Align mount after an auto two star EQ align

Here we have Messier 3 again. Not as good as this attempt from a while back, but then again, I was kinda tired this evening so I didn’t take too many exposures. This is a stack of about 50 exposures (10 seconds each), handpicked from the whole viewing session. The sky was pretty light polluted (as is always the case in this area of the world), but there was no Moon to add to the light misery. Telescope was still the Celestron NexStar 5SE with a GPS module and a light pollution filter.

But… this was the first time I had my mount EQ aligned and “wedge aligned” as well when looking at a globular cluster. Because I had the new firmware installed, things changed some. I must say it is a lot easier, so I’ll explain the steps below for your entertainment.

I also got one of these, so I can take the telescope everywhere. It’s really nice to have a Celestron Power Tank instead of a mains AC-DC adapter like I used to have:

EQ aligning the telescope just starts out as usual. You can use my description here to get started. It still just starts with the usual EQ North Align (if you happen to live in the Northern hemisphere of course).

After a successful EQ North Align you can leave the starfinder on to continue with an Align Mount. This used to be called a Wedge Align, but this menu item is no longer available in the new firmware. Align Mount lets you align the mount on any object, so there’s no reason to align the wedge on Polaris anymore. How convenient!

From the alignment menu, choose Polar Align – Align Mount.

You will then have to perform the usual align (first a rough alignment with the starfinder, then centering the object with fine control) with the last object you used in the auto two star EQ North align.

Now comes the tricky part, because you will have to move the mount and the mechanical wedge tilt adjustment to re-center the object. As the hand control says: DO NOT USE THE DIRECTIONAL BUTTONS FOR THIS!

If you’ve never done this before, it might take some getting used to. When I was 12, I had a really simpe telescope without any motor control, so I had lots of experience with manually finding objects. I even managed to follow airplanes and catch the occasional satellite with nothing but manual control! Anyways, you’re gonna have to do the same to do an Align Mount. It’s not that hard, because the object is pretty much centered already. Just gradually move it into the red dot in your starfinder. It doesn’t really matter if you first move the telescope tripod or adjust the wedge tilt screw first:

When you’ve got the object dead center in the eyepiece of your telescope, hit ENTER and your telescope is now aligned even better than a standard EQ North Align. You may still have to use Precise GOTO, which is one of the best features of the NexStar telescope. It helped me find this comet and even the faintest objects. Be sure to check out Precise GOTO, because it’s such an eye-opener once you understand how it works and it means the difference between frustration (when the object you’re hunting for doesn’t show up) and success, when that faint object appears in the middle of your eyepiece, even in impossibly light polluted areas such as Utrecht, the Netherlands.

Comet C/2011 L4 PANSTARRS

 

Comet C/2011 L4 PANSTARRS on April 20, 2013, 23:00 hours. Zeist, the Netherlands, backyard. This is a highly light polluted area and the moon wasn’t helping either. Celestron NexStar 5SE with light pollution filter, Alt-Az aligned. Found the comet using a precise goto at RA 0h21m47s, DE +58º09’58″. Meade DSI II pro ccd camera. Stack of 45 frames, stacked and processed in Nebulosity and Adobe Photoshop Elements.

Here’s a screenshot of Stellarium, which provided the exact coordinates of the comet for my location. Such a wonderful tool! I’ll describe how to easily find comets in Stellarium some other time.

 

Long exposure of International Space Station on April 19, 2013

 

This is a 15″ exposure using a Canon SX 200 IS PowerShot on a tripod. All manual settings. I was warned about this pass by the wonderful Sputnik iOS app on my iPhone. In this photo you also see an overexposed Moon and several stars of the constellation Leo, through which the ISS was going at that time.

Firmware updates

Have you ever considered updating the firmware of your Celestron NexStar? My hand control was running version NXS 4.13 and my motor control was running version 5.13, so updating my firmware was long overdue. In case you didn’t know: the Celestron NexStar 5SE contains two separate computers that each run their own firmware version. You can find the versions of your telescope’s firmware via the Utilities - Version menu:

Why would you update your firmware to begin with? You can be sure that your telescope will run with more precision and less bugs with a newer version of the firmware. And amazingly, my NexStar is now more quiet than it was before! A very good reason to have updated the motor control firmware indeed! Read all about it here if you are curious.

