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Exactly. Visibility and magnitude are very different. There are some dwarf galaxies that are magnitude 8, but because they cover nearly a degree of sky they get vastly outshone by 10th magnitude field stars.
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Mar 23, 2013 05:47
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What's the purpose of an autoguider exactly? Is it something you need for astrophotography? For example: http://www.telescopes.com/telescope-accessories/photographic/celestronnexguideautoguider.cfm
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Apr 4, 2013 02:01
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The purpose of an autoguider is to monitor your mounts tracking, and correct it for any errors whilst taking photographs. Errors come from both poor alignment, leading to declination drift and field rotation, to periodic error caused by imperfections in the mounts drive chain which can result in the tracking rate increasing and decreasing. The net result of this in your image is smeared data, most clearly seen as miss-shaped stars. The autoguider looks through either a secondary (guide) telescope, normally piggy backed on the main, or through a device called an off-axis guider. This uses a prism in the main light path to direct some light down to the guide camera. The advantage of piggy backing is that you get a nice wide field of view as you can use a smaller scope than the primary, and you can move the guide scope relative to the primary to locate guide stars. The disadvantage is that it can lead to 'differential flexure' where elements within the setup cause the guide scope to move separately from the imaging scope. Off-axis guiding avoids that issue, but is limited to a narrower field of view making it harder to locate stars. The next element is the software, the guide setup you have linked uses an onboard software system to select and monitor a star, which can be seen on the readout on the back of the camera. It then sends corrections directly to the mount via an ST4 guide port. Most guide cameras are simple USB cameras and require software running on a computer (normally 'PHD guiding') which monitors the stars movement and sends the corrections back to the mount, either via the camera if it has an onboard ST4 port, or via some other means (e.g HiTech Astro USB Guider). It's called an autoguider because once upon a time it used to be the tedious job of the lowliest student to spend all night staring down a cross hair eyepiece in a guiding scope to manually correct it for whatever photographic plate was slowly registering photons. I've recently moved from a piggyback setup to an off-axis, and just today my new QHY5L-II Mono camera turned up, which I'm very happy about, the 75% QE rate should make it much easier to locate a good guide star.
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Apr 4, 2013 14:31
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I've got a little bit of an interest on looking up at the night sky, and my son is starting to gain one as well. We go camping a lot so I figured it'd be a neat thing to have with us for when the sun goes down. I found this on craigslist and I figured I'd lowball the guy a bit and see if I get anywhere. http://pensacola.craigslist.org/for/3727612597.html Google says it's a "Tasco 45-114375 Galaxsee 4.5"" and has some mixed reviews. From what I found it retailed for $200ish new. I figure if I can pick it up on the cheap the worst that'll happen is I'm out a few bucks and/or can hock it to the next guy for what I paid for it or not much less. My questions: 1) Is it a waste of time to look at this scope? 2) What questions should I ask its owner? Any answers that are huge red flags? Thanks!
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Apr 11, 2013 22:15
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DAT RAM posted:I've got a little bit of an interest on looking up at the night sky, and my son is starting to gain one as well. We go camping a lot so I figured it'd be a neat thing to have with us for when the sun goes down. You're the sucker the current owner is hoping to hock it off to.
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Apr 11, 2013 22:38
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INTJ Mastermind posted:You're the sucker the current owner is hoping to hock it off to. Potential sucker  I'll pass on it then.
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Apr 11, 2013 22:47
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I emailed the guy just to get the exact model. He said it was a 911TR, which every review said it is hot garbage. I passed on it.
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Apr 11, 2013 23:48
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There are many fine small secondhand telescopes out there. That was not one of them. Tip; if they are advertising how much magnification it can achieve, generally it is poo poo.
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Apr 12, 2013 00:02
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Thanks for the feedback, I appreciate it a lot. I'll keep my eyes open for something better.
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Apr 12, 2013 01:02
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Yes. Magnification is your red flag. You'll do great with what your doing. Get the model. Read reviews. Ask again of you find something.
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Apr 12, 2013 01:27
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Hey folks. My wife and I will soon be moving to Malawi and have decided to take advantage of the intermittent losses of power to take up amateur star-gazing. We were recently given the following as wedding presents to get us started: The Cambridge Photographic Star Atlas Celestron SkyMaster Giant 15x70 Binoculars with Tripod Adapter and Orion SkyQuest XT8 Classic Dobsonian Telescope Based on recommendations I've read in this thread, this seems like good starting kit. I'm wondering if there are any additional charts/guides you all would recommend and also whether or not there are things we need to take into consideration as we will be gazing from the southern hemisphere (do the charts work the same way for example?) Any advice you guys have would be greatly appreciated!
