Nuts, I forgot to post about this earlier: tonight the Moon will pass in front of the bright star Antares. The time depends on where you are; the Moon is close enough to Earth that your longitude will change the timing of the event due to parallax. Check the Lunar Occultations site for info. Note that the time listed is Universal time! Go here to see what time that means for you.
This is a non-starter for me here in Boulder; the Moon will be below the horizon when it passes in front of Antares. But you may be in a better location!
Also cool: Antares is the brightest star in Scorpius (go here to get a sky map to see where to look) and it’s a red supergiant. It’s so freaking huge that it will take an appreciable amount of time for the Moon to cover it (a fraction of a second, but not instantaneous). If you’re in a place where you can see this, give it a shot! Binoculars are probably best for this, but if you have a small telescope that works too. Astroprof and AstroGuyz have more info, too.
June 6th, 2009 at 5:23 pm
Tanks Phil.
Assuming I’m interpreting all that correctly, that should be about 10:55 PM tonight, in other words, right after I get to work.
Good on Ya, Mate,,,
GAry 7
June 6th, 2009 at 5:23 pm
Here in Brasil (19 55 57 S. 46 56 32 O) the moon will pass close, very close to antares, but no occultation!
But I guess it will give a nice pic!
June 6th, 2009 at 6:13 pm
The Antarans are the blue guys with the antennae, right?
June 6th, 2009 at 6:17 pm
@Yossarian: No. That’s Andoria.
June 6th, 2009 at 6:18 pm
Darn. Well, it`s a moot point since we`re overcast here and I won`t be able to see `em anyways.
June 6th, 2009 at 6:20 pm
Camera ready? Check.
Telescope ready (to hook camera to)? Check.
Clear skies? Nope.
Cloudy and raining here in West Michigan. Too bad, as I was looking forward to this.
Oh well, I’ll have to live vicariously through other people’s images.
June 6th, 2009 at 6:29 pm
Phil, are you saying that the star is both close enough and large enough that it’s actually a reasonably large DISK ? I’ve looked it up, the star is 300M km in diameter, that’s a bit more than half a light-hour…. but the star is 600 light years away, about 10 million times its own diameter! I’ve got a hard time believing that the movement of the moon’s own disk (half a degree per hour with respect to the stars) will do anything less than instantaneously blink out the star. (But I acknowledge that you DID say it was a fraction of a second…).
June 6th, 2009 at 6:35 pm
Dang, a week’s warning would at least give people time to dust off bits and pieces and record the event with a UTC timestamp good to at least 10 microsec. Oh well, I’m too sick at the moment to do anything useful.
June 6th, 2009 at 6:45 pm
Here in Canada, as usual Toronto gets it again…
We won’t see it here in the Vancouver area… bummer
June 6th, 2009 at 6:52 pm
Phil, were you intending to provide a link to the sky map?
June 6th, 2009 at 7:32 pm
Wow, I’m amazed that you can only see it in certain latitudes, higher or lower and the Moon has shifted enough to not pass over Antares. I’ve never considered before that the Moon would be in different positions like that depending on latitude. Something else learnt!
The path stops just short of W Europe… what a pity we will miss out. My brain can’t quite grasp why that is the case right now, perhaps the Moon will have set by then. Though in much of the UK Antares doesn’t get very high – I’ve only positively seen it on a trip to the Canary Islands, and brilliant red jewel in the sky.
Imagine if you were just at the right latitude so that the star passed just at the edge of the Moon – as the light passed through the mountain ranges on the Moon, would it twinkle appreciably?
June 6th, 2009 at 7:35 pm
Meh. I don’t believe in the occult…
athankyou.
June 6th, 2009 at 7:37 pm
@ Michael L,
[Rant]
It’s the same here in London, UK; every time something interesting is going to occur in the night sky, it bloody clouds over — lousy god!
Furthermore, on the few occasions when the sky is clear, the goddamn neighbour leaves his 500 watt halogen floodlight on all bloody night in his back garden — the lousy bastard!
