This Weekend – Best Time to See Jupiter

Posted on April 7, 2017 by Benoit Guertin

This weekend is the best time to see Jupiter of all 2017, because the planet is at opposition, meaning it is exactly opposite to the Sun and the Earth-Jupiter separation is also at its closest.

The photo below was taken during the September 2010 event and I happened to fall upon a fantastic low turbulence window in the atmosphere. Look closely and you’ll see the shadow of one of those moons on the Jupiter’s surface.

Jupiter – Benoit Guertin

Photos of Jupiter with the moons are a little tricky. Capturing the smaller moons require more exposure or gain, but at the risk of over-exposing the planet and turning Jupiter with those wonderful cloud bands into nothing more than a white sphere. It is always better to take a series of images or videos with different settings and review them at a later time on the computer. Some information on planetary imaging and processing is provided in my blog on imaging with a webcam.

Planetary imaging is all about controlling turbulence. Air turbulence whether within the optics, telescope, near the ground or high atmosphere will give you a blurry view. Hence some simple tips are:

Allow your equipment to cool down a few minutes such that the equipment temperature can stabilize and match the outdoors.
Past midnight is better as this allows time for the ground to cool especially after a sunny afternoon, reducing convective currents.
Wait until Jupiter is high in the sky, that way there is less atmosphere between you and Jupiter. By looking straight up, you will be looking through a smaller “air column”.

A good time will be on April 10th when the Moon will next to Jupiter. See the sky chart below showing the southern part of the sky at 10pm EDT. The planet will track west as the night advances.

April 10th 2017 Sky Chart

Fast Moving Comet Before Sunrise

Posted on February 9, 2017 by Benoit Guertin

If you are able to get out of bed early and the sky is clear, equipped with binoculars you should be able to catch a fast-moving comet as it swings by Earth at about 32 lunar distances over the next few days. The best time is just prior to sunrise as the comet will be higher in the sky in the East. Use Jupiter as well as bright stars Vega and Arcturus to get your bearings. With each day the comet will rise earlier and will appear higher in the sky as the chart below shows; comet position at 5am for the next week. However it will diminish in brightness as it moves away from Earth on after February 11th.

Comet 45P over the next few days starting Feb 10th.

This isn’t the closest a recording of a comet passing near Earth, but it does make it to the 8th spot since modern observation and have been keeping track of near Earth objects (1950). Back in August 15 2011, it happen to pass even closer, only 23 lunar distances, making it also the 5th closest comet approach.

With a storm system moving up the eastern edge US and Canada, my chances of getting any clear morning sky is pretty slim…

Downloadable PDF Sky Chart: 45p_feb2017_chart

Tomorrow Evening: Moon, Mars and Venus

Posted on January 30, 2017 by Benoit Guertin

Great photo opportunity tomorrow evening, January 31st, with a thin crescent Moon in a close formation with Mars and Venus. As the sky darkens simply look between South-West and West and you won’t miss them. However don’t wait too late, by 9pm they will have disappeared below the horizon.

Early Evening Sky (7pm) – Look WSW for this close formation

The Moon will be a thin crescent. Here it is as photographed of the Moon tonight at 5:40pm just a little less than 3 days old.

Crescent Moon – 30-JAN-2017 (5:40pm)

No high-resolution photo for this one. Took it quickly through an open window simply by hand-holding the telescope, and using Venus to quickly find focus through the camera view-finder.

Skywatcher 80ED
Canon XTi (1/50s at ISO400)
Registax6 to align, stack and wavelet on the best 3 frames (out of a dozen)

Challenge for the next 2 days: Comet

Posted on January 4, 2017 by Benoit Guertin

My challenge for the next two days (Clear Sky Chart is predicting clear skies) is to observe and capture comet 45P/Honda-Mrkos-Pajdusakova. It should be relatively easy to locate by hopping from Venus then down the bright stars of Capricorn starting with Delta, Gamma, Iota and ending with Theta. Then half a degree to the left of Theta Cap is magnitude 6 star HD201057. Comet 45P at magnitude 7 should be just next to that star.

The challenge will be its position low near the horizon, I may have obstructions before it sets. And the twilight may not be dark enough for a magnitude 7 object. The viewing time window will be quite small…wait for darkness and it will fall out of view.