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Apr 17, 2013 02:19
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Bruxism posted:Hey folks. My wife and I will soon be moving to Malawi and have decided to take advantage of the intermittent losses of power to take up amateur star-gazing. We were recently given the following as wedding presents to get us started: First off, congratulations. Okay, that is an amazing "starter kit." An easy to use dob and binoculars, can't get much better than that. Being in the Northern Hemisphere I don't know if I can help at all (especially with physical charts) but I believe that apps such as Star Walk and SkySafari have real-time tracking of stars and planets for Southern Hemisphere astronomers. I put in Malawi as a location in Star Walk and it gave me different views than where I am now (Canada). If you're on Android I believe there are astronomy apps available but unfortunately I don't know of any since I'm on iOS. This also might help a bit, and it's free: http://www.stellarium.org/ Lots of people like it and it works on OS X, Windows and Linux. I personally don't use it anymore because I use iPad apps for my observing but I have used it in the past and it's pretty great. And free! There are also really good astronomy forums (other than this one, of course) that might help you out with location specific information. Astronomy Forum is one of my favourites and the posters there are very friendly and helpful. They also have sub-forums for people in parts of the world that aren't Northern. 
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Apr 17, 2013 02:56
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As far as books and accessories, I would recommend the following: Pocket Sky Atlas by Sky Publishing. Great all-around field guide. I find it more convenient in the field than software like Sky Safari, and it's surprisingly comprehensive. Get a Rigel Qwikfinder reflex sight. It's a good lightweight HUD-style finder that's WAY better than the red dot finders that currently come with an XT8. Order a few of these: http://scopestuff.com/ss_mwt1.htm or make your own with some big ceramic ring magnets and some thin adhesive-backed felt. The tension springs on the XT8 will prevent the scope from slipping if it's out of balance, but if the balance is off you'll still get backlash when moving the scope in small increments when tracking objects across the sky. A couple magnetic weights will make life easier if you add an improved finder or use heavier eyepieces or a solar filter. If you're willing to spend a couple hundred bucks, pick up a couple of 82* eyepieces from Explore Scientific. The southern sky has some really cool poo poo like the magellanic clouds and the tarantula nebula, and you'll want to have a good wide-field eyepiece or two to soak up the sights. This is a less pressing thing than the counterweights and the finder, but they'll be good to have in the long run.
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Apr 17, 2013 19:44
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Just a heads-up that SkySafari 3 on iOS (iPhone and iPad) is currently free (down from $2.99) through April 22. Their other two higher priced apps are also discounted in case anyone is looking for the additional features.
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Apr 20, 2013 04:20
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Today's APOD is a recent Hubble shot of the Horsehead Nebula in infrared and is literally one of the most gorgeous things I've ever seen. Link
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Apr 22, 2013 23:10
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drat, why is space so amazing. I wish everyday I could just travel the speed of light and leisurely visit all the amazing places in the universe 
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Apr 23, 2013 18:53
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If anybody else is into solar observing, check out active region 1726 before it dissipates. With a white light filter or Herschel wedge it looks like a ginormous clusterfuck of sunspots. With an H-alpha rig it looks like a swirling vortex of doom. I've been observing it with my Coronado PST and it has been shooting off M-class flares like there's no tomorrow.
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Apr 23, 2013 19:03
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I was observing the sun on Saturday with a Lunt 35mm HA solar scope on loan from my society. It was really nice to be sat in the garden with a cold beer, with the kids playing and my wife painting while I did astronomy. Certainly nicer than freezing my arse off at 3am in January, I could get used to solar observing. Unfortunately none of my image came out very well, the scope seems to suffer from Newton's Rings, I need to look into how to improve that at some point.  Newton rings by tmarkuk, on Flickr
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Apr 24, 2013 15:13
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Possibly not the scope but the imager used. What are you using to take the pics? CMOS imagers are extremely susceptible to Newton rings and aren't well suited to H-alpha imaging.
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Apr 24, 2013 17:11
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Might be why then, it's a QHY8L-II. I'll try it with a friends Imaging Source CCD when time allows.