[/Rant]
June 6th, 2009 at 7:41 pm
@Pierre:
Dave Dunham of IOTA and JHUAPL says this regarding the graze:
“Most of the events during the graze will appear gradual, due to the 0.03″ angular size of Antares; even with a small telescope, you’ll be able to directly observe the effects of the red giant star’s size.”
So you will notice it gradually winking out. Might just be a split second, though. This is a rareish event, though, to be able to detect visually the disk of a star!
A grazing occultation occurs when the Moon just nicks the star and the star winks on and off repeatedly as mountains on the limb of the Moon get alternately in front of and uncover the star.
Any of you folks who like this stuff (and asteroid occultations too) should join the IOTA and do some real science!
http://www.occultations.org/
http://www.asteroidoccultation.com/
Stoney:
You don’t need a sky map, just look for the Moon, it’s hard to miss!
June 6th, 2009 at 8:09 pm
#14. Richard Drumm:
Don’t forget, Mars is the size of the full moon, so it could be confusing to some people…
June 6th, 2009 at 9:33 pm
@Richard: thanks. A quick back-of-the-envelope calculation reveals that, if the size of Antares is really 0.03 arcsec, then the disk of the moon would cover the disk of Antares in about 6/100 th of a second (for a full on ‘collision’, a grazing would of course extend that quite a bit).
Interestingly, Hubble (at least one of its instruments) has a resolution of only 0.1 arcsec, three times too low to resolve the disk of Antares.
June 6th, 2009 at 9:43 pm
Just popped outside to try to see it, and the “partly cloudy this evening” is of course covering that part of the sky. Drat.
June 6th, 2009 at 9:54 pm
I saw it, but I couldn’t find the tripod bracket for my 15×70 Celestron SkyMaster binocs. My wife had absconded with them for birdwatching and it looks like the bracket might have gone walkabout. So my hands couldn’t hold them still at all, even with a good prop. Should’ve gotten out the Orion dob… Oh well. There’s a good occultation of the Pleiades coming up, stay tuned!
June 6th, 2009 at 10:19 pm
I won’t be able to see this. Sigh.
June 6th, 2009 at 10:31 pm
Here in metropolitan Boston, the Moon is obscured, albeit not quite occulted, by the great nebula M0.
June 6th, 2009 at 11:27 pm
News flash! Phil Plait admits that astronomy is “occult”.
June 7th, 2009 at 12:36 am
In Vancouver, BC, the moon is red! It is absolutely amazing. Moon was fully red at about 11:05pm tonight. I did not know this was going to happen tonight, the moon fully caught my attention…stunning. I feel lucky to have seen it.
June 7th, 2009 at 12:45 am
Yup, saw it no problem here in Boston (Brookline, MA, to be more precise). Too bad we were just a tad too north to see Antares actually occulted, but the conjunction was spectacular enough
June 7th, 2009 at 2:49 am
Awesome! We saw it while on our moonlight pub-crawl (pub-peddle?) from Santa Rosa to Sebastopol. We thought it was Mars. Antares . . . who knew?
June 7th, 2009 at 5:29 am
Thanks for the shout out; we actually had clear skies here in Florida to view the occultation after weeks of rain; I caught the ingress on video and posted it on our Youtube companion site;
http://www.youtube.com/watch?v=3IrLdOqDcK0
Antares disappeared very quickly; didn’t manage to spot Anatares B. Of course, there was that nearly Full Moon thing…
June 7th, 2009 at 6:35 am
I know gravitational lensing was observable during a Solar eclipse which verified Einstein’s general relativity…. Curious Phil or any other Boltzmann Brain… Would the gravitation effects of the Moon on the light from Antares be sufficient to cause an observable blip in Antares position as it passes by the Moon in a fraction of a second?
If so, would it help if I “put down the ducky” ?
June 7th, 2009 at 7:27 am
Naked Bunny @ #21:
You mean Phil has turned to the occult!?
Now that’s more like it.
Addendum: Argh!! I really have no idea whether or not the occultation can be seen from where I live. Although, when I looked up to the sky, I was quite dismayed to find out that it was smoggy and there were no visible stars save for one or two very tiny dots. Even the moon, in its bright roundness, appears hazy.
