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Delta Aquarids | Meteor Shower [July 28-29, 2007]

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posted on Jul, 28 2007 @ 03:48 AM
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Delta Aquarids
July 28-29, 2007

Frequency: 16-30 per hour
98.1% illumination

At peak time about 20 bright, yellow meteors can be observed per hour. Because these meteors nearly broadside the Earth, their speed is a moderate 25.5 miles per second.

SOURCE | TheSkyScrapers.org | Read more...



July 27 or 28, 2007 South Delta Aquarids
Like most meteor showers, the best observing for this shower is before dawn. Unlike most meteor showers, this one doesn’t have a very definite peak. Instead, it rambles along steadily in late July and early August. The July full moon comes on the 29th. So in late July, the moon will be filling the sky with its light. That’s bad news for the Delta Aquarids. This shower will be mostly drowned in bright moonlight this year, although you might see some meteors in the light of the moon in late July. But that same late July full moon is good news for this year’s August Perseid shower.

SOURCE | EarthSky.org | Read more...



Sky-Watcher Alert: Meteor Show Peaks This Week

Moonlight can cut observers' hourly rates by a half, three-quarters, or more if the nearly full moon is in the sky and shining directly in their eyes. Therefore, night owls who stay up to the wee hours of the morning will have the best chances of seeing any shooting stars, Gramer said.

SOURCE | NationalGeographic.com | Read more...

Meteor Shower Viewing Guide

I just noticed this a minute ago. Look outside and see what you see! The moon might cause you trouble, but see if you can snap some pictures and post them here!




posted on Jul, 28 2007 @ 05:25 PM
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The Delta Aquarids is lightly to be a bit of a disappointment this year due to the moon's interference - most meteors from this shower are lightly to be faint, and will be lost in the moonlight. If you are not in a city or large town and can get to a dark-sky observing site, and the sky is free from cloud, then it's probably worth a try, but I'm not sure that I'd recommend it to a beginner.

A better bet would be to wait for the Perseids, which is only a couple of weeks away now, and it should be a much better show, with the moon out of the way. Rates will be better too - a meteor every minute at peak rather than one every 3 minutes for the Delta Aquarids (assuming you are observing from a rural location away from man made lights).

Getting a *good* photograph of a meteor is not as easy as it might seem, even during a shower peak. It's amazing how many appear just outside the field of view of the camera lens, and in between exposures - it can get very frustrating! When you do eventually "get one", the chances are it won't be visible, or if it is, it's just a barely visible "hair-line" streak when you view the photo at high resolution.

There are numerous other things which can go wrong and mess up an otherwise good shot, but having said that, don't let me put you off trying. It is very rewarding once you do manage to get a nice shot of a meteor!

To increase your chances, it's a good idea to do a little research on the subject of meteor photography. Here is one page with very good info.

One thing you will need is a tripod, and of course a camera which can take long exposures. The longer the exposure, the more chance you have of catching one, but be careful not to expose too long, especially if there are street lights or a town not far away, as you'll just end up recording light pollution. It's a good idea to take a few test shots before hand (try 10 sec, 20sec, 30 sec etc... even up to 5 mins if you have a *very* dark sky) if you can to find out how long you can expose for without the sky washing out. The darker your observing site is, the easier it will be to get a good shot.

There are quite a few things that can spoil a good shot as I said before, but I can't really get into too much detail here, so do a search for "meteor photography" and/or "star trails" (which is essentially very similar) and read up on it if you want to take good shots.

Good luck, and post up any good shots you get here



posted on Jul, 28 2007 @ 07:11 PM
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Would anyone happen to know what time? Well what time CST it would be and when would be the best time to view it?



posted on Jul, 28 2007 @ 07:18 PM
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Long exposures are ok, but you have to be careful not to do too long ones for 3 reasons:
1) To get a long exposure you need to dim down the aperture, which then will make the visible meteors dimmer. On a worst case scenario faint meteors dont show up at all. Or alternatively you will over expose the sky and it wont look like a night anymore, photoshop can fix this thouhg.
2) Digital cameras take long time to process long exposures if you have the noise reduction on, you must remember to turn it off.
3) Stars start to move too much very easily.

I'd recommend a shorter exposure but use continous shooting and if you have wire trigger then lock it down and let the camera go on as long as you have room on the card or battery power


[Edit] Pesky typos


[edit on 28/7/2007 by PsykoOps]



posted on Jul, 28 2007 @ 10:25 PM
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Which way are you to look in the sky?



posted on Jul, 29 2007 @ 02:25 AM
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Originally posted by mnmcandiez
Which way are you to look in the sky?


Originally posted by cav01c14
Would anyone happen to know what time?

I think this answers both your questions...


