Leonid Meteor Shower 2009

[horgar]

Hello everyone. Although I am new to the community here I was wondering if someone could help me out with a couple of questions.

I was wondering what would be a good day/time to try and catch the showers (it will be my first) if the peak is going to occur as estimated, Nov 17 @ 21:00-22:00 UT. I live in Orange County, California which i believe is an -8 hour time difference.

Also, if anyone is from the area, what would be a good place to try and watch them? Would anywhere with a sufficiently dark horizon suffice?

Thanks for your time and help. I greatly appreciate it.

Jack

 

[MeteorWayne]

Unfortunately, the main peak, and the modeling predicted outburst will occur during the daytime for the US. There are 5 minor enhancements above the normal 15 an hour ZHR expected, only one of whichis observable from the US in the early morning hours of the 17th with rates possibly as high as 30 per hour. The predicted highest rate of 150-200 per hours will be later in the middle of the afternoon.

As far as a location for watching, I might suggest contacting the Orange County Amateur Astronomers:

http://www.ocastronomers.org/

They have a meeting open to the general public Nov 13th, perhaps they have some suggested observing locations.

I'll be starting a detailed thread on the Leonids later today in the Space Science and Astronomy forum. (still writing)

 

[billslugg]

Since the peak activity occurs during daylight for us, why not set up any radio or TV on a channel with a distant station and see if you can observe snippets of programming via a "bounce" off the ionized trail? Plenty of info on the net about this. here for example.

 

[horgar]

Thank you for your responses. The information was extremely helpful and I plan to check out the OC Astronomers meeting to seek further information.

Cheers

 

[RichardG]

New Question:
Is the Crew of the ISS in any additional danger as we pass through the trailings of Comet Tempel-Tuttle?

With the number of meteors expected to be visible and the number that are too small to be seen, puts that number of meteoroids at an extremely large number. I would be afraid that one or two of significant size might collide with the ISS damaging it and possibly worse.

Are the odds in the crews favor?

Is there any extra precautions the crew can take, such as getting into a protected area during the event?

The ISS has obviously been through this and other comet trails before. Has there been any damage then?

 

[MeteorWayne]

Even during a peak shower rate of ZHR 200 like expected at this year's peak for the Leonids, there is onlly a particle an hour per cubic km per hour or less, so it is no more of a threat to the station than orbital debris, in fact far less.
As a precaution, they do not plan EVA's during such shower peaks due to the lesser protection that the EVA suit supplies. Most Leonid meteors are very small (smoke particle sized) but are travelling very fast (71 km/sec).

You would probably not want to be flying during the great Leonid storms of 1866 or 1966 (ZHR > 100,000), or even the lesser storms of 1999-2001( ZHR 3500-4000), but other than that, it's a nearly insignificant increase in risk to the ISS.

 

[matthewota]

I witnessed the 01 shower form the Orange County Astronomer's club site. However, any dark area will do. If you have the transportation and the will to do it, Cottonwood Campground in Joshua Tree National Forest is in a Bortle Blue zone and is quite dark.

 

[MeteorWayne]

See the 2009 Leonid thread in SS&A.

I suspect most casual observers will be sorely disappointed in the US this year.

 

[andrew_t1000]

Here is a great article I found on Environmental Graffiti, some beautiful images.

http://www.environmentalgraffiti.co...nvironmentalgraffiti+(Environmental+Graffiti)

 

[MeteorWayne]

The IMO's On-The Fly Leonid page has added a new category to the ZHR data page.


Particle density is the approximate number of particles causing meteors brighter than magnitude +6.5 per billion cubic kilometer (i.e., a cube with 1000 km edge length).

http://www.arm.ac.uk/~gba/imo/leonids2009/

 

[newlooker]

in what direction should i be lookin from south texas?

 

[Orion888]

hogar, a lot of people from Orange County have asked such a question...I think a lot of folks are heading over toward the Joshua Tree area to get out of the lights. Orange County has one of the largest astronomy clubs IN THE WORLD...I suggest for future purposes you hook up with them, they always have a lot of interesting activities....Don't forget a reclining lounge chair or your neck will be killing you the next day....Good Hunting...Your friend, Orion...

 

[MeteorWayne]

in what direction should i be lookin from south texas?

From my experience (which is extensive) the best direction is due east about midnight, shifting to southeast by dawn. You want to be far enough away from the radiant so the meteors are longer and easier to see. Generally, below Gemini, and about halfway between Leo and Orion. Don't look directly overhead, but about 60 degrees above the horizon; that lets you sample the most volume of the meteor layer.

In Texas, the Leonids are not visible at all before 11 PM, and the highest rates should be right before dawn.

