April Lyrid Meteor Shower

Posted on April 18, 2023 by Benoit Guertin

If you’re a fan of shooting stars, and want to catch bits of Comet Thatcher burn up in the atmosphere, you won’t want to miss the Lyrid meteor shower this April. The Lyrids are one of the oldest known meteor showers, dating back to ancient China and they can produce up to 20 meteors per hour at their peak. The meteor shower is caused by leftover debris from Comet Thatcher, a long period comet (415 year) that has only been observed once since discovery in 1861, and is scheduled to return no earlier than 2283.

But how can you enjoy this celestial spectacle if you live in the city, where light pollution can wash out the night sky? Here are some tips to help you catch a glimpse of the Lyrids this year.

The best time to watch the Lyrids is between midnight and dawn on April 22nd to 23rd, when the shower reaches its maximum activity. However, you can also see some meteors a few days before and after this date, as the Earth passes through the debris trail left by comet Thatcher.
The Lyrids appear to radiate from the constellation Lyra, which rises in the northeast after sunset and climbs high in the sky by dawn. You don’t need to look directly at Lyra to see the meteors, but it helps to find a spot where you have a clear view over the eastern horizon.
To avoid light pollution, try to get away from bright streetlights, buildings, and cars. You can also use an app like Dark Sky Finder or Clear Sky Chart to find a dark location near you. If possible, drive or bike to a park, a hill, or a rural area where you can see more stars. As luck would have it the Moon, only at 10% illumination, will set just before midnight, removing one pesky light source.
Once you find a good spot, let your eyes adjust to the darkness for at least 15 minutes. You don’t need any special equipment to watch the Lyrids, just your eyes and some patience. Dress warmly, bring a blanket or a chair, and maybe some snacks and drinks to keep you comfortable.
If you’re not too sure where to look, the bright star Vega should help guide you, located East about 45 degrees over the horizon.
You can also setup a camera on a tripod with a wide angle lens, taking multiple long exposures of about 20 seconds. Place the radiant of the meteor show on the edge of the frame to capture longer trails.

Enjoy the show! The Lyrids are known for producing bright and fast meteors, some of which can leave persistent trails in the sky. You might also see some fireballs, which are very bright meteors that can light up the whole sky.

The Lyrid meteor shower is a wonderful opportunity to connect with nature and marvel at the beauty of the cosmos. Don’t let the city lights stop you from experiencing this amazing event. Happy stargazing!

Photography – 2023 Venus and Pleiades Conjunction

Posted on April 16, 2023 by Benoit Guertin

I’m sharing with you a photo I took of the recent Venus and Pleiades conjunction. The closest approach was on April 10th, but I had to wait until the 12th for a clear sky. It was a pretty sight to see the bright planet and the star cluster so close together in the night sky. I used my Canon 80D and a telephoto lens to capture this image. Here are some tips on how I did it:

Because I was going to take a long exposure and wanted round starts I used my equatorial mount and installed the camera with a clear view of the western horizon.
I set the camera to manual mode, the aperture to f/4.5, the shutter speed to 5 seconds, and the ISO to 1600.
I zoomed in with 135mm of focal length for the desired framing and focused on the bright stars using live view. Initially selected a bright star, and then moving to more dim ones for final focus adjustments. I made sure that both Venus and the Pleiades were nicely in the frame.
To take a photo without camera shake I used the 10sec delay and then checked the histogram to verified that the result is not overexposed.
I then went into the interval setting of the camera to take multiple photos, around 70 in total.
I imported the photos into Deep Sky Stacker for the registration and stacking of the photos.
Then opened the resulting photo over to GIMP for final adjustments like white balance, levels, color saturation, background gradient removal and noise reduction.
I exported the final image as a JPEG. Here it is, click to open full image:

Venus and Pleiades Conjunction April 12, 2023

I was hoping to capture a hint of the nebulosity within the star cluster, but I guess 5 seconds exposures, even when integrated to 6 minutes is not enough to capture that fainter detail. It was around 8:00pm when I took the photos, the sky was not fully dark, making the use of exposure above 5 seconds too bright. However I did manage to capture the colors of the stars down to magnitude 9.

I hope you enjoyed this post and learned something new. If you have any questions or comments, feel free to leave them below. Thanks for reading!

Canon 80D
135mm F4.5 telephoto lens
Individual photos: 5 seconds at ISO 1600
6 minutes total integration time
Vixen GP Equatorial Mount (untracked)
Registration and stacking with DSS
GIMP for final adjustment

April 11, 2023 – Venus Next to the Pleiades

Posted on April 10, 2023 by Benoit Guertin

If you are a stargazer, you might want to mark your calendar for April 11, 2023. At dusk, look west, you will have a chance to see Venus shining bright just 5 degrees left of the Pleiades, a beautiful star cluster also known as the Seven Sisters. Venus is the brightest planet in the sky and it will be easy to spot with the naked eye or binoculars. If you have a clear sight of the horizon and head out early enough, planet Mercury will be visible low in the sky and at a prime time for viewing at 19 degrees from the sun.

