Open Cluster NGC 6709

Not too far my previous post’s open cluster lies a smaller and younger NGC 6709.  Both were imaged on the same evening, but I only got 15 minute of integration due to advancing clouds.  However with these open clusters, I don’t think a greater number of frames would amount to much more details.

Open Cluster NGC 6709

Open Cluster NGC 6709

Skywatcher 80ED
Canon Rebel XTi
30 x 30sec (ISO 400)

Image is cropped and scaled 50%.

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Open Cluster NGC 6633

Open star clusters are the galaxy’s youngest stars. They are created from the collapse of giant molecular gas clouds, often forming large and very hot stars shinning brightly in the blue-white part of the spectrum.  As they are rapidly consuming their fuel, they are also short-lived.  By ending as a super nova, they create the heavier elements beyond carbon that exists all around us.

Below is open star cluster NGC 6633, estimated to be 660 million years old (our solar system is 4.6 billion years old). The cluster is of a decent size covering just about the size of a full Moon in the night sky.  The brighter and whitish stars stand out against older and further stars in the background.

Open Star Cluster NGC 6633

Open Star Cluster NGC 6633

Younger star clusters such as the Pleiades (Messier 45) have yet to burn away their molecular gas clouds.  However there is no hint of glowing gas (nebula) with NGC 6633.

Skywatcher 80ED
Canon Rebel XTi
51x30sec (25.5 minutes) ISO 400

Cassiopeia – the W in the sky

Some constellations are easier to spot than others.  Cassiopeia with its distinctive W is visible year round in the northern hemisphere above the 34th parallel. In the image below it easily stands out from the fainter background stars.

Cassiopeia above the three line - Benoit Guertin

Cassiopeia above the three line – Benoit Guertin

The five stars drawing a W in the sky are all naked eye magnitude 3 and brighter stars, and in the image above I used a layering technique to increase the color and brightness of those stars to really make them stand out.

  1. Duplicate your base image, and set this layer to lighten only
  2. Apply a blur to the top layer(about 8-12 pixels)
  3. Increase the color saturation and brightness.  Play with the curves to brighten the bright stars, but not the background sky.
  4. Use a mask as required to filter out the bright foreground elements, such as light reflecting off a building roof-line in my image above.

Canon Rebel XTi
17mm f/4
4 x 20sec ISO800

 

Ursa Major

Ursa Major, or Big Dipper is one of the most recognizable constellation in the Northern hemisphere. People often use it to locate Polaris, the North Star.  Can you find Polaris? (Hint: upper right)

Ursa Major (Big Dipper) low in the sky in late summer around 11pm

Ursa Major (Big Dipper) low in the sky in late summer around 11pm

Canon Rebel XTi (450D)
17mm f/4
Stacking of 4 x 20 seconds @ ISO800
Post processing with GIMP

Moonlit Mountain Under the Stars

When I took the four shots to create this image below the Moon was just starting to rise above the tree-line behind me.  A full moon may be 1,000,000 times dimmer than the Sun it’s still bright enough to cast shadows and considerably light up the scene in a long exposure photo.

Over the mountain top a loose grouping of stars identified as Melotte 111 open star cluster.  These are about 40 bright stars laying 280 light years away all moving together.  It lies in the Coma Berenices constellation.

ComaBerenices_2017-08-10

Canon Rebel XTi (450D)
17mm f/4
20sec @ ISO800
The sky is a stack of 5 x 20sec.  The foreground is a single 20sec shot.

Solar Eclipse – Post Processing

With the eclipse behind us, and all the gear put away it’s time to transfer and process the images to create something memorable.  I decided to make a mosaic with some of the photos of the eclipse, as well as the visible sun spots. Click on the image below for a high-resolution version.

August 21, 2017 Solar Eclipse

August 21, 2017 Solar Eclipse

The weather cooperated and I had the right gear to get some decent photos. Before the start of the eclipse, the sun presented two observable active sun spot regions: 2671 and 2672. This helped in achieving a proper focus and gave something to observe prior to the start of the eclipse.

Sunspot Region 2671 (right) and 2672 (left)

Sunspot Region 2671 (right) and 2672 (left)

As I had installed and aligned my Vixen equatorial mount the night before, once I had proper focus with the camera, it was child’s play to start an automatic sequence of images every 60 seconds. Hence for the entire solar eclipse, it was hands-off and automated. I could simply glance once in a while at the screen or grab one of the hand-held solar viewers to look up.

58% Cover from the Montreal, Canada Location.

58% Cover from the Montreal, Canada Location.

While the effect was nowhere near that of those in the path of totality, the light level and heat did drop at the peak of the eclipse. The brightness was lower, not like when there are high altitude clouds as the shadows were still sharp and well-defined. And the sun’s rays did feel cooler, a welcomed relief from standing under the sun for the last hour.

In the end, it was a fun experience, especially with the kids. And with over 150 images taken I decided to compile them into two formats. A time-lapse video and a mosaic as seen above.

The video was actually the quickest thing done. With Microsoft Movie Maker, it takes the Canon CR2 RAW files directly and stitches them together into a video. It actually took me longer to find a suitable soundtrack to the clip.

With that experience under my belt, I’m looking forward to April 8th 2024 total solar eclipse that will pass close to home.

Telescope: Skywatcher 80ED with Thousand Oaks R-G solar film
Camera: Canon Rebel XTi (450D)
Setting: 1/1000s at ISO 100

Jupiter Below a Crescent Moon

I have to say with the wet and cloudy weather in the past two to three months I haven’t taken the telescope out for quite some time. The high humidity often produces clouds in the evening and into the night as the air cools. And with the wet spring and early summer, the mosquitoes are rather annoying.

Therefore I haven’t been actively taking part in my backyard astronomy hobby.  However a few days ago, I noticed a  crescent Moon through thin clouds, and what I thought to be Venus just below.  Grabbed the camera and took a few photos at ISO 800 66mm F5.6 1/4sec to see what type of result I could get with that.  I have to say it was hard to find the right setting, and my car’s roof was a poor tripod.

The photo below really doesn’t capture the range and subtle gradients in direct and diffused light around the Moon and the clouds, contrasting with the pin-point bright planet.

Jupiter Below a Crescent Moon (July 28, 2017) - Benoit Guertin

Jupiter Below a Crescent Moon (July 28, 2017) – Benoit Guertin

It was only a few days later when I downloaded the images on the computer and checked to confirm the planet that I was surprised that the it was Jupiter shinning so brightly.