Meteor Wayne

 

[snowy062]

I'm up on the North shore of Lake Superior. MeteorWayne,are my chances good of seeing some of the Leonid shower tonight, or tomorrow evening?
It's as clear as a bell out there,no lights getting in the way...just pretty chilly. What time would be optimal in this area for viewing? My Lat. is 48.783, Long. 87.100, Elev. 258 m. Thanx.

 

[MeteorWayne]

Sorry I didn't see your message, I was taking my pre observing nap. (To no avail, I was up from midnight till 5 AM watching the clouds ). This past morning (the morning of the 17th) was supposed to be the best for the US. There should be some activity tomorrow morning.

As far as the best time, for the Leonids it's always midninght till dawn, with the highest rates toward dawn as the radiant gets higher in the sky.

 

[crazyeddie]

I went out several times between midnight and 1:30 am Tuesday morning, and didn't see a single meteor. Annoyed and disappointed, was I! :evil:

 

[MeteorWayne]

Well, first of all, that's a little early for the best rates.

The other clue is you "went out several times between midnight and 1:30 AM". That's not how to watch meteor showers.
If you aren't going to spend at least an hour continuously, don't bother, because it's a crapshoot.

At that time, the reported ZHR was about 25. Since at that early hour, the radiant was only about 15 degrees above the horizon; that means that you would only see about 25% of the ZHR under perfectly dark (desert) skies...so that brings you down to 6 an hour. That 6 could occur in 5 minutes during the hour, or one every 10 minutes.

If you live under light polluted skies, the rate would be even lower.

So it's not surprising that you saw nothing in 10 or 15 total minutes under those conditions.

 

[MeteorWayne]

To follow up on the risk during the Shuttle mission, it appears that the maximum particle density for the 10 minutes near the peak was about 200 particles in a billion cubic km (A cube 1000 km on a side)

 

[crazyeddie]

Well, first of all, that's a little early for the best rates.

The other clue is you "went out several times between midnight and 1:30 AM". That's not how to watch meteor showers.
If you aren't going to spend at least an hour continuously, don't bother, because it's a crapshoot.

I spent about 10-15 minutes out each time. It was enough to know that it was not going to be a good display. I'm not used to staying up that late, and I couldn't get comfortable because I was on the sidewalk outside my condo complex. But it was a lovely, clear night, even from my light-polluted site....I could see stars almost down to the 4th magnitude, which is pretty good for the city.

Did anyone get to witness any bursts of activity?

 

[MeteorWayne]

If you can only see 4th magnitude stars, then your realistic Leonid rate at that time would be about 2 per hour, which explains why you did not see anything. The hourly rate would have been about 6 if you had LM +6.5 skies. With +4 skies, it's not good at all.

Perhaps you would have better luck with the Geminids in December; not only is the radiant higher earlier in the night, but the ratio of bright to dim meteors should be better, as well as the ZHR at that time would be far better (closer to 100).

Still don't understand why if you looked at the real science you were surprised to see nothing. With an hourly rate under your radiant elevation and sky conditions of 2 per hour.... I suspect like many astronomers, you don't really understand meteors

 

[crazyeddie]

If you can only see 4th magnitude stars, then your realistic Leonid rate at that time would be about 2 per hour, which explains why you did not see anything. The hourly rate would have been about 6 if you had LM +6.5 skies. With +4 skies, it's not good at all.

Perhaps you would have better luck with the Geminids in December; not only is the radiant higher earlier in the night, but the ratio of bright to dim meteors should be better, as well as the ZHR at that time would be far better (closer to 100).

Still don't understand why if you looked at the real science you were surprised to see nothing. With an hourly rate under your radiant elevation and sky conditions of 2 per hour.... I suspect like many astronomers, you don't really understand meteors

I guess I'm comparing it to the truly awesome display a number of years ago, when there were so many whizzing across the sky that I couldn't see them all. It must have spoiled me!

 

[MeteorWayne]

That spoiled all of us, eddie!!

 

[ZenGalacticore]

MW- When can we expect the next meteor shower-whichever one- that will coincide with a new moon and be optimal for N. America? (Obviously, I understand you can't give us the prediction of atmospheric weather conditions.)

 

[MeteorWayne]

That would be the Geminids, peaking around Dec 13/14th or so. The ZHR is ~ 120, so about 5 times higher than the NA Leonid rate; and the other plus is the radiant rises earlier, so you can watch in the near midnight time frame, instead of having to stay up till dawn for the best rates. Look for a post in Space Science in Astronomy about Dec 5th or so, just before the shower starts.

MW

 

[ZenGalacticore]

Thanks. And I take it that the Geminids coincide with a new moon, or at least a crescent?