Conjunction of Venus with the Pleiades on April 11, 2023 — Venus next to the Pleiades on April 11, 2023 after sunset

The Pleiades, also known as the Seven Sisters, is a famous star cluster in the constellation of Taurus. It is one of the brightest and most easily recognizable clusters in the night sky, visible to the naked eye in both hemispheres. The Pleiades consists of about 1000 stars, but only a few are visible to the unaided eye. The brightest stars are named after the mythological daughters of Atlas and Pleione in Greek mythology: Alcyone, Asterope, Celaeno, Electra, Maia, Merope and Taygeta.

Venus just 5 degrees left of the Pleiades

But that’s not all. Venus is also approaching its greatest elongation, which means it is farthest from the sun on the sky’s dome. This will happen on June 4, 2023, when Venus will be 46 degrees east of the sun and will set about three hours after sunset. At that time, Venus will be 49% illuminated and will appear as a first quarter phase through a telescope.

Greatest elongations are important events for observing the inner planets such as Mercury and Venus. They orbit closer to the sun than Earth. Therefore, it always appears near the sun when the sky is still blue and bright or lower over the horizon, and never overhead at midnight.

If you want to learn more about Mercury or Venus and its position in the sky, you can check out some online resources such as EarthSky.org or SkyandTelescope.org. They have detailed information and charts about Venus’s movements and appearances in the sky. You can also use a free online planetarium program such as Stellarium (what I used for the above screen captures) to see how Venus looks from your location at any time.

May Lunar Eclipse (Yes a Super Moon)

Posted on May 26, 2021 by Benoit Guertin

I hope that some of you will be taking a few minutes this evening to head outside and glance up at the Moon. Not only is tonight a “Super Moon” but depending where you are, you may find the Moon taking on a red hue due to a lunar eclipse.

For tonight’s event, those around the Pacific rim are best located to see the lunar eclipse. On the east coast of North America you might spot the start of the eclipse as the Moon sets in the early morning.

Location of best viewing. *Leah Tiscione / S&T; Source: USNO*

Even if you are not in a favorable spot, take the time to look at the Moon. There’s this timeless element to it, knowing that it’s been there for millions of years and will continue to be there for many more.

It is also accessible to everyone, no matter how light polluted your sky happens to be.

The best way to see the Moon is with nothing else but your two eyes. Resist the urge to attempt a photo with your phone. That will only end in frustrations. All photographs of the Moon are heavily processed because it’s very hard for a camera to handle both the brightness of a full Moon and the black of the nuit sky, or the glowing halo shining through the thin clouds. And when you do get the brightness under control, all the subtle details of the Moon’s surface is lost. Your eyes are better equipped to handle the large range of brightness and the resolution to really enjoy the sight.

Two separate shots and 15 minutes of processing is required for this, yet your eyes can easily see the details in real time.

2021 Snow Moon

Posted on February 26, 2021 by Benoit Guertin

2021 Snow Moon

February’s Snow Moon

Posted on February 25, 2021 by Benoit Guertin

There’s been lots of attention over Mars this past week. I can’t really blame all the media coverage, the Mars 2020 Perseverance EDL to the Martian surface was really cool and a great feat for NASA. I enjoyed watching it live on the NASA YouTube feed. But this weekend let’s turn our attention to the Snow Moon; the only full moon in February.

The full moon will occur at 3:17am Saturday, so tomorrow evening will be the best time to catch it. There’s nothing particularly special about this full moon, not a Blue Moon (second Full Moon in the month) or “Super Moon”. The name Snow Moon comes from the Farmer’s Almanac as February is normally the month that receives the most snow in North America.

The great thing about full moons is that you don’t need to stay up all night and wait outside in the frigid cold to see it. At this time of year, in the Northern hemisphere, the Moon is visible for more that 12 hours a day.

If you’re tempted to photograph the Snow Moon, leave the mobile phone behind, it’ll just give poor results and you’ll end up frustrated with frozen fingers. Instead just enjoy the view, paying close attention to the various dark “seas” spanning the lunar surface.

If you do try taking a picture, grab a DSLR or compact camera with manual mode. Set the ISO around 200 and the focus to manual. Your shutter speed should be high, around 1/800s; a full moon is surprisingly bright. You’re get better results by slightly under-exposing your shot. If you have a tripod, use it, else try to steady yourself on something (railing, chair, car roof, etc..) Subtle movement can easily ruin the details in you photos.

Clear skies!

