Finding dim objects

Sometimes a dim object like M1 (Crab Nebula) can be difficult to locate as it may take a long time looking through the eyepiece before it becomes visible. This is the method I used to find M1.

If I am scanning the sky and come across an object I want to identify, I use an iPad running Star Chart or this Pushto method if I am using an Android phone.

A tablet is easier to use than a phone. The Star Map iPad application is free of advertising and clutter. Even though it is no longer developed it works really well. It is now my default way of locating Messier/NGC objects.  I would use SkEye if I had an Android tablet.

Using Stellarium

Run the desktop version of Stellarium and ensure that my finder and lowest power, wide-angle (WA) eyepiece have been added to the ocular section.

Locate the nearest visible star (Tianguan) in Stellarium and switch to ocular view. I first select the finder view to determine the direction I need to move. I then select the WA EP and take a screenshot (Ctrl + Print Scrn on Windows).

Open the paint app (I use Affinity Paint) and paste the clipboard.

From the layer toolbar, I select invert. This is done to reduce the amount of black ink when printing.

Using the arrow keys of my keyboard, I move towards M1 taking a screenshot and repeating step 2 to 4 above. With my low power EP, it takes three jumps to get to M1. I try and keep a point of reference like Tianguan or an asterism in the screenshot so that I do not get lost.

I then have three printouts at the eyepiece. I make sure these are in order and can add arrows to show the direction I need to move the telescope.

I use asterisms and obvious stars (a, b and c) to identify where to look for M1 as it is definitely not as obvious as in the image.

Writing the instructions takes far longer than actually going through the procedure but I would only ever target a dim object like M1 or a galaxy when conditions are good and there is no moon for example.

It is quicker to have a star map like Star Chart on a tablet which will allow you to zoom and out and locate objects by finding star asterisms.


 

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