Wednesday, January 31, 2018

Super Blue Lunar Eclipse

Living here in the USA, things have been a bit surreal over the past year.  As the Great Orange One (GOO) that occupies the office reserved for President has done his best to divide our citizenry and alienate us from the rest of the conscious world, it is sometimes difficult to remain optimistic about our future.  Fortunately, there are events that remind us of our place in the universe; and despite the deep divisions that are being cultivated by the GOO, there are greater forces at work that serve to unite us here on Earth.  There is something about seeing the solar system in motion in a way that we do not witness frequently, that seems to recharge my desire to make the world a better place.

Early this morning we were treated to a widely publicized total Lunar Eclipse.  This eclipse occurred on the second full moon within a calendar month (a "Blue" moon), and also at the time of perigee, when the moon is at the closest point in its elliptical orbit around the Earth (the "Super" moon).  The occurrence of a "Super Blue Lunar Eclipse" is indeed rare, with the last one occurring in 1866, one hundred and fifty two years ago! I observed the eclipse from work, (The Mount Lemmon SkyCenter) where we were providing a live stream of the eclipse for NASA.

The image at left was taken with my Canon 6D and a 70-200mm lens set to 100mm, just before sunrise.  You can see the eclipsed moon hanging in the dawn sky with Picacho peak in the distance at lower right (along with I-10 traffic just in front of it).

Below is a collage of some of the images I captured during the eclipse, using my Canon 6D and my Stellarvue 90mm refractor.  Remember to click to enlarge (perhaps twice if your browser automatically resizes images to fit the window)
So you missed the eclipse and are wondering when the next lunar eclipse is here in AZ? The next eclipse in Tucson will be on January 20, 2019 starting at 7:36 PM local time.

Finally, my friend Roger who observed and photographed the eclipse with me, had a little fun with my image above...

Monday, January 1, 2018

International Space Station Transit

Happy New Year and welcome 2018!  There is much to celebrate!!

It is fitting that 2018 started off for me with an astronomical adventure, as it provided some fodder for a blog post...and in addition, New Years Day is the anniversary of this blog!  It all began here, in Googleland, on January 1, 2010.  While I have trailed off in the frequency of blog posts, my enthusiasm for astronomy remains strong.  The icing on the cake, is that today is the 22nd anniversary of my marriage to the love of my life, Beth.

As for the astronomical adventure, it happened that there was a transit of the International Space Station across the disc of the Sun as seen from central Tucson today.  This is the third time I have observed a transit of the ISS across the Sun, and you can read about the first adventure here, and the second here.

Today, I headed out to Himmel Park in central Tucson with my friends Jerry and Travis and set up my TEC 140 refractor with a Herschel Prism.  At the last minute I decided to use my Canon 6D to record video, instead of attempting to 'burst shoot' the transit.  This would take a lot of stress out of having to touch the camera and capturing an event that lasts approximately 1 second!

Without writing a novel, it was a success!  I am posting the original video at the bottom of this post, and I also created a composite of 32 individual frames showing the transit.  You can see in the composite image below that we were not perfectly centered under the ISS shadow, but we were very, very close.

Click the image to enlarge

To appreciate the scale here, consider that the Sun is about 93 million miles away and the ISS was approximately 421.5 miles downrange from me during the transit!  Because the ISS is so close, one must be on a very narrow ground track of the ISS' shadow in order to have the transit appear centered on the Sun.  Today's transit lasted 1.4 seconds on the center-line.

How fast does the ISS orbit?  It orbits the Earth in approximately 92.6 minutes, which results in an apparent ground speed of 7.885 km/second (4.9 miles/second)!  The ISS is also fairly small-  It's dimensions are approximately:
Length 72.8 m (239 ft)
Width 108.5 m (356 ft)
Height ≈ 20 m (66 ft)

The distance of the Space Station today, coupled with it's actual size, translates into an apparent angular diameter of 41 arcseconds- and the Sun is about 1800 arcseconds in diameter.  So the ISS is about 2.2% of the apparent diameter of the other words, you could fit about 44 ISS's across the Sun's face today.  You can now appreciate why a video capture is the easiest.

Here is the short close attention as the transit is only 1 second!  Watch it full screen for easier viewing.

Saturday, May 6, 2017

Zodiacal light and a bolide

Going through some pictures this morning and I found one that I took in Portal a couple weeks ago that I thought was worth sharing.  Not long after sunset I was setting up my camera for some late night attempts at the Summer Milky Way, and took the picture below as a test shot to make sure I had the focus set properly.  You can see the setting winter Milky Way, intersected by the zodiacal light, and in the lower right is a very bright bolide.  A bolide is a large meteor that is exploding in the atmosphere (they are often referred to as fireballs).  You can see the green color, which was easily visible to the naked eye.  Unfortunately, this one was on the horizon and not overhead-  Had it been overhead the streak would have been much longer, it would have appeared brighter (less atmospheric extinction of light), and there may even have been a visible vapor trail.