June 7th, 2009 at 8:07 am
Oh, booger. I was all set up to watch it, and then the clouds rolled in. And this one was perfectly set up for where I live!
Ah well.
June 7th, 2009 at 8:17 am
When I read your post last night, it was one hour too late… =/
I was reading about Antares this week, and just how gigantic it is. It’s hard to believe something that big can even exist! The Universe is an amazing place.
June 7th, 2009 at 12:10 pm
13. IVAN3MAN
Ever hear of a pellet gun???
Overcast? Does that mean Y’All will be the last to see the GRB???
Dang! Sky was just enough overcast to wash out Antares. Bummer, but the moon was gorgeous.
GAry 7
June 7th, 2009 at 1:21 pm
For those who missed the event you can always use the free-ware program Stellarium http://www.stellarium.org/ to recreate the event on your computer screen. I’ve been using it since Fraser and Pamela at Astrocast mentioned it, and it really is a remarkable and easy to use program. You can also download the dimmer stars too if you’re of the mind to go star hopping with your telescope and want a guide.
Don’t stop at recreating the Moon-Antares event, but go back to about 2 BC, center on Regulus (click your mouse on it…if it drifts out of the field, hit the space bar and it’ll then stay centered while everything moves past it). Then fast forward to watch Jupiter do a retrograde loop around Regulus, and pass very close to Venus around 1 BC (was this a possible inspiration for the star of Bethlehem? Regulus and Jupiter both refer to king or a king, and the constellation Leo was the symbol of the tribe of Judah…????…astrologers may have interpreted that as a kingly event happening in the land of the tribe of Judah???).
Anyway, it is a lot of fun recreating past skies (check your birthday, see if those astrologers have the sun, moon, planets in the right position), predicting future conjunctions, and looking at the skies from another geographical location as well as just using it to navigate the skies that night (I think it even has a red “filter” so you can use it and keep your eyes dark adapted).
[I am in no way affiliated with the Stellarium program..I'm just an enthusiastic user].
June 7th, 2009 at 5:01 pm
r: tonight the Moon will….
\Please: tonight? GIVE THE DATE.
June 7th, 2009 at 7:00 pm
Look at you skeptics. So eager to bash the Occult when it upsets you, but happy to promote it when the Moon uses it to hide Antares.
June 7th, 2009 at 10:31 pm
In Denver, so I couldn’t see the occultation any better than you. But we did see a fabulous fullmoonrise on the way home from watching the movie “Up”.
June 8th, 2009 at 6:29 am
FYI :
“The Red Supergiant star Antares has a diameter over 1 billion kilometres compared with our Sun’s diameter of 1.4 million kilometres. If it replaced our Sun, Antare’s surface would be located well beyond the orbit of Mars.”
- Neil English, Pages 72-73, “A Summer Sizzler” in ‘Astronomy Now’ magazine July 2007.
For more info. on Antares it is also worth checking out this link to ‘Kaler’s Stars’ page on it :
http://www.astro.illinois.edu/~jkaler/sow/antares.html
PS. Sadly I missed the occultation – not visible from my location and cloudy too.
June 8th, 2009 at 10:37 pm
Argh! The table says 11:34 PM for my location, I checked it at 11:35PM!
June 9th, 2009 at 11:05 am
@Lawyer(#26): It looks like gravitational lensing by the Moon is beyond our current capabilities to detect.
At the Moon’s surface, I’m calculating a shift of 13 microarcseconds in position, compared to Antares’ diameter of 34,000 microarcseconds. The maximum resolution of the VLBA (the highest resolution of any current telescope AFAIK) is 170 microarcseconds, so we would need an order of magnitude improvement to have any chance of detecting a shift due to the Moon. And to do that, you need baselines so long that the occultation itself is not at all simultaneous.
However, it would be possible for SIM PlanetQuest, if it were ever launched — they claim an astrometric accuracy of 1.2 microarcseconds, so they should be able to get a 10-sigma detection of this shift. If they were ever launched.
June 11th, 2009 at 11:50 pm
http://www.youtube.com/watch?v=NWCAkmq8fho
I viewed on 6th June 2009 in Vancouver, Canada
above is the link to the video clip