Manually Processing Comet Images

Posted on December 28, 2020 by Benoit Guertin

Looking back, the “Great comet of 2020″ C/2020 F3 NEOWISE was a fantastic sight and well worth the 3am alarm to snap some photos back in July. But comet images are notoriously difficult to work with. Should I also add that in older times, comets were often seen as a bad omen, the bearer of bad news? Cough, cough COVID-19 cough…

Anyways, back to astronomy… There are essentially two types of photo registration (alignment) software out there: 1) Deep Sky which uses pin-point stars to perform alignment; 2) Lunar/Planetary uses the large “disk” of a planet or Moon to align based on surface details.

So when you capture long wispy comets like the RAW image below, software like DSS or Registax just can’t cope.

RAW image : Canon 80D 300mm f/5.6 5 seconds exposure at ISO3200 (09-jul-2020)

I turned to standard photo-editing software for a manual alignment and stacking. This is essentially opening one “base” image and then adding a 2nd image as a new layer. I change that 2nd layer to be overlaid as a “Difference” and manually align this 2nd layer to match the base layer. Once that is done I change the layer mode to Addition, and then hide this 2nd layer. Repeat the steps for a 3rd, 4th, 5th, etc. layers until you’ve added all your images. Always aligning with the “base” image to ensure no drift.

If you simply add all those layers up, you will get one very bright image because you are adding pixel intensities. You can do that and then work with the Levels and Curves to bring it back down, or if like me, working with GIMP, then use the Py-Astro plug-ins to do the merging and intensity scaling in a single step with a Merge all layers. Py-Astro can be downloaded here. I haven’t explored all that the plugins have to offer, that will hopefully be in another blog.

Stacking 11 individual frames results in an improvement over a single RAW image (image below). With the stacked image, I’m able to work with the intensities to darken the sky while keeping the comet tail bright.

After merging 11 images manually aligned in GIMP

However the sky gradient is pretty bad, due to the camera lens and because at 4am the sun is starting to shine on the horizon. So off to IRIS to correct the background gradient. From GIMP I save the files as a 16BIT FIT that I can use in IRIS. For steps on how to do this, see my blog about how to remove the sky gradient.

After a quick spin in IRIS, I’m back in GIMP for final color and intensity adjustments, I boosted the BLUE layer and adjusted the dark levels for a darker sky.

C/2020 F3 NEOWISE from 09-JUL-2020 by Benoit Guertin — Final Processed image of C/2020 F3 NEOWISE from 09-JUL-2020

“7 Minutes of Terror”

Posted on December 26, 2020 by Benoit Guertin

The folks at JPL created a short film showcasing Perseverance’s critical descent phase for the Mars landing. If everything goes according to plan, we shall have a new rover on Mars at 3:40pm EST on February 18, 2021.

Perseverance is currently “cruising” at 84,600km/h through space with Mars as a target. To give you an idea of what kind of speed that is, here are a few benchmarks:

The fastest commercial jet: the Concord flying at Mach 2.04 is just under 2,200km/h
Space Shuttle re-entry speed: 28,100km/h
Voyager 1, leaving our solar system : 61,500 km/h
Parker Solar Probe (fastest man-made object) : +250,000km/h

Perseverance was launched on July 30th, 2020 from Cape Canaveral Air Force Station, Florida, on top of a Atlas V-541 rocket.

Animation of Mars 2020’s trajectory around Sun, Data source: HORIZONS System, JPL, NASA

The only way the rover will be able to decelerate from its current cruising speed is by plunging into the Martian atmosphere at the right angle and using the atmospheric friction to slow it down. That “7 minutes of terror” is the time the rover will spend on re-entry, from approaching Mars at the right angle, to landing in the desired spot on the Martian surface.

Lots of steps need to go right, timed correctly to have a successful landing. Only 22 of the 45 landers sent to Mars have survived a landing. The US is by far the country with the most success (sorry Russia, you’re space program is awesome, but you suck at landing on Mars)

Glancing up at the night sky that February 18, 2021 evening will be very easy to spot Mars, but also the Pleiades star cluster (Messier 45). Mars will be about 5 degrees north of a almost half-illuminated moon. And if you keep looking higher up by 10 degrees you’ll see the famous open star cluster nicknamed the Seven Sisters, also used as the Subaru emblem.

C/2020 F3 (NEOWISE) Thanks for Swinging By

Posted on August 28, 2020 by Benoit Guertin

I live in a heavily light polluted city, therefore unless it’s bright, I won’t see it. But boy was I ever happy with the outcome of this comet! In my books C/2020 F3 (NEOWISE) falls in the “Great Comet” category, and it’s by far the most photographed comet in history because it was visible for so long to folks on both sides of the globe.

