Astrophotography with a Dobsonian

I have been surrounded by quite a few interesting things over the last few months. Here is what I have been doing..."Researching" ... Researching on Astrophotography!

Fact: It is not possible to take GREAT pictures with a Dobsonian... Agreed!
Truth: It is possible to take reasonably good pictures with a Dobsonian.

Let me explain...

Astro enthusiasts know this already, that celestial objects are not stationary in the sky... they keep moving... well, not exactly... Earth spins and so it appears as if the celestial objects are moving. In any case it appears as if they are moving. Now, with a dobsonian, one will have to manually adjust and align the object under observation repeatedly... which could be quiet some pain(especially at 300 and above magnifications the objects under observation travel pretty fast).

Concept for equitorial mount: In order to have the object under observation at the center of the viewer... we will have to compensate for the motion of the Earth (Earth rotates from west to east... hence all objects appear to rise from the east and set in the west). Compensation would mean... if we place our telescope on a devise that rotates it in the opposite direction to that of the earth... the earths motion and the telescopes motion will cancel each other and the object of observation will remain "still" at the center of the viewer.

Method: After a lot of research, I found that the equitorial mount will be the best solution. Building this would take a little bit of engineering drawing, little electronics and carpentary. If it sounds hard... well... it is!

By the way... you must be thinking what has Astrophotography got to do with all of this.

Concept for Astrophotography: Taking pictures during night(or on low light) is tough. as the exposure that the camera gets to the light is very less. Low light photography is done using long exposure. There are ways to do this using a ccd webcam(in my case a Logitech QuickcamPro 3000... these CCD webcams are not in production anymore so I bought one on Ebay for $45). You will need to do some modification to the circuit and a little soldering to the webcam circuit board. For a long exposure shot.. the object under observation needs to be focused at the center of the viewer for a long time( 5 sec, 10 sec, 1 min... etc depending on the object). Hence the Equitorial Mount, as it will not be humanly possible to keep the object at the center of the eyepeace manually.

Now-a-days I am trying to build this total setup from various sources available on the internet. It will at-least take me a month or so to complete this whole thing.  I plan to do a tutotial with pictures, for those of you who might be interested. Will update my progress on regular basis. Stay tuned and feel free to leave comments.

Clear skies!

Tips for looking through a telescope

Last weekend was the first time I was looking through my telescope. I had to drive 2 Hrs to get to a star party. It was fun looking at the amazing stuff people had. I looked at Jupiter(my first object through my Zhumell 10 inch) and the Orion nebule.

I knew all my theoretical stuff.. how to read a sky map? What is altitude and Azmuth? How to focus on an object and things like that... but I bet there are tons of other things that you will learn when you are actually operating the scope. Here are a few tips for people who are looking through their telescopes for the first time:

1. To start with... Always, colliminate your scope before you start. That is because when you are setting up your scope(or during logistics), chances are that the collimination is lost.

2. Find your object using the "finder scope". Next...start with the lowest magnification(say 35mm). Bring the object of observation to the center of the screen and adjuct the focus using your eyepiece. You could now, increase the magnification to the next level(say 12.5mm)... your view through the scope might not be in the center now and might be blurry. You now need to get it to the center of the screen again and focus it. You are now ready to increase it to the next magnification(say 6mm or 4mm). You need to now again bring it back to the center of the screen and re-focus it.

Note: One important thing here is to bring the image to the near perfect center of your view. Because when you go from magnification 12.5mm to 6mm or 4 mm... you are going from 96X magnification to 300X magnification. So, if the image is not in the near perfect center, you might loose the image in the 300X view.

My gateway to the Heavens!!

Check this out guys... my first telescope. A birthday gift from one of my cousins. Its a Dobsonian 10 inch Zhumell. There is a star party on the 4th of November. Cant wait to get a view through this beauty!!

Good news - Its a 10 inch, so it has got a lot of light gathering capacity... hope to get some nice views of our moon, Jupiter, some nebula and a few galaxies.

Bad news - Its a Dobsonian... does not have an equatorial mount. Since the relative position of stars, planets and our Earth keeps changing, tracking though this telescope would be tough. Taking pictures is almost impossible.

Bottom line - Great telescope for starter amateur astronomers.

Clear Skies!

Opportunity's latest picture of Mars

This image from the navigation camera on NASA's Mars Exploration Rover "Opportunity" shows surroundings of the rover's location following an 81-meter (266-foot) drive during the 2,363rd Martian day, or sol, of Opportunity's mission on Mars (that was as of Sept. 16, 2010). The terrain includes light-toned bedrock and darker ripples of wind-blown sand. Today it is the 2380th Martian day. By the way a Sol means Solar day.
FYI - 1 year on Mars in around 668 Sols.

Source: nasa.gov

Life on Alien Planet near Earth???

This is in continuation to my previous blog... Help yourself reading my previous blog too.

One of the planet's discoverers said in a briefing yesterday that "the chances of life on this planet(Gliese 581g) are 100 percent." How do we prove this? Scientists say there are several ways, but the best approach is as simple as "Listening for signals". This planet is 20.5 light years away from Earth, so human built probes won't be getting out there anytime soon :) By the way a light year is the distance traveled by light in 1 year.

Chances of life on an Earth size planet

An Earth-size planet(Gliese 581g) has been spotted orbiting a nearby star at a distance that would makes it not too hot and not too cold- just good enough for life to exist. Though there are 400 other planets that might have a life sustaining capability, scientists say, Gliese stands a very high chance.

Below is an artists illustration of how the planet might appear.

NASA's footage of first man on moon...LOST!

Really??? May be you knew, but I did not..

I cant believe this! NASA's footage of the historic Apollo 11 1969 mookwalk was lost somewhere in NASA's archives or it got erased(???) during reuse, and was found only recently...in bad shape!