Skip to main content

Posts

Showing posts from 2014

[SOLVED] NexStar 4SE Does Not Power Up

About a month or so back I realised that there is another problem with the 4SE, it wouldn't power up. Firstly I thought this was due to a battery drain, and that's the first thing I tried. While it worked once, after about half an hour of sky watching it stopped working again. It is quite improbable for a new set of batteries to drain that fast. After hooking up with a 12V 2A power supply, it still did not power up. This could mean two things: the power doesn't get to the circuitry or the circuitry it self is busted. After playing around a bit with a multimeter, the fault turns out to be... again on the switch . I think it is fair to assume that the part that has most physical/mechanical movement will be the first to fail. It is true that the electronics could fail, but I guess it is better to start from the switches. For the moment, I have bypassed the switch, and all is well (well except for the weather...)

More Sunspots

Sunspot group AR2209

Giant Sunspot Group - AR 2192

A giant sunspot group, AR2192, has formed on the sun again, and the group is now larger than the largest sunspot group we saw last year, making this the biggest sunspot group in the decade. AR2192 - 500mm Samyang Mirror Lens, Baader Solar Filter If you would like to know how big this really is, have a look at this image done by Paul Floyd at nightskyonline.info Copyright - Paul Floyd / nightskyonline.info The images below show my own images comparing the previous holder of the largest sunspot group of the decade that erupted last year: The group has caused several flares already, but there hasn't been any coronal mass ejections. A coronal mass ejection would pretty much guarantee that there would be massive auroral activity.

Lightening Photography

I have not been able to do any decent astrophotogaphy sessions recently. The rains are here and here comes the lightening shots. I'm fascinated of how it always strikes over the sea. All photos were taken with a 30s exposure F8.0 and F5.6 on a tripod. That actually makes it easier to capture lightening. You don't really have to do anything. The downside is that if there is some sort of ambient lighting, then your photo is likely to get washed out. You can step around this problem by having smaller exposure times.

[SOLVED] Nexstar 4SE Alignment and Sync issues

Few days back, when I was trying to do some random stellar observations, I realised that the 4SE wasn't aligning properly and the goto function was off a little more than you'd expect. Given that weather wasn't on my side, I decided to let it go for the moment. I finally made a one star alignment and was trying to get the Sync function to work (the Sync function, when activated, would track the current position it is pointed to by auto adjusting to compensate for the stellar movement). The first worrying point when the controller returned an error that said "Offset too large, Sync failed". Yesterday, while I was trying the same, I was trying to align the telescope using the Two Star Alignment mode. After trying to align using two reasonably nearby stars (Alpha Centuri and Hadar and repeating with Alpha Centuri and Acrux), the controller was returning an error that said "Align failed". This was even more worrying. It is only slightly later that I rea...

Crowdsourced Astrophotography

Since it is the monsoon season again, I've been thinking of writing something about astrophotography rather than actually engaging in it. Coincidentally, one of my friends sent in an article based on some scholarly work where the team was working on combining deep space photos that are general public to create more detailed photos which are comparable with the ones that are taken from the most cutting edge telescopes. This is infact, what we all do as amateur astrophotographers. However the challenge for combining images from a large number of sources lies in the fact that you don't know what conditions they were shot under and whether all of them are of comparable quality.In this research, the team managed to set up a system where it queries for popular image search services for a given object, runs the images through a 'space locationing' software to get the accurate corrdinates, stacks them and enhances the image. The researchers claim that due to the sheer number o...

[SOLVED] NexStar 4SE finderscope / starfinder / spotterscope not working

During a failed attempt to observe and photograph the Camelopardalids meteor shower, I found out that the finderscope of the 4SE was not working. If you have not done this, try doing it, it is ridiculously hard to successfully aim the telescope at anything if your finderscope is not working. After testing with multiple batteries, my immediate worry was that the LED in the finderscope may have burnt out. If this was the case it would be quite hard to fix it. That's when I decided to dismantle the finderscope to pinpoint what exactly went wrong. Removing the finderscope from the telescope is quite easy. You need to unscrew the two bolts on the side of the finderscope, just under the switch and the calibration screws. Once done, you need to remove the unscrew the calibration screws themselves. You need to hold the calibration screw with one hand and unscrew the bolt. The calibration screw will otherwise turn along with the bolt. And this is what the inside look...