The Celestron firmware update software is available only for the Windows operating system. So I decided to update my telescope’s firmware via Parallels for OSX, since I am using a Macbook Pro with OSX.

First I had to get the correct cable(s), though. To update the telescope’s firmware, you either need an old computer that still has an RS232 serial port, or a USB-to-serial adapter. With my Macbook Pro, I had to opt for the latter.

I bought a Plugable USB to RS-232 DB9 Serial Adapter (Prolific PL2303HX Rev D Chipset) on amazon.com for $12.95. You also need an rs232 cable that connects to the bottom of your hand control. Read all about it here. I got my rs232-to-handcontroller cable at our local Celestron dealer,
http://www.ganymedeshop.nl/
. Here you can see how that cable connects to the hand control:

I downloaded two installers from the Celestron site. One to update the motor control firmware (MCUpdate), the other to update the hand control firmware (HCUpdate). After installation, I started with the motor control update. MCUpdate allowed me to download the latest version via the web. You can see how this looks further below, where I describe the hand control firmware update, which uses a very similar procedure. I had to connect to COM3 in order to communicate with the telescope, but your COM settings may differ.

After clicking on “Begin programming”, the motor control firmware was updated. It took a few minutes to complete, during which time the hand control was in a locked state.

Updating the Hand Control firmware was very similar. Again, I had to choose COM3. But in order to update the hand control firmware, I had to hold down the INFO and UNDO buttons on the hand control while turning on the power. This resulted in the following message:

Like MCUpdate, HCUpdate also let me download the latest firmware version from the web:

After clicking “Begin programming”, the software again showed me the progress of the firmware update:

For me the whole procedure was completely painless. It took a few minutes to update each firmware version. Be sure to follow all the prompts, both from the Celestron update software and those on the hand control of your NexStar 5SE. For instance, at a certain point during the procedure I had to power cycle the telescope. But when all was finished, the Utilities - Version menu happily showed me that the new versions were installed:

Polar alignment and Messier 81

That’s M81, first time I found it in this light polluted town. Also the first time I polar aligned my Celestron NexStar 5SE. I highly recommend polar aligning your scope, especially when you’re gonna do astrophotography. Why? Because a polar aligned telescope only turns on one motor (i.e. more precision) and the photos don’t rotate from one frame to the other. But because the alignment procedure is quite involved and not well documented in the manual (or on the internet for that matter), here’s what to do if you too live on the Northern hemisphere. PS: This is the absolute minimum. We’ll cover an additional wedge align in another post.

1) The NexStar 5SE has a wedge. This wedge must be lifted such that it’s adjusted for your latitude. In my case, I live at latitude 52º, so I align the base plate to the 52º mark. You can do this during day time:

2) Setup your telescope outside to let it adjust to the temperature and power on the NexStar computer and the GPS. Set it up in this initial position, pointing to Polaris. You can move the tripod around such that Polaris is more or less centered. It is important that you point your telescope to Polaris as good as you can.

3) Wait until the GPS is linked:

4) When the GPS is linked, choose EQ North Align:

5) The first thing the NexStar asks you to do is “Set Alt to Index”. You need some light (e.g. from a red lantern) for this, and it means that you use the up/down controls of your NexStar hand control to align the two arrows:

When you have done this, the telescope is pointing towards the ground! This is exactly as it should be!

6) The NexStar now asks you to “Find the Meridian”. This is the tricky bit:

You now have to slew the telescope with the hand control’s right arrow button so that it points towards the sky AND is aligned to the meridian. In the sky, the meridian is the imaginary great circle on the celestial sphere. It passes through the north point on the horizon, through the celestial pole, up to the zenith, through the south point on the horizon, and through the nadir, and is perpendicular to the local horizon. This means you have to swing the telescope clockwise for a half turn until it points to the sky again, away from Polaris. It helps me to put my iPhone with a compass app on top of the telescope until it is aligned North to South:

Your telescope now points to the sky, away from Polaris!

7) Now choose “EQ Auto Align” and align the telescope as you normally would do to two of the suggested stars:

8) Voila! Your NexStar is now polar aligned. For more accuracy, you can still use “Precise GOTO“. In fact, that’s how I found the above Messier 81. My first trial with the regular Messier menu found nothing. But “Precise GOTO” yielded a much better result; M81, dead center!

