Thursday, September 28, 2017

Northern Lights 9/28/2017

  Although the Sun is quickly approaching the minimum activity portion of its 11 year cycle, it still can send streams of particles that interact with Earth's magnetic field.  Last night that interaction produced a respectable auroral display for the mid-latitude areas of the US.  The problem that I had to deal with was a persistent layer of low level clouds that didn't dissipate as promised.  Despite less than favorable conditions I set my camera up at work and let it take 6-second long exposures all night long.  The photo above was taken during the peak of the activity around 3:30 AM.

Thursday, August 24, 2017

Black Hole Sun

    In the two days that I spent in Eastern Oregon leading up to Monday's total eclipse, I asked a few locals where they intended to view the eclipse.  I was kind of surprised that some of them planned to view from their homes just outside of the path of totality.  Although 99.7% rounds up to 100%  and that is adequate in most situations, it doesn't compare when it comes to eclipses.
    When 99.7% of the Sun is covered you're still looking at the Sun.  When 100% of the Sun is covered you're able to see the elusive corona and prominences the filaments of particles attempting to escape the solar surface.
     The eclipsed Sun is comparable in brightness to a Full Moon.
    During the 1 minute 56 seconds of totality I was frantically operating and adjusting 2 cameras, one with a 500mm lens and the other wide angle 28mm lens.  During the fleeting moment of the 'diamond-ring' effect as the last (first) ray of sunlight disappears (appears)  at the beginning (end) of totality, the Sun and Moon combination looks like a ring of corona with one bright point shining like a diamond. At those opportunities I should have been manning the telephoto equipped camera, Instead I only (accidentally) caught it with the wide field camera.
  Crop of photo above shows a diffraction obscured 'Diamond-ring' effect.
     A little longer exposure shows the sparsely illuminated foreground during totality.
   A crop of that photo shows the star Regulus to the lower left of the eclipse. Click on photo below to see it.

   Another neat effect observable during the partial phases before and after totality is that light passing through a small aperture reveals an image of the light source.  Among our group of eclipse watchers was my niece Danielle who's sunhat projected a multitude of mini eclipses on her shoulder. 

Monday, August 21, 2017

Total Eclipse 8/21/2017

    Disclaimer : These photos do no justice to the spectacle created by the Moon blotting out the late morning Sun.

  It started innocently enough as a small notch formed on the upper right edge of the Sun.

   The bite got bigger....

....until our local star showed a fat crescent.

   It progress until only a sliver remained
    After the last ray of sun shined through a deep crater on the Moon's rim creating a diamond ring effect(not pictured), the elusive solar corona appeared.  A close look at the photo below reveals a red promenience at the same position that the moon's transit started.
  A longer exposure shows the star Regulus (circled) to the lower left of the eclipsed Sun.

He had to stay home because he couldn't pass the eclipse safety test.

Friday, August 11, 2017

Perseid Meteor Shower 8/11/2017

   This year's Perseid Meteor Shower is set to peak over the next two nights.  Although the peak rate of 60/hour is spread out over the wee hours of Saturday and Sunday  much lower rates can be detected over a period of 3 weeks surrounding this weekend.
    At 2:00 this morning I set up my camera on the back deck and shot over 700 consecutive 5-second long exposures with the hopes of catching the inhilation of a sand-grain sized particles cast off of periodic Comet Swift-Tuttle.

Got it.
  This year's shower is hampered by the recently full moon whose illumination decreases contrast between the meteors and the background sky. When the above photo was taken the Moon was 3.5 days past full shining at -11 magnitude with an 87% lit disk.   The photo below shows the moonlight encroaching from the right side of the frame.
Full frame of above photo
    Meteors weren't the only things zipping by.  Also in the sky were........

Jet  with its flashing beacon


Andromeda Galaxy encircled
   Late in the observing session my camera caught a second Perseid in the same field of view as the 2 million lightyear distant Andromeda Galaxy,

Wednesday, March 22, 2017

Venus Update 3/22/2017

   This morning Venus rose 33 minutes before the Sun and I was able to get some photos of its 1.4% illuminated crescent 3 degrees above the horizon. The separation between it and the Sun is now down to 9.7 degrees.

   In the enlarged image inset in this photograph I think that I can see the whole planetary disk not just the sunlit part.

Tuesday, March 21, 2017

Evening Star in the Morning

  As seen from our home planet, Venus never strays more than 45 degrees from the Sun.  Because of this fact it either is referred to as the Evening Star when it sets after the Sun or Morning Star if it rises before the Sun.  Today is one of the few days every eight years when it is both.

  Since last summer Venus has been hanging out in the western sky at dusk.  By Saturday it will pull even with Earth in the race around the Sun then become a prominent beacon in the dawn sky this spring and summer.  As a result of the plane of its orbit being inclined with respect to Earth's orbit, Venus will not align with the Sun but rather pass nearly 9 degree north of it as seen from where we stand.   That nine degree difference will for a few days allow the planet to precede the Sun in the morning while lingering in the western sky after sunset.

   Today our sister planet rose at 7:17 AM (30 minutes before the Sun) and will set at 8:44 PM (44 minutes after the Sun).  I was able (with the aid of binoculars) to find Venus just 9 minutes after it rose when its 1.6% illuminated crescent was just 1.3 degrees above the horizon.  I took the following photo about 5 minutes later when it was 2.1 degrees high.
  This evening I'll try to get a shot of it after sunset.  Stay tuned. Update - got clouded out for evening observation attempt. Will try again tomorrow.

  Here are a couple of not-to-scale diagrams illustrating how the planet can be observed both before sunrise and after sunset.

What ISS it? 3/4/2017

   At first (through maybe ten) glance(s) the above photo appears to be an empty or extremely underexposed black field.  It is neither.
   Here is the technical data of the image....
                                                Time/Date.........0643 AM/March 4, 2017.
                                                Exposure..........1/1250 sec @ f/16 at ISO 2500
                                                Focal Length ..700mm (500mm x 1.4x teleconverter)
                                                Camera.............Canon 5d Mark IV

  This version of the photo highlights the location of the subject.

   A closer crop reveals there actually is something in the photo. But what? A planet?

    No.  A tighter crop shows the subject has an irregular shape to it.
   A plane?
  Nope, it's the International Space Station.  The 356' wide object was 264 miles from my driveway when I took the handheld photo.  I'm somewhat pleased with the result that I was able to attain with  my manually-focused lens at an effective 700mm focal length (500mm lens with a 1.4x teleconverter).

   Things closer to my house than the ISS was when I took this photo....
                           Wrigley Field Chicago, IL.............153 miles
                           Ford Field Detroit, MI...................204 miles
                           Fort Wayne, IN..............................209 miles
                           Crane Creek SP, OH......................231 miles
                           Dubuque, IA..................................236 miles
                           Point Pelee NP Ontario.................243 miles
                           Copper Harbor, MI........................251 miles
                           Winona, MN..................................260 miles