The Delta Aquarids are best viewed in the pre-dawn hours away from the glow of city lights. Southern Hemisphere viewers usually get a better show because the radiant is higher in the sky during the peak season. Since the radiant is above the southern horizon for Northern Hemisphere viewers, meteors will primarily be fanning out through all compass points from east to north to west. Few meteors will be seen heading southward, unless they are fairly short and near the radiant.

SOURCE | Wikipedia.com | Read more...



posted on Jul, 29 2007 @ 03:46 AM
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I'm in the UK. Have you any idea which direction I should look? Is there a constellation I should point myself at? I know when it's the leonids I should look in the direction of Leo. With the Delta Aquarids should I be looking for Aquarius? Sorry if I sound dim, I love the sky but can't find my way round it very well.



posted on Jul, 29 2007 @ 04:01 AM
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From what I understand, your best bet is to look southwest as close to the horizon as possible. I'm surrounded by trees and city lights, but am planning a trip to the mountains to try and catch the perseids week after next. Happy hunting



posted on Jul, 29 2007 @ 07:39 AM
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Originally posted by PsykoOps
1) To get a long exposure you need to dim down the aperture



Not necessarily, but you need to be somewhere away from artificial light (and the moon won't help either!). This is why it is best to do some test shots and see how long you can expose for before over-exposure of the sky occurs. The last thing you want to do is over expose - any meteors you do capture will be lost in the bright sky, and it is not at all easy to correct in photoshop, especially if you are shooting jpegs rather than raws, which most people here probably will be.

The exposure times that I suggested to try are actually relatively short as long exposures go (I'm assuming that most here are not living in the middle of nowhere and probably won't travel a long way to get away from light pollution). If the sky is very clear and free from light pollution then a 30 second exposure should be easy to do without over exposing, and you won't fill up you camera's buffer or memory card so quickly, which means less time lost in between shots, and therefore a better chance of catching meteors.

However, you also have to look out for "amp-glow" which will get worse with long exposure. This is due to your sensor's amplifier heating up, which will cause a "glowing" area on one side of the photo. This can only be removed if you take an identical exposure with the lens capped, and then later subtract that from your original shot in post-processing. If you are taking lots of exposures over a long period then you will have to do this every so often, as the sensor's temperature changes.

You should use the maximum aperture your camera/lens will allow, and also the highest ISO that you can use without the effect of noise becoming too prevalent (in-camera noise reduction is not a good idea for meteor photograph as you say). This combined with long exposure will give you the best chance of catching a meteor, as long as you follow the above directions.

Using a remote release if one is available for your camera is the best way, otherwise you need to use the timer for a delayed release. Not doing so will cause camera shake and messed up stars.

The question of exposing long enough for the stars to trail is a matter of personal preference. The wider your lens, the more time you can expose without the stars trailing, but this also brings up other issues (see the link I posted in my previous post).

Another issue is that your battery will run down surprisingly quickly at night (if it's cold - and it usually is!), so you want a spare at hand if possible, or to run your camera off an external power source.

Hope this clears everything up.



posted on Jul, 29 2007 @ 07:53 AM
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Originally posted by mnmcandiez
Which way are you to look in the sky?


The simple answer is - straight up! ...this is because meteors can appear anywhere in the sky (when a shower is active, and the "radiant" is above the horizon). If you look at where the meteors are coming from, you will miss meteors that are behind you.

By looking straight up, you will catch the most meteors possible, since you can use your peripheral vision to monitor the horizons all around you, and then turn your head if need be to get a better look at anything catching your eye close to the horizon.

Getting horizontal with the aid of a sleeping bag and groundsheet/reclining lawn-chair is by far the best way. You also want to pick a spot that gives you maximum sky coverage, with least obstruction from trees, buildings etc.



posted on Jul, 29 2007 @ 08:03 AM
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Originally posted by wigit
I'm in the UK. Have you any idea which direction I should look? Is there a constellation I should point myself at? I know when it's the leonids I should look in the direction of Leo. With the Delta Aquarids should I be looking for Aquarius? Sorry if I sound dim, I love the sky but can't find my way round it very well.


Not a stupid question at all... most people starting out are not sure which way to look! As I said in my previous post, you want to look up... but I should also add, it can help a bit if you have a slight bias towards the direction where the shower is coming from, in this case Aquarius. Lie down with your legs in the direction of Aquarius, ie pointing South, and look directly up, or slightly to the South of the Zenith.



posted on Jul, 29 2007 @ 08:26 AM
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Originally posted by HaveSeen4Myself
From what I understand, your best bet is to look southwest as close to the horizon as possible. I'm surrounded by trees and city lights, but am planning a trip to the mountains to try and catch the perseids week after next. Happy hunting


See my above posts


Good to hear you are going to make the effort to get out into the wilderness - it's well worth the effort to find a dark sky, especially for the Perseids. Watch that the weather doesn't catch you out though - keep an eye on the forecast, and if it is looking bad for the main night (Sunday) then consider going out the night before - like the Delta Aquarids, the peak is drawn out over a long time, but the drop in rates after the peak is more pronounced than the build up, so the nights before can be quite good as well.