Of course I would like to improve on this result. I think I can aim a little higher on the following, considering the equipment stays the same:

• Find a place with less light pollution.
• Take more pictures.
• Also do a wedge align and generally make sure M81 stays better centered on the ccd.
• Spend more time focusing.
• Experiment with exposure settings. At 10″, M81 seems to “blow out” at the center. So less may be more here.

Stay tuned for another photo of M81.

Comet C/2009 P1 Garrad

Just like comet Hartley 2, I found this very faint (magnitude 8.3) comet C/2009 P1 Garrad using PRECISE GOTO on my Celestron NexStar 5SE with the exact coordinates of C/2009 P1 Garrad at that time, according to Carinasoft Voyager 4.5 software.

You can see the UTC date and time in this picture. I took a few dozen frames using my Meade DSI II pro ccd camera attached to my Celestron NexStar 5SE telescope. I was standing in front of our house in Zeist, the Netherlands, which is terribly light polluted. Finding a comet of magnitude 8.3 is pushing the limits of what can be seen in this area, so I was glad I could find it quite easily with my NexStar auto two star aligned to Vega and Altair. It was a beautiful night and the moon wasn’t up yet.

Celestron on facebook

Hens Zimmerman likes

Celestron Telescopes

Create your Like Badge

Do real science

Moon Zoo: Crater Survey from The Zooniverse on Vimeo.

And if you think that’s all, check out
http://www.zooniverse.org
. There are many projects you can become a part of. Sure beats playin’ Solitaire!

To compare….

You decide; the above picture of M3 was taken with Teide 2 at slooh.com, under excellent weather conditions in the Canary Islands in Spain, virtually free from light pollution. I reserved a slot on Sunday, April 10, 2011 to get this image of M3 and compare it with my own. The specs of the telescope are:

Dome 2
Primary Instrument: 0.35 meter f/11 Schmidt-Cassegrain
Field of View: 13.1 × 8.8 arc-minutes
Camera Resolution: 2,184 × 1,472 pixels

Compare this to my picture with a modest NexStar 5SE in my light polluted backyard.

Limits… or not

This is my latest picture of Messier 3. I took a few hundred images of 6 seconds each using Nebulosity with my Macbook Pro in the garden. On top of my Celestron NexStar 5SE telescope was a dew cap, which does make a lot of difference it turns out. The Lumicon deep sky filter was also in place (just before the zenith prism). All images were taken with the Meade DSI II pro ccd camera. From time to time I hand adjusted the NexStar to center the globular cluster M3 in the ccd. I don’t autoguide (yet). The NexStar 5SE isn’t equipped to use an autoguider, though I’m sure it would be possible to hack together some sort of autoguiding system. In fact, I wouldn’t be surprised if the electronics are identical to the NexStar 6SE which does have an autoguider port. But enough about that.

Inside, I handpicked the best pictures, which left me with 266 frames to stack in Nebulosity. I subtracted with a bad pixel map and aligned all the pictures using Translation + Rotation + Scale while saving each file instead of a stack. I love this technique, because I can then preview all the aligned pictures and toss out the ones that are slightly mis-aligned, or blurry. I find it easier to decide when I see all the pictures aligned. I then stacked the remaining frames using None (fixed) and did some post processing with curves and levels. I sharpened the image using Sharpen. I find Sharpen and Laplacian sharpen filter nicer for globular clusters than Tighten star edges.

Of course it took me at least 6 hours in total (imaging and post processing) to create the above picture. Which brings me to the limits of image quality. I created a similar photo of M3 months ago, and that photo was of much less quality. There is of course a sharp limit in terms of image resolution, based on the diameter of the main mirror of the NexStar 5SE, which is five inches. Maybe the above picture is hitting that limit. But the light pollution and the camera quality – which could easily be blamed for lesser quality pictures by a novice – certainly aren’t the true limits of taking beautiful pictures. By taking enough pictures and taking the time to read the manual of Nebulosity (and trying out several techniques), it seems to me that the picture quality to a certain degree is a function of the amount of time spent. Or should we say, the lack of boredom