My last encounter with a bright comet was in 2007 with periodic 17P/Holmes when it brightened by a factor half a million in 42 hours with this spectacular outburst to become visible to the naked eye. It was the largest outburst ever observed with the corona becoming temporarily the biggest visible object in the solar system. Even bigger than the Sun!.

Comet 17P/Holmes November 2, 2007 (Benoit Guertin)

So when the community was feverishly sharing pictures of the “NEOWISE” I had to try my luck; I wasn’t about to miss out on this chance of a lifetime.

I have to say that my first attempt was a complete failure. Reading up when it was the best time to try to photograph this comet most indicated one hour before sunrise was the right time. So I checked on Google Maps where I could setup for an un-obstructed view of the eastern horizon (my house was no good) and in the early morning with my gear ready at 4am I set off. To my disappointment and the “get-back-to-bed-you-idiot” voice in me, it didn’t work out. By the time I got to the spot and had the camera ready, the sky was already too bright. No comet in sight, and try as I might with the DSRL, nothing.

Two evenings later and another cloudless overnight sky I decided to try again, but this time I would make it happen by setting the alarm one hour earlier: 3am. That is all that it took! I was able to set-up before the sky could brighten, and then CLICK! I had this great comet recorded on my Canon SD memory card.

Comet C/2020 F3 (NEOWISE) in the dawn sky on July 9th. (Benoit Guertin)

I didn’t need any specialized gear. All it took was a DSLR, a lens set to manual focus, a tripod and 5 seconds of exposure and there was the comet. I snapped a bunch of frames at different settings and then headed back home to catch the last hour of sleep before starting another day of work. Lying in bed I felt like I had accomplished something important.

As the comet swung around our Sun and flipped from a dawn to a dusk object I decided I should try to photograph it once again, but this time with the Skywatcher 80ED telescope. At that point, the comet was dimming so every day that passed would be more difficult. It was only visible in the North-West horizon at sunset, which meant setting up in the front the the house, fully exposed to street lights. Not ideal, but I had nothing to loose trying.

Setup in front of the house, fully exposed to street lights to catch the comet.

I used our tree in the front yard to act as a screen and was able to locate and photograph this great comet. Polar alignment wasn’t easy, and when I had the comet finally centered and focused with the camera, overhead power lines were in the field of view. I decided to wait out 30 minutes and let the sky rotate to the lines out of the view. Besides, it will get darker anyways which should help which the photo. But I also realized that my “window” of opportunity was small before houses would start obscuring the view as the comet would dip to a lower angle with the horizon.

C/2020 F3 (NEOWISE) July 23, 2020 – Skywatcher 80ED (Benoit Guertin)

I’m sure in the years to come people will debate if this was a “Great Comet”, but it my books it’s definitely one to remember. It cemented with me the concept that comets are chucks of “dirty ice” that swing around the sun. Flipping from a dawn to dusk observable object after a pass around the Sun is a great demonstration of the elliptical nature of objects moving in our solar system.

Now waiting for the next one…

The Great Comet of 2020 That Never Was

Posted on April 19, 2020 by Benoit Guertin

Back in March, the astronomy crowd was buzzing about a possible”naked-eye” comet expected in late May 2020. Comet C/2019 Y4 (ATLAS) was first detected at the tail end of December as a very dim magnitude 19.6 object and by mid-March it had brighten to an easy telescope target magnitude of 8. Those not familiar with the magnitude scale, going from 19.6 to 8 is not a doubling in brightness, but around a 4000 times increase!

That dramatic increase in brightness help fuel the hype for the Great Comet of 2020, and there were two other factors that got people excited:

It would be visible at dusk from the Norther Hemisphere, hence within easy viewing to much of the world population.
It was following a similar orbital path as the “Great Comet of 1843“, suggesting that it was from the same original body and could potentially provide the same viewing spectacle. That 1843 comet was visible in daytime!

Well all that went south when the comet’s breakup was observed in late March after peaking momentarily at magnitude 7. It began to dim, along with any hopes of a Great Comet repeat. Below is a graph showing the the original (grey line) and revised (red) comet brightness forecast (dots being observed measurements) on this chart created by Seiichi Yoshida (comet@aerith.net)

Comet C/2019 Y4 (ATLAS) Brightness - Copyright(C) Seiichi Yoshida

Comet C/2019 Y4 is expected to make its closest approach to the sun on May 31st, however most experts believe it will disappear (disintegrate) before that date. Seeing that I had a small window of opportunity to capture the comet I decided to try my luck last Saturday evening.

Below is an extremely processed (and ugly) image that I got by combining 25 photos (15 seconds each at ISO 3200) using my Skywatcher 80ED scope. The photo just about makes out the distinctive blue-green hue and elongated shape of a comet. It is around magnitude 10, very diffuse and about 147 million km away from us the day this photo was taken.