Spot The Planets - 2

I was going to wait till I get a good shot of Mercury before I posted this. But it is unlikely that I would be able to do stargazing in the next few weeks, so decided to put up what I managed to capture yesterday and today. Venus - 25th Jan 2014 Mars - 26th Jan 2014 Jupiter - 26th Jan 2014 Saturn - 26th Jan 2014 All the images were taken using Canon 550D's Movie Crop mode, exporting the file as a avi in Canon ZoomBrowser and then stacking them all on Registax. I guess I still have a lot to learn about wavelet processing! All the images above are comparable in their apparent sizes except for Venus. Venus looks like 50% of the width and height pictured above (yes even then, Venus looks larger than Jupiter because it is very close to Earth these days). I am quite ecstatic about the whole shoot because I managed to capture all the planets barring Mercury and to a reasonable detail. I didn't expect the GRS on Jupiter or the Cassini Divide on Saturn or the featu...

Spot the planets

This is a good month to spot the planets, the whole five of them which are visible to the naked eye. As soon as the sun sets, check the western skies and you will see a very bright star very close to the horizon. This is in fact not a star but the planet closest to the sun, Mercury. Mercury - Evening of 26th Jan 2014 Next to appear on the skies is Jupiter, the largest of the planets and a gas giant. Check around 7PM towards the eastern sky. Locate Orion and draw a diagonal using the two corner stars of Orion towards North East. Jupiter would be close to that line and will be very bright. In fact, if it is cloudy, Jupiter's might be the only light you can see. Jupiter - Evening 26th Jan 2014 Mars appears on the sky at around  mid night. But if you wait till around 5:15-5:20 in the morning, it will be directly above your head with a slight reddish tint. The brightest stars you will see around this would be Spica (closest to Mars) and Arcturus. Mars - Morning 27th Jan...

One of the largest sunspot group in a decade: AR1944

The year 2014 started off with a discovery of a giant sunspot group later named AR1944. NASA stated that the group was one of the largest seen in the last nine years. Out of pure coincidence, I managed to capture an image of the group on 5th Jan and I repeated the exercise today after learning that I caught an image of a fairly important activity. The two images are shown above side-by-side for comparison. (The "cutoff" of the solar disc is not due to a bad crop. The Sun is too large to be photographed via a NexStar4SE and a 550D without a focal reducer, it is just just a little bit larger than the CCD). At the time, predictions were on that there could be a massive solar flare, heightened aurora activity and a disruption to electronics including satellite communication and navigation systems. On 7th January, an X class solar flare erupted and reached Earth around 9th and 10th. Although there are no reports of communication disruptions, everybody is expecting the...

Jupiter Closest to Earth Today. Photo Opportunity!

If you are a owner of a camera which has more than 10x zoom (better yet if you have a DSLR and a zoom lens longer than 100mm), you have a good chance of catching Jupiter with its moon on photo today. Jupiter is closest to Earth today. This means it passes roughly around 628 million km from Earth compared to the 928 million km when it's farthest from the Earth. Naturally the closer approach allows you to resolve the details of the planet much better. If you are a Sri Lankan, Jupiter rises from the east pretty much as soon as the sun sets and passes you over head around 20 minutes past mid night. Look towards the east (almost direct east, not north east, or south east) and try to find the brightest object you can see. That is Jupiter. Since a lot of people can recognise the constellation Orion, that also is a good starting point. Draw a line from the top star of the Orion's Belt through his shoulder and that line passes close to Jupiter. Jupiter it self is very bright, s...