It's always good to have a contingency plan with meteors, as the weather usually does not cooperate when you want it to. If you do go out, and find your observing site clouded over, give it some time before you head back home - sometimes it'll clear up unexpectedly, and you can end up having a great night.

Good luck, and may the weather gods be with you


Edit for typo and to add a little more info

[edit on 29-7-2007 by C.H.U.D.]



posted on Jul, 29 2007 @ 08:27 AM
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Chud there's always the moon factor that you have to take into account. That causes alot of ambient light and in long exposures it can kill very good images. You should of course try how bad the effect is depending on your position and what part of the sky you want to capture. Always use your lens hood to deflect as much of the ambient light as possible.
Do you have any sources for that "amp-glow" I've never even heard of that?
I'd recommend shooting continously with about like 5-10 sec. exposures as long as you can. Most wire releases have a lock so you can keep it down so the camera keeps shooting as long as it can.
Ccd noise in sky photography is really disturbing so boost your iso just as much you need.



posted on Jul, 29 2007 @ 08:35 AM
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Originally posted by cav01c14
Would anyone happen to know what time? Well what time CST it would be and when would be the best time to view it?


After midnight is the best time to look. Since the peak is a wide one, the time of observation is not all that important, as long as Aquarius is above the horizon, which it is for the duration of the night. You will still see some before midnight, but not quite as many as after.



posted on Jul, 29 2007 @ 08:59 AM
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Originally posted by PsykoOps
Chud there's always the moon factor that you have to take into account. That causes alot of ambient light and in long exposures it can kill very good images. You should of course try how bad the effect is depending on your position and what part of the sky you want to capture. Always use your lens hood to deflect as much of the ambient light as possible.
Do you have any sources for that "amp-glow" I've never even heard of that?
I'd recommend shooting continously with about like 5-10 sec. exposures as long as you can. Most wire releases have a lock so you can keep it down so the camera keeps shooting as long as it can.
Ccd noise in sky photography is really disturbing so boost your iso just as much you need.


PsykoOps, yes, I did mention the moon factor, which is why it's a good thing to do some test shots to see how long you can expose for.

Obviously, you don't want to point your lens in the vicinity of the moon as this will shorten you maximum exposure time, and make any meteors you capture stand out less against the sky. If the sky is very transparent the effect will be less, but any haze will make matters much worse. Aiming 90 degrees away from the moon is the best tactic.

Good point about using a lens hood - as well as preventing stray light from getting in your lens and lowering contrast, it will also help to keep your lens from dewing up, which can be a real problem in astro photography.

See this link for some info on amp-glow.

5-10 second exposures are a little bit short, unless you have lots of light pollution. The best thing to do is try various exposures, and see what works best for you.



posted on Jul, 29 2007 @ 09:05 AM
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Turns out that my D200 is nutorious for amp glow. But that is an issue only when you shoot really long exposures. Like +1min and so.



posted on Jul, 29 2007 @ 09:06 AM
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To be honest, I'd save the effort for the Perseids, which is usually a much more photogenic shower, as the meteors can be very bright (as well as being more numerous). Having said that, meteor showers can be very unpredictable, and you never know you luck until you try



posted on Jul, 29 2007 @ 09:17 AM
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Originally posted by PsykoOps
Turns out that my D200 is nutorious for amp glow. But that is an issue only when you shoot really long exposures. Like +1min and so.


That's not too bad... I've had issues with 30sec exposures on one of my Nikons, but allot depends on your shooting conditions, and settings.

I've since moved to Canon, because their sensors are much less susceptible to it, and there are other advantages like lower noise at high ISOs - they are leaps and bounds ahead of Nikon in these respects.

Edit for typo

[edit on 29-7-2007 by C.H.U.D.]



posted on Jul, 29 2007 @ 09:28 AM
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D80 had a serious issue with this aswell, some people experienced it with 1/60s. iso1600. Well, I dont do alot of long exposures so I guess I'm safe



posted on Jul, 29 2007 @ 10:12 AM
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That sounds like a pretty serious fault to me. 1/60 is not that long of an exposure!


Glad I'm not with Nikon any more, although their cameras are nice in most other respects, and they have a good lens lineup.

I still use Nikon lenses on my Canon bodies, and they give me better results than when I use them on my Nikons!



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