Monday, April 24, 2017

Portal to the stars

Just back from another weekend adventure out to the dark Skies of Portal, AZ.  Seems that my blog is slowly turning into the Portal any event, below is an image of the Milky Way just after it cleared sufficiently above the horizon for a picture.  In this image we are looking toward the center of our galaxy, in the constellation of Sagittarius.

The green glow just above the horizon is air glow- light being emitted by Earth's atmosphere.  This is from several sources, such as the recombination of atoms which were ionized by the sun during the day, light caused by cosmic rays striking the upper atmosphere, and energy emitted by the combining of nitrogen and oxygen in the upper atmosphere.

While the entire sky has air glow (and as a result it is never truly dark), the glow is most obvious about 10-20 degrees above the horizon.  This is because the glow is subtle, and we are looking through about twice as much atmosphere looking across the horizon than when peering overhead.  (We do not notice the air glow on the horizon due to atmospheric extinction of the light on the horizon).

Tuesday, April 4, 2017

Having fun at work

I really do have a great job-  I always tell folks that somehow I married a great hobby with a lot of administrative experience at the University...and now I get to worry about the budget and work with telescopes at the same time!  Two weeks ago we held two first ever events at the SkyCenter- a DSLR milky way and star trail workshop and a Messier Marathon.   Here is a single shot of the summit as the milky way was rising on March 25th-

While I had to work and did not 'participate' in either event, I did manage to squeeze off a few pictures of my own during the night- First, this is a single 20 second exposure of M 13, the Hercules globular cluster, taken through the 24" Phillips telescope using my Canon 6D.  I was impressed with the image out of the camera, so I decided to try and process it a little using Photoshop...and while I know the color of the stars is a little saturated, I still like the result.

In addition, I took a 30 second exposure of the M 57, the Ring Nebula in Lyra.  The image below is a 100% crop, and my colleague (and professional photographer) Sean Parker worked the processing a bit to bring out the galaxy (IC 1296) nearby the ring...but the ring itself is very much what the Canon delivered.

Final image from the weekend, is an exposure I took inside the dome of the 32" Schulman Telescope during a break in the Messier Marathon while guests were waiting for the summer constellations to rise a little higher.  It seems bright in the dome, but consider all the lighting is coming from red led lights that illuminate the steps leading into the dome!

Hey, 2 blog posts in two weeks!

Tuesday, March 21, 2017

Winter Milky Way

Time for what is becoming a quarterly tradition...a blog post!

In February, I made a trip to the dark skies of Portal, AZ with my good friends, "The League of Extraordinary Ordinary Observers" for our regular gathering of opinions, half-baked ideas, conspiracy theories, and of course telescopes.  We had our usual good time and saw some wonderful celestial sights.

I have posted pictures before of the summer milky way from Portal (see my previous post, for example...remember, quarterly tradition!), yet I do not believe I have ever captured a decent photo of the winter milky way.  One reason for this is that we tend to take our trips when it is warmer than February and the other is that the winter milky way is much fainter than the summer.  To explain quickly, in the summer night sky we are looking toward the central bulge of our galaxy in Sagittarius, and the center of our galaxy contains a much higher density of stars.  In the winter night sky, we are looking out away from the center of our galaxy and our view across the plane of the galaxy is not nearly as bright as when we look inward toward the center.

Below is an image of the winter milky way, that I captured in Portal.  It is a stack of 3 individual frames and is to me, quite striking.  Not only can you see detail and dust lanes in the plane of our galaxy that are invisible anywhere near a city or town, but you can also see several subtle (and I mean subtle) pink nebula such as The California Nebula, Barnard's loop, The Rosette Nebula, etc.  Be sure to click the image to enlarge.

These nebula would be more visible if my camera was astro-modified to be more sensitive in the red, however, I am impressed that the Canon 6D and Rokinon 14mm combination caught them at all.  The (distorted) bright star lower left is Sirius and the double cluster in Perseus is visible in the upper right, just to give you a sense of how wide this shot is.  I would be remiss if I did not mention the zodiacal light reaching from the lower left up through the Pleiades into the milky way.  The Zodiacal light is sunlight, scattered by dust in the plane of our solar system left over from the time of our solar system formation.  It is visible in dark skies after sunset and before sunrise, and is brightest in the spring and fall.

The other fun thing that occurred during the trip to Portal, is that I took a day to drive to Socorro, NM where I met a fellow amateur astronomer from whom I was purchasing a dobsonian telescope.  It is my first dob after all these years and it reminds me I need to update the equipment page of this blog as the only telescope that I currently have listed on that page is my TEC 140!  In any event, at left is the new scope and I hope to share some adventures with it soon...In case you are wondering, it is a 12.5" Obsession Dobsonian, with a mirror by OMI.