Messier 53


In a telescope globular clusters are more interesting to observe than your open cluster because they have a distinctive shape.  Globular clusters are odd stellar objects; they are spherical clumps of stars that actually orbit our galaxy’s core.  But not the way you might think; they don’t orbit in the galactic plane, but often perpendicular to it!  This is not unique to the Milky Way, most nearby galaxies have their share of globular clusters.

Messier 53 is a nice example of a globular cluster located in the Coma Berenices constellation.  It also happens to be one of the more distant globular clusters from the Milky Way.

Globular Cluster Messier 53

Globular Cluster Messier 53

Skywatcher 80ED
Canon 400D (ISO 800)
19 x 60sec

For this one I decided to try my luck at 60sec of exposure time, and the results aren’t too bad.  I did have to throw out a few shots due to periodic error causing elongation in the stars.   Also during the stacking a used a sigma 2.3 value to discard anything that fell out of standard distribution to reduce the impact of the few bad images.

Moon – Not Waiting for Dark Skies


There’s no need to wait for dark skies to observe and photograph the Moon.  Actually most backyard astronomer don’t like the Moon as it just adds to the light pollution and prefer observing when it’s not around.

But as the Sun is setting and you’re getting your gear out, it’s hard not to take a few moments to swing the telescope over and observe the Moon.  I find the Moon so bright during the night that it almost blinds at the telescope, hence observing it under still blue skies is a great way to observe details without having to squint under darkness.  The photo below as taken at 7pm, still not under dark sky conditions.

April 15th, 2016 Moon - Benoit Guertin

April 15th, 2016 Moon – Benoit Guertin

Skywatcher 80ED
Canon 400D (ISO 400) 1/800sec
Processing with Registax6
Adding wavelet and non-wavelet layers with GIMP

The wavelet processing in Registax greatly increased the finer details on the Moon, however it also increased the noise in the blue sky background.  Therefore I opened both the pre and post wavelet pictures in GIMP and created a mask such that on the wavelet layer, only the lunar surface passed.  This was done by creating a mask based on alpha (luminance) and using BLUR to flag the entire Moon as my area of interest that I wanted to pass through.

Sunspot 2529

Sunspots on the sun come and go.  Count them for many years and you’ll soon find out that there is an 11 year periodic cycle when the solar magnetic activity peaks.  We are presently in Solar Cycle 24 and on the tail end of the double peak of 2011 and 2014.  So why would I want a solar filter when the Sun is heading into a quiet period?

Number of sunspots observed and predicted for 1995 to 2020

Number of sunspots observed and predicted for 1995 to 2020

Well, just because the number of sunspots goes down doesn’t mean that there’s not good some great observing opportunities.  Sunspot 2529 provided that perfect occasion to finally try out my new solar filter.

Sunspot 2529 (April 10, 2016) - Benoit Guertin

Sunspot 2529 (April 10, 2016) – Benoit Guertin

The above image was captured on April 10th, 2016 with on my Skywatcher 80ED with Canon 400D at ISO 200 and 1/500s.  19 frames were processed with Registax6.  Sunspot 2529 is still visible today and may be there for another week as readings indicate that it’s quite stable.

There are various types of solar filter out there.  They all essentially do the same thing which is to permit only a small percentage (roughly 0.001%) of the white light to pass through.  Solar filters are not designed to allow observation of prominence and flares, special hydrogen-alpha narrow-band pass filters are required for that,  but they do allow a view of sunspots and granulation if you happen to have sufficient focal length.  By blocking out most of the sunlight, you can then safely observer or photograph the sun.  Remember not to install your finderscope, and move the telescope away from the sun before removing the solar filter.  Your telescope is a MIGHTY strong magnifying glass.

Shopping around there are generally two types of solar filter: glass and film.  While the glass are more durable, the films offer just as good optical performance at a lower price, especially for larger aperture.

Thousand Oaks Optical R-G Solar Filter

Thousand Oaks Optical R-G Solar Filter

Normally for anything in the optical path, especially filters, backyard astronomers are always looking for the smoothest and most parallel surfaces, but for solar film, it appears that the ripples from the loose film have no effect on the image quality.

The filter that I selected is the R-G Solar Filter from Thousand Oaks Optical.  It provides a light yellow pleasant view of the sun, and works very well both visually and with the DSLR.  I enhanced the yellow in the photo of the sun above, but it’s quite close to what can be seen and photographed.

Mark your calendars for May 9th 14:57UT, Mercury will transit in front of the Sun.  The last time that happened was 2006.

Leo Triplet


Small telescopes aren’t ideal for galaxies, unless you aim to snap a picture of the Leo Triplet.  The area around Leo has many galaxies, but the three below (M65, M66 and NGC3628) are brightest and most recognized.

