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[Centaur]

The 92% illuminated waning gibbous Moon will occult magnitude +2.9 Mu Geminorum for observers in most of North America during the early morning of 2010 NOV 24. The southern graze path will pass through Northern California and then into the southwestern states. The northern graze path will be in the arctic region.

Observers on a graze path will be able to witness the star winking on and off as lunar hills and valleys pass by. Those between the graze paths will see a full occultation. Immersion will occur on the lunar bright limb, while emersion will come from the dark limb. The star’s apparent equatorial coordinates at the time of the event will be RA 06:23:39.7 and Dec N 22°30’25”.

I’ve created a North American graze map; also a preview graphic with data for observers at Chicago’s Adler Planetarium. They can be seen by clicking www.curtrenz.com/astronomical and then going to the Moon page.

Photos and descriptions of the event would be welcome additions to this thread. If you would like occultation or graze data specifically for your location, then please reply to this post with a longitude, latitude, time zone and altitude above sea level.

[patrickm]

Hiya Centaur,
I will be in Austin at the time. Will that significantly affect my view? Guess I could just check SkyVoyager, but it's been so cloudy, and so quiet around here lately I thought I might try to stir a teensy bit of discussion.
Thanks,
p

[patrickm]

From your graze map, looks like I'll be just on the edge of the graze path but should still have full occultation.

SkyVoyager tells me that we are on the graze path, and that if we get a full occultation in Austin that it will only be for a very few minutes. Photo attached.


Not sure if I can drag my butt out of bed for this one, and won't have an SLR for photos, so documenting would be crude anyway. We shall see.

Thanks for posting. If not this one, I'll catch one someday.
p

[Centaur]

Patrick, based on the coordinates for Austin in Wikipedia, you are indeed not far north of the southern graze path. I predict immersion at 06:02:57 CST and emersion at 06:26:14 CST.

[Centaur]

2011 will be an unusually poor year for lunar occultations of planets and first magnitude stars. There will be only three: all involving planets and none visible from North America. In 2010 we’ll have an occultation of Mars visible from North America on December 6. This will be an afternoon event for western observers and an early evening event for those along a small strip slicing north-south through the middle of the continent including Chicagoland. Interestingly, during the total lunar eclipse of December 20/21 the Moon will occult the asteroid 348 May and the open cluster NGC 2129. Next month on my website I’ll post preview graphics and data for these events. Meanwhile, I’ve created a preview animation of the eclipse: www.curtrenz.com/astronomical

[patrickm]

Ooh! A cliffhanger!!! I love suspense.
;D

[Paulie pchris00]

I'm getting ready to observe this now. The telescopes are outside acclimating, and my pot of coffee is ready. My only concern is that Accuweather's satellite is showing cloud cover moving into the area, thouh right now it's only patchy clouds. It's a big system, no rain though, and there is an eye opening up as it crosses into Illinois, and it's currnet path should bring it over Valpo before emersion. The immersion, however, will almost definitely occur before before this opening arrives. At this moment, the Moon and brighter stars are visble, the clouds acting more like haze or slight fog than anything else, even though the edge of the system has crossed all of Indiana. Central and southern Illinois are in the heart fo the system, but it looks like for the Chicago area and Northwest Indiana, we will at see portions of the occultation this morning. The current temperature is 21 F, with the 6 mph WSW breeze bringing the wind chill to 16 degrees. Brrr....

For Patrick down in Texas, the only major clouds I see on the satellite are along the Oklahoma border, and another line crossing over the Dallas/Ft. Worth area, so the only thing holding you back this morning will be motivation. I know I might not feel like getting out of bed for this if I wasn't normally awake at this hour anyway.

I almost forgot, but I am using the following website for my timings, if possible:

www.time.gov/timezone.cgi?Central/d/-6/java

It is two seconds behind the time on the Moon phase gadget on my blog, which itself is only about one second ahead of my computer, and three seconds faster than my phone, but I want to be as accurate as possible.

[Paulie pchris00]

Totally clouded out for the immersion, and worse, the break in the system is filling with clouds, and the heart of the system is moving farther north than it appeared to be heading at first. Had a look through the telescope at 5:17 AM CST, while ony a haze covered the Moon, but Mu Geminorum was not visible.

[Chicago Astronomer - Astro Joe]

Chicago clouded over.

[Paulie pchris00]

Unsuccessful. Full story soon.

[patrickm]

Clouded over here.

But it's in the 80's so shan't complain. Cold front tomorrow should blow this junk outta here and maybe some astronomy Friday...

Wish I'd seen this. Would have been really cool along the edge. Oh well. Thanks for trying, Curt.

Somebody around here needs to get us an in with Tommy Skilling so maybe he can do something for us.