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Apr 24, 2013 18:52
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Good idea. Unfortunately if you use a CMOS sensor with an H-Alpha scope, you're gonna get Newton rings. The quality of the scope used is immaterial. From the lowliest PST to a pressure tuned LS152, they're all going to show Newton rings when used with a CMOS camera. I certainly know what you mean about getting used to solar astronomy. I bought a PST last summer and haven't looked back. It quickly became my most used telescope. Not only does it allow you to do astronomy any drat comfortable time, but the sun in H-alpha is just so drat dramatic!
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Apr 24, 2013 21:23
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So this was Sky & Telescope's most recent Facebook post... 
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May 3, 2013 20:22
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That 70s Shirt posted:So this was Sky & Telescope's most recent Facebook post... How unfortunate.
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May 3, 2013 21:17
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Look at that woman's face. She knows exactly what's going on. Brilliant troll picture.
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May 4, 2013 00:51
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This is funny. I've been putting together a good astronomy playlist for when I'm stargazing alone. So far my playlist includes: "No Words" - Alan Silvestri, Contact Soundtrack "Small Moves" - Alan Silvestri, Contact Soundtrack "Heaven and Hell, third movement" - Vangelis "Pulstar" - Vangelis "Alpha" - Vangelis "Journey of the Sorcerer" - The Eagles Deep Space Nine main theme (seasons 1-3) Star Trek First Contact main title theme "Dark Was the Night, Cold was the ground" - Blind Willie Johnson "1ere Arabesque" - Isao Tomita "Downside Up" - Peter Gabriel, New Blood "The Nest that sailed the sky" - Peter Gabriel, New Blood "The Chieftains in Orbit" - The Chieftains, Voice of Ages "Sarabande in Pencil form" - Calexico, Carried to Dust "Watching the Northern Lights" - Barenaked Ladies, All in good time "Satellite" - Dave Matthews Band "Moon" - Rusted Root "Back to the Earth" - Rusted Root I've been soliciting for suggestions on what to add next on various astronomy forums and social networking sites. On one amateur astronomy facebook group I got a scathing response that NOBODY should listen to music while observing, that it's irritating to other astronomers (in spite of the fact that I specifically said I enjoy music when stargazing ALONE) and that I should quit amateur astronomy entirely because my "behavior is degrading to the hobby." I never knew there were such pretentious hipster pieces of poo poo in the hobby! Anyway, anybody got any good suggestions on what to add? I'm focusing on mellow and atmospheric music that isn't too heavily electronic.
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May 7, 2013 03:14
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AstroZamboni posted:I've been soliciting for suggestions on what to add next on various astronomy forums and social networking sites. On one amateur astronomy facebook group I got a scathing response that NOBODY should listen to music while observing, that it's irritating to other astronomers (in spite of the fact that I specifically said I enjoy music when stargazing ALONE) and that I should quit amateur astronomy entirely because my "behavior is degrading to the hobby." I never knew there were such pretentious hipster pieces of poo poo in the hobby! Proof positive that every hobby has its  I don't know how you'd feel about Muse. But some of their stuff is pretty good. If you want something more mellow, OneRepublic Waking Up is a pretty good album.
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May 7, 2013 12:43
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"The Planets" by composer Gustav Holst
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May 8, 2013 03:02
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Also The Planets by Neue which is pretty fantastic.
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May 8, 2013 03:28
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AstroZamboni posted:I've been soliciting for suggestions on what to add next on various astronomy forums and social networking sites. On one amateur astronomy facebook group I got a scathing response that NOBODY should listen to music while observing, that it's irritating to other astronomers (in spite of the fact that I specifically said I enjoy music when stargazing ALONE) and that I should quit amateur astronomy entirely because my "behavior is degrading to the hobby." I never knew there were such pretentious hipster pieces of poo poo in the hobby! Nobody has mentioned Pink Floyd? Maybe because it's too obvious? As for those assholes on FB, gently caress 'em. Astronomy should be FUN, and if not fun at least relaxing. I honestly haven't listened to music while observing and I think I'll change that this summer. I use apps on my iPad to help while out there, should throw some music on it. Maybe some old radio shows? Be cool if there were old science fiction/anthology programs, make for good background material.
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May 9, 2013 07:51
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The obvious answer to that is Orwell's War of the World radio broadcast.
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May 9, 2013 08:17
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I've been playing around with using my Canon point-and-shoot afocally mounted on my PST and taking VGA resolution .avi movies and stacking the frames in Registax. Decent results so far.
