Wednesday, November 21, 2018

Fun with the New Imager

Beep. Beep.  Beep.

That's the sound that my wrist alarm made at 1am this morning.  I set an alarm on my running watch to awaken me so I could do an early morning astronomy session.

I like to use the running watch for astronomy purposes because it's GPS accurate and strapped to my wrist.  No risk of dropping my beloved Pixel phone on the concrete driveway while fiddling with the time and date settings of the telescope's hand controller.

The moon was 98 percent illuminated -- it flooded the entire night sky, drowning out all but the brightest stars.

No matter.  I was merely interested in getting some under-the-sky time with the newly arrived ZWO ASI294MC imager.  The full moon is useful for testing new equipment.  It lets you see what you are doing while whirling unfamiliar knobs and twiddling unaccustomed levers in what would otherwise be pitch blackness.

I pointed the telescope at some of my favorite objects, getting a feel for the benefits of its comparatively larger field of view.

The brightness of the moon emphasized to me that "serious" astronomy was not to be done during this session.


Take for instance, this image of M51, the Whirlpool Galaxy.  It's washed out by the moonlight.  This object was one of the first that I visited this morning.  It's pretty much the best I could do with the brightness of the moon.  I was happy to see that the image is largely free of bloated stars, but with a taste of what the new imager could do, I wanted more than just washed out space objects . . .
M51, washed out by moonlight

(Note that clicking on images in this post will open slightly larger, greater resolution versions of the images.)

I spent a few hours playing with the equipment and biding my time.  I knew that the moon was going to set at 5am.  I plotted and planned what I was going to do with that hour of darkness that I'd have between moonset and impending sunrise.

Finally.  Moonset.

I revisited M51 and captured this image.

M51, sans moonlight
I was really happy with this image of M51.  It's scaled down for purposes of the blog, but my capture of it is a full 4144x2822 pixels at 24 bits of color.


Up next? M42, the Orion Nebula.

M42, the Orion Nebula
M42 is both easy and hard.  It's easy because it is so large that you can see it and make out nebulosity with your naked eye.  It's hard because it is so bright that it is difficult to image without overexposing its central core.

But the Orion Molecular Cloud Complex, of which the Orion Nebula is part, has some difficult to see, and difficult to image objects, as well.

The Horsehead Nebula

One of these is the Horsehead Nebula.  I've never been able to see it without EAA, but this morning, after moonset, the sky transparency was above average.  I captured this image.

the Horsehead Nebula

The Flame Nebula

 Located nearby, here is the Flame Nebula.

the Flame Nebula
The bright star captured in this image of the Flame Nebula is Alnitak, the easternmost star in the Belt of Orion.

The Horsehead Nebula and the Flame Nebula

The Horsehead Nebula and the Flame Nebula are near enough to each other that I was able to rotate the imager's rectangular sensor so that both objects fit into the field of view.

Horsehead Nebula (left), Flame Nebula (right), and Alnitak (bottom edge)
There was just enough time before the encroaching sunrise to take a peek at a couple of my other favorites.

M81 and M82

Here are M81 and M82 in the same field of view.  They are a pair of gravitationally bound galaxies so it seems appropriate to present them in this manner.  😊

M82 (left) and M81 (right)
While you can barely make out the spiral structure of M81 in this resolution reduced blog image, it is pretty apparent in full scale.


M45, the Pleiades, also known as the Seven Sisters, is beautiful to see through the eyepiece.  It is a little large to fit fully in the imager's field of view, so I'm thinking that next time, I'll experiment with using a focal reducer.

The Seven Sisters
The nebulosity that is slightly apparent in this image is quite pronounced in the full scale.

The Owl Nebula

And finally, here is the Owl Nebula.  Captured while the sky was still dark, but daylight threatened.

The Owl Nebula
See the little owl "eyes" peering at you?

This set of EAA images is not too shabby for basically an hour's worth of dark sky!


  1. The difference between the two Whirlpool images is quite pronounced.

    Yes, I see the owl's eyes, cute.:-)

    1. I was amazed at how quickly the sky went from being washed out from the moonlight to being black with the Milky Way visible overhead.


Featured Post

More HyperStar Fun

Yes, more HyperStar fun! Thursday night, we finally had clear dark night. It was worthy of putting the HyperStar on the Cat. It was worthy o...

Popular Posts