Location of comet for January 5th 5:30pm EST

No need for telescope, it’s also a binocular object.

45P is the 45th periodic comet (Halley being the 1st identified periodic comet) with a 5.3 year period. Its orbit swings from just past Jupiter to in between Mercury and Venus.

Easily Locate Neptune on December 31st

Posted on December 28, 2016 by Benoit Guertin

December 31st will be your opportunity to easily locate and observe Neptune with a telescope as it will be within 1/3 degree of Mars low in the western part of the Sky. Mars will present a reddish magnitude 1 disk while Neptune will be much smaller, essentially a dimmer magnitude 7.8 dot. Large telescopes should reveal the blueish hue of Neptune when placed slightly out of focus.

Neptune and Mars 1/3 degree – December 31 (1 degree circle)

In the image above I’ve marked magnitude 7.9 star just outside the 1 degree circle to assist in the orientation.

However don’t wait too late in the evening, best may be shortly after 7pm once the Moon is below the horizon. Starting from the horizon you’ll able to easily locate bright Venus and about 10 degrees above will be Mars and Neptune. Bright stars Fomalhaut and Altair will be located east and west along the horizon.

Neptune Mars and Venus setting in the West – December 31 (7pm)

Auriga and Its Three Bright Open Clusters

Posted on April 2, 2016 by Benoit Guertin

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)

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

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

Orion Constellation and Open Clusters

Gallery

Posted on December 12, 2015 by Benoit Guertin

This gallery contains 1 photo.

Open clusters around Orion. Continue reading →

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Observing Pluto – What Does it Take?

Posted on October 21, 2015 by Benoit Guertin

With New Horizons‘ flyby of Pluto and all the great images the spacecraft has been returning I’ve wondered: Is it possible to observe Pluto from one’s backyard? Personally I’ve never bothered trying for Neptune and beyond as I knew my small 80mm aperture telescope would not be up to the task. Nevertheless I looked up Pluto’s apparent magnitude and found that it varies between 13.6 and 16.3 due to its elliptic orbit around the Sun. It’s last closest approach (perihelion) was September 1989, and unfortunately Pluto is currently distancing itself for its 248 year journey around the Sun therefore slowly dimming, sitting right now at apparent magnitude 14.

Pluto as viewed by New Horizons during flyby (14 July 2015) – NASA

What size of telescope does it take to observe an apparent magnitude 14 object? Based on the theoretical limits it should be possible to make visual observation with a 10in aperture telescope, but most would say you need a 12in if you plan to observe with an ocular. Of course, equipped long exposure cameras you can have a smaller telescope, but a high focal length would be preferred to reduce to better pick it out from the background of stars. And I’ve managed to pick up mag 14 stars in my photos with the Skywatcher 80ED with 60sec exposures. Therefore Pluto should be accessible to backyard astronomy. Note that at Pluto’s size and distance it shows up as a light point and not a sphere like the other planets.

Up to the challenge? Middle of November will be a great opportunity to locate Pluto as it will swing within 1deg of Ksi 2 Sagittarius, a magnitude 3.5 star. In the June edition, Sky & Telescope created a great star-chart to locate Pluto until December 2015. Good Luck!

Click on image for Sky & Telescope Pluto 2015 Sky Chart

Reference: Sky & Telescope

Comet 67P/Churyumov–Gerasimenko : Where is it, and where will it be.

Posted on November 14, 2014 by Benoit Guertin

In my previous post I’ve mentions that coment 67P/Churyumov–Gerasimenko is currently between the orbits of Jupiter and Mars, on a trip towards the Sun. While some comets take decades to become visible again this one has an orbital period of 6.44 years, therefore a frequent visitor. That was one of the selection criteria for the target comet: short orbital period such that it did not take too much fuel or planetary gravity assist to intercept.

On August 13th it will be at it’s closest position to the sun (perihelion), therefore brightest and a good time to observe. Afterwards it will be swinging back out towards Jupiter on its elongated orbit. For people in the Northern Hemisphere, the best time to observe comet 67P will be after this August date. Below is a chart showing that the comet will be visible in the early morning starting in June 2015, and will be visible at higher altitudes in the sky throughout the following months.