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May 11, 2013 00:43
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PingtheMerciless posted:If I had the $$$ to buy every child I know a first telescope, it would go to this : I picked one of these up off of Amazon for $31 shipped a few weeks ago, and for that price it's enough to get a rookie addicted. I haven't gone too crazy with it yet. I have a month old infant in the house so I've been having to help take care of her and/or it's been real cloudy. One thing I didn't pick up was the accessory kit that sells separate. I was torn on it only cause it got mixed reviews (some say buy it, others say skip it). I saw a few folks in here got this scope. The 20MM eyepiece that comes with it is is waaaaaaay better than the 4MM one but I wouldn't mind a few more options. Researching eyepieces can make your head spin if you're new at this like I am.
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May 13, 2013 17:28
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Going to the music recommendations. It might sound obvious or completely stupid, but what about Modest Mouse - 3rd planet and The Stars are Projectors. E: Most of The Moon and Antarctica album actually. Kolta fucked around with this message at 15:30 on May 16, 2013 |
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May 16, 2013 10:13
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But I do a little astrophotography from time to time. Heres the sun. Tweaked a bit from its original Hydrogen Alpha image.  The sun, through a Hydrogen alpha filtered solar telescope onto my 550D, enhanced and colour corrected in Lightroom 4. And last weekends full moon  Taken through a 1200mm Dobsonian. These were taken using gear from AstroPetes Telescope Cafe in Brisbane, Australia. Next weekend theyre going an hour out of town to Moogerah Dam and setting up there, so I'll probably find my way down there and shoot some pictures. ** Can everyone see the moon photo, i think the permissions were setup correctly in G+ Negative Entropy fucked around with this message at 00:54 on May 27, 2013 |
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May 27, 2013 00:50
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Very nice shots (and yes, the moon photo is showing up fine). What kind of H-alpha scope were you using?
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May 27, 2013 01:37
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AstroZamboni posted:Very nice shots (and yes, the moon photo is showing up fine). What kind of H-alpha scope were you using? I'll have to ask next time I'm down there. I forget. I was quoted $4000, and balked.
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May 27, 2013 02:24
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Kommando posted:I'll have to ask next time I'm down there. I forget. I was quoted $4000, and balked.  I'll stick to simple moon and star shots.  _5250422.jpg by MrDespair, on Flickr e. just realized I haven't posted in this thread since last year. Lo-fi moon shot using a stack of old lovely teleconverters, ~ 3200mm of 35mm equivalent lens.  _5140070-Edit.jpg by MrDespair, on Flickr Don't remember what this was.  DSC_0242.jpg by MrDespair, on Flickr Why didn't I write this stuff down.  DSC_0235.jpg by MrDespair, on Flickr This was andromeda, I believe.  Andromeda2.jpg by MrDespair, on Flickr And finally a shot from the telescope I mentioned the last time I posted in this thread. Great magnification, nearly impossible to focus or track smoothly though, and big enough in the box that I had to borrow a car to actually get it anywhere. Never had much luck with it.  DSC_0045.jpg by MrDespair, on Flickr e. it was a 10" CSG, a meade LX200. Dr. Despair fucked around with this message at 19:44 on May 27, 2013 |
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May 27, 2013 19:35
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A collection of my shots from Comet PanStarrs back in mid to late March. All were taken with a Nikon D5100. All of the pictures were unguided. At first I was just taking long exposure photographs, but by the end of the apparition I had learned how to do histogram stretching and stacking, so they look a little better. March 14:  March 15:  March 19:  March 26:  March 27 (moonlight was really bad in this one):  The weather wasn't the greatest in March, and those were the only nights I was able to get out and image it. The weather was pretty bad again in early April after the moon had waned, and combined with the pretty quick fading I wasn't able to spot it again. I wish I'd had the chance to try and image it while it was passing Andromeda, but stupid springtime weather had to roll in. Hopefully I'll have a good chance to image ISON in November/December. Venusian Weasel fucked around with this message at 04:16 on May 28, 2013 |
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May 28, 2013 04:14
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Venusian Weasel posted:A collection of my shots from Comet PanStarrs back in mid to late March. All were taken with a Nikon D5100. All of the pictures were unguided. At first I was just taking long exposure photographs, but by the end of the apparition I had learned how to do histogram stretching and stacking, so they look a little better. These are boss as hell. 
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May 28, 2013 04:33
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Anybody else in this thread working on Astronomical League observing programs? I just finished the basic level outreach award and I'm deep into working on the Sunspotter, Messier and Binocular Messier awards. They're a lot of fun.
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Jun 2, 2013 16:12
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