid... 
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-R.J.
Discovery DHQ 8"
Celestron C4-R on LXD75
ZenithStar 66 ED Triplet
Hardin DSH 6"
Orion Transporter 70
Sears 60/900mm
10x50's & assorted other binos
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jwaldo
Smart Mime
Reged: 04/26/04
Posts: 3836
Loc: Simi Valley, CA
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Well, this story has a good/bad ending.
Good: I FINALLY SPLIT ANTARES!!!!1!! 
Bad: I've finally realized I NEED to have my mirror recoated. The whole sky around the Moon was just as bright as the Moon itself. I looked into the focuser to see the source of the glare, and it was the white gunk on both mirrors. The same stuff that makes my mirror about 75% reflective. Recoat time!
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-R.J.
Discovery DHQ 8"
Celestron C4-R on LXD75
ZenithStar 66 ED Triplet
Hardin DSH 6"
Orion Transporter 70
Sears 60/900mm
10x50's & assorted other binos
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microbes
Pooh-Bah
Reged: 12/12/04
Posts: 1217
Loc: Romulus, Sector 12
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I didn't know ahead of time that this was going to happen, but I saw the star close to the moon earlier and I could just tell it was going to. I wasn't sure of the timing, so I glued my self to the scope til the star disappeared, and now if I'm right I have a maybe 15 or 20 minutes until it comes back. Headed back out.
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Dirt Cheap Astronomy
Voyager 114X900 Newt EQ2 * Sky Chief 60X700 EQ1 * Cometron 62X300 EQ1
Sears Ultra Wide 7X50 Binos * Vintage 16X50 Binos EQ1
Books, Barlows, Eyepieces, Camera Adaptors & Other Esoteric Junk.
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photonovore
Moonatic
Reged: 12/24/04
Posts: 2792
Loc: tacoma wa
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well, just got back from the little excursion to observe this. Strapped the etx-70 on the back of the dual sport and way we went. Got a nice spot about 20:15 and set up. 20:34PDT right on schedule Antares faded more than 'blinked' away IMO; i was using a barlowed 9mm gso, about 77X. Maybe a 1/4 second of dimming/flicker? I'm not sure but it didn't just blink out all at once like other ordinary occultations i've observed. Then at about 20:36 it came back into view, but I didn't catch it as some passerby picked that very moment to ask what I was doing! ("Occultation?!? But I don't see any star!?") argh. Murphy's law. I continued watching and shortly Antares started dimming once again and *almost* dissappeared but not quite. It was sure close though. It got to the tiniest pinpoint of light and appeared to sort of twinkle furiously for a long bit; there was a bit of scintillation as the moon was less than 15 degrees above the horizon but that didn't account for all the brightness variations i saw. This seemed to last maybe a minute or so altogether and then it regained full brightness and that was that. I watched until about 20:40 or so, just in case, but it was obvious by then that the event was over.
This was a far thing from any sort of 'timing operation' obviously, all I brought along was the cell phone for the time and it reads only to whole minutes. This was my first grazing occultation, so I was more interested in just watching it than getting all 'amateurs do science' on it...this time anyway. 
I was about 1-3/4 miles south of the northern limit line, which was supposed to be ideal, however obviously another 1/4 mile to the south would have completed the second occultation. It's obviously a *very* narrow band for ideally observing something like this. Earlier I stopped by a guy who had a small scope setup and he was part of an IOTA timing group, about six of them spread out from a mile down to 2-1/2 miles or so south of the limit line i think--he showed me a map but i don't recall. It will be interesting to see what their results were, they should be posted on the IOTA site sometime soon I imagine. Pretty cool event though, glad I took the time to go see it. 
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Mardi
4" achromat, ETX-70, 8"cat.
Whitepeak Lunar Observatory Website
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Tommy5
Carpal Tunnel
Reged: 03/28/04
Posts: 2523
Loc: Chicagoland
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In Chicago,Antares missed the moon by quite abit, here is a photo i took of the non-event 6" achro, 3.2 Fuji handheld,sounds like some of you other guys {and girls}had a fun time. 
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microbes
Pooh-Bah
Reged: 12/12/04
Posts: 1217
Loc: Romulus, Sector 12
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Quote:
I didn't know ahead of time that this was going to happen, but I saw the star close to the moon earlier and I could just tell it was going to. I wasn't sure of the timing, so I glued my self to the scope til the star disappeared, and now if I'm right I have a maybe 15 or 20 minutes until it comes back. Headed back out.
This one took me by surprise, but looking at the charts linked to in the op, it lasted about 45 minutes for me. It took a little longer to come back than I thought (I'm about half way between Tampa and Gainesville), and I missed the exact time it reappeared  . When it disappeared it didn't fade, twinkle, or anything like that, it just blinked out, but a 45 minute occulation (at my location) isn't quite "grazing". It was however, quite interesting to watch considering that last night was the first time in 10 days the sky was clear enough to see anything at all, and that between the moon, and the haze, and poor seeing "anything" was only shimmering views of brighter objects. It made what normally would have been poor night of lunar viewing into something a little exciting.
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Dirt Cheap Astronomy
Voyager 114X900 Newt EQ2 * Sky Chief 60X700 EQ1 * Cometron 62X300 EQ1
Sears Ultra Wide 7X50 Binos * Vintage 16X50 Binos EQ1
Books, Barlows, Eyepieces, Camera Adaptors & Other Esoteric Junk.
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typhus
professor emeritus
Reged: 11/06/04
Posts: 669
Loc: Tucson, AZ
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I was waiting all month to see this. The skies have been clear for months, but last night it was cloudy and raining. I'm not complaining too much, we actually need it here. I'm glad everyone enjoyed the show.
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Shane
Orion XT10i
10x50 Binoculars
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hoof
Carpal Tunnel
Reged: 04/07/05
Posts: 1523
Loc: Redmond, WA
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Yup, cloudy here too. The Moon was "visible" as a whitish glow about an hour before, but was completely hidden during the event. You could say that both the Moon and Antares were "occulted" by the clouds
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Jonathan Hoof
15" F/4.14 Discovery Truss
8" F/5.9 Orion XT8i
6" F/6 Intes-Micro MN66
127mm F/7.5 Meade APO
80mm F/7.5 Orion 80ED
18x50 IS Canon binoculars
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Anonymous
Unregistered
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I had a beautiful view of the occultation. Immersion occurred here at about 20:13:10 PDT, only eight minutes after official sunset. Nevertheless Antares was big and bright in my 6" refractor at 48x. There was little twinkling sine it was already up 26° in the southeast at immersion and 29° at emersion which occurred at about 21:08:16 PDT. There was indeed a slight but perceptible fade upon disappearance, much like an icandescent light when it is turned off.
The timings I quoted above are from a computer program I developed for occultation predictions. It uses about 6000 trigonometric terms for the motion of the moon itself and is very accurate. Using this program I found that we will not be seeing any more Antares occultations until 2023 (except for a couple of very unfavorable daytime occultations in 2009). There will be a series of Regulus occultations in 2007.
Harrison
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