Leo Triplet - M66 Galaxy Group

Leo Triplet – M65 (right), M66 (below) and NGC3628 (upper left)

All three galaxies are of the spiral type, but look different because of their orientation.  NGC3628 is edge-on and the dark band in the middle are dust lanes that cut across it.  This trio is located 35 million light years away.

Skywatcher 80ED
Canon 400D (ISO 800)
32 x 30sec

Jupiter and the Great Red Spot


Yay finally got the Great Red Spot!  Throughout the years observing and taking photos Jupiter, I’ve always wondered if the darker detail I was observing was the Great Red Spot.  Based on date and time it’s possible to determine if the GRS is in view, plenty of software and tables out there for that.  But now I’ve captured my first picture of Jupiter where the GSR is unmistakable, 672 million km away.

Jupiter and the Great Red Spot

Jupiter and the Great Red Spot – March 27th, 2016

April is prime Jupiter observing time, as Jupiter reaches the meridian just before midnight.  And we happen to be at time when the Earth-Jupiter distance is at its shortest, so don’t miss out!  As it’s high in the sky, there is less turbulent atmosphere to peer through and the seeing is better.

Jupiter at 10pm mid-April

Jupiter at 10pm mid-April

The chart above is the sky due south at 10pm local time on April 15th.  And if you have a set of binoculars, camera zoom lens or telescope you’ll easily be able to see four of Jupiter’s moons all lined up next to the planet.

Above photo of Jupiter:
Skywatcher 80ED with Televue 3x
Philips Vesta 675 webcam (yes it’s old…)
Registax for alignment and wavelet
Gimp for post-processing

Crab Nebula – Need Bigger Scope


After my series of open star clusters, I decided to try my luck with the neighboring Crab Nebula (Messier 1).  A single 30s exposure show some signal, but barely above the background light pollution.

Very faint M1, just above light pollution levels

Very faint M1, just above light pollution levels

OK, lets see what the wonders of digital stacking and post-processing can do…

After stacking 28 frames, and various histogram and level stretching, I was able to get the nebula to stand out.  That’s quite an improvement from the single frame from above.

Crab Nebula - Messier 1 - Benoit Guertin

Crab Nebula – Messier 1 – Benoit Guertin

I couldn’t get any color out of it, but I believe the color images of the Crab Nebula that you often see are compositions from narrow band filters, and are “scientific colors”.

Conclusions, need to gather more light and image at a longer focal length.  Even if I increase my exposure time, as the object is small I won’t be able to get much detail out of it.  I could add a barlow to double the focal length, but would also need to further increase my exposure time.  If I try this again, I’d need a 2x barlow and at least 2 minutes exposition, and have everything autoguided.  Not there yet… Best reserved for larger and more powerful telescopes.

Skywatcher 80ED
Canon XTi (400D) ISO 800
28 x 30sec (stacked with IRIS and post-processed in GIMP)

Auriga and Its Three Bright Open Clusters

An easy target for anyone is the constellation Auriga and it’s three bright open star clusters.  It may be considered a winter constellation, but there is still plenty of time for some decent observation.  In the early April evenings , Auriga lies west about 45 degrees over the horizon.  It’s brightest star, Capella,  the sixth brightest in the night sky can easily be located.  Therefore these open clusters are easy targets for a quick star-hopping observation for anyone with a small telescope or binoculars.

Auriga in April with three bright open clusters (boxed)

Auriga in April with three bright open clusters (boxed)

My last few posts have been the photos that I’ve captured of these three Messier objects: M36, M37 and M38.  Below is a view if the boxed area from above but with the photos of the open clusters inserted at their correct location.

M37, M36 and M38 (respectively) in Auriga

M37, M36 and M38 (respectively) in Auriga

To see larger images of the open clusters, refer to my following blogs:

Messier 36 – Open Cluster in Auriga
Messier 37 – Brightest Open Cluster in Auriga
Messier 38 and NGC1907 – Open Clusters in Auriga




Messier 37 – Brightest Open Cluster in Auriga


A few weeks ago I spent some time imaging the three bright open clusters in Auriga.  After Messier 36 and 38, I now bring you Messier 37.

Surveys indicated the cluster contains about 1,500 solar masses and about 500 identified stars.  As with M36 and M38 it is located about 4,500 light years from Earth.

Messier 37 - Open Cluster in Auriga

Messier 37 – Open Cluster in Auriga – Benoit Guertin

Large research telescopes often have too narrow field of view to capture open star clusters.  This is where us backyard astronomers with our gear can shine.

Skywatcher 80ED
Canon 400D
33 x 30sec (ISO 800)