[Centaur]

Sorry that the sky gods weren’t smiling on you occultation hopefuls this morning. I’ve now made more graphics available on my Moon page. December New Moon spotting will occur during an occultation of Mars. In addition to the usual western sky graphic, I’ve created a Mars graze map for North America and occultation info for Adler observers. The December total lunar eclipse will occur during occultations of an asteroid and an open cluster. I’ve made an eclipse panorama and animation, and graze maps for the occultations. After the Mars occultation is history, I’ll post Adler specific data for the occultations that occur during the eclipse. Click www.curtrenz.com/astronomical and then go to the Moon Page.

[Paulie pchris00]

I’d been looking forward to Wednesday morning’s lunar occultation of Mu Geminorum almost since the last time it was occulted on October 27. Weather hadn’t cooperated with me well for that occasion, but I was able to catch sight of the star not long after it emerged from behind the lunar disk. I fought a strong, cold breeze and scattered cloud cover that night. I was disappointed not to see the immersion point of the occultation, and hoped that my rematch on November 24 would be better.


There was really no preparation needed to observe the occultation, other than to review the event times posted by Curt, although since they are calculated for the Adler, they wouldn’t be accurate times for me at home, but are close enough to tell me when to pay attention. Curt’s listed time for the immersion was 5:24 AM Central Standard Time, and 6:34 for the emersion, just 16 minutes before sunrise. Being at the eastern edge of the Central Time Zone, the emersion would happen during morning twilight, so I wasn’t sure if I’d be able to observe it. It was worth a try though.

I skipped a clear evening sky Tuesday night to sleep, planning to get up and observe in the middle of the night. I woke up around 2:30 AM, and checked the radar and satellite images before getting out of bed. A system was moving in, but there was a chance it might stay just south of Valparaiso. Getting up to have a look out the back door, I was glad to walk into the dark kitchen and see a bright rectangular spot on the floor. The Moon was shining down at an angle through the skylight.

I got bundled up, went outside and set the telescopes up to acclimate to the cold. I wasn’t in much of a hurry, except to get back inside and out of the 21 degree temperature, and16 degree wind chill factor. I did admire a nice full 22 degree halo around the Moon, though. After getting the telescopes ready I went inside to make a pot of coffee and check the latest weather satellite images. It wasn’t looking good, really. I was concerned that Accuweather's satellite showed cloud cover moving into the area, although at that time it was only patchy clouds. It was a big system, but no rain, so I didn’t have to worry about the telescopes outside unattended. The weather system I was watching had an eye opening up as it crossed into Illinois, and it's path could have brought that clear spot over Valpo before emersion. The immersion, however, was almost definitely going to occur before the opening arrived.




Around 3:30 AM CST, the Moon had a gorgeous halo, but of course it doesn't show in the picture.


Just after 4 AM, the Moon and brighter stars were still visible. Even though the edge of the system had crossed all of Indiana, the clouds were acting more like haze or a slight fog than anything else. Central and southern Illinois were in the heart of the system, but it looked like the Chicago area and Northwest Indiana, would see portions of the occultation.





I was trying to stay out of the cold as much as possible, so I didn’t try to observe the Moon as it caught up to Mu Geminorum. In hindsight, I should have. By the time I was ready to face the cold around 5AM, the sky was completely clouding over. All the bright stars had disappeared, and the Moon was barely visible through them. I kept a vigil on the tracking of my go-to Newtonian, so that if sucker holes opened up, I would be able to take advantage immediately. Of course there were no sucker holes, but at 5:17 AM, only a thin haze covered the Moon. I looked just in case, since the occultation was to begin in about 7 minutes, but the haze was too thick for the starlight to shine through.




The Moon shrouded at 5:36 AM.


I missed the immersion, but stayed out in the cold hoping that I could observe the emersion around 6:34. I was constantly checking Accuweather for an update on the system moving through, but they did not update the satellite images after 5:32. I watched the clouds pass over the Moon, which also kept the wind at my back. Turning around, though, by 5:35 I noticed the clouds in the east turning a deep red hue, portending daylight’s imminent arrival, with still nearly an hour to go before Mu Geminorum would emerge.








Daybreak.


By 6:30, though hidden by clouds, the Sun had been up almost forty minutes. I started observations again, however unlikely I would get decent results. The clearing in the system that I was waiting for had started closing as it crossed Illinois, and the entire front shifted north, socking in Valparaiso. We were out of the worst of it, teasing me with the Moon showing through the haze. In a way that was worse than being totally clouded out. I wasn’t going to give up when my target was still (sorta) visible. At 6:35, after Mu Geminorum should have emerged, the clouds eased up slightly, but not enough to reveal the star. After that it only got worse. The sky was getting too bright, my toes were totally frozen, and when I looked up at 6:40, the Moon had disappeared behind the clouds. It was time to pack it in and admit defeat.




6:30:15 AM CST.








6:34:27 AM CST.



6:35:20 AM CST. This was the clearest point of the observation.












By 6:40 the Moon was totally obscurred.


So, given that the observation was unsuccessful, why go through the trouble of such a lengthy post? Mostly to prove that I didn’t sleep through it!

[patrickm]

You win. I just checked the weather and stayed in bed.

You are intrepid!

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