More Comet Musings

The latest obsession has been trying to photograph comet NEOWISE, specifically, its tail.  I am coming to the conclusion that

• the comet was better positioned last weekend at 4 AM than it has been the last couple of evenings at 10 PM;
• there's a lot of light pollution to the Northwest of us;
• having a camera that didn't need to be jury-rigged to the tripod would help, and;
• that my camera has a built-in interlock that is preventing exposures greater than 1 second and 1600 ISO (or a half-second at 3200 ISO).  

Right now, the comet is too close to the horizon for it to be visible from our backyard.  It took me a while to figure that out.  In about a week and a half it should be closer to the Big Dipper and I won't have to travel six blocks west to the other side of the hill to see it.

NEOWISE, at least from the middle of Eugene, is difficult to see in the post sunset glare.  Until I remembered that my mobile has a built-in compass, I was guessing at the direction the comet is in and how far up in the sky it would be.  For the record, at 10 PM Thursday night, the comet is at a heading of about 328 degrees (or a little over 30 degrees West of North); if you draw a line from the bottom of the Big Dipper (as if it were pouring water) until you hit the 328 degree mark, you'll be (more or less) looking at the comet (about 10 degrees up from the horizon).  Add (roughly) 15 compass degrees for each hour after 10 PM (so, presumably, and I haven't tested this, NEOWISE would be due North at midnight in the Eugene sky).

I don't know if it's just standing around at twilight with a camera and a tripod, or my longish grey hair, or my glasses or what, but my experience so far hunting NEOWISE has included strangers walking up to me (unmasked), or stopping their cars and shouting from the driver's seat, to ask if I can see the comet.  Usually about three per night.  The unmasked folks are mostly keeping social distance.   I think everyone's been seeing really cool photos of a comet with a long tail... which is sort of true, but the pictures either have been processed or it was an extra long exposure (with some kind of tracking to keep things steady).

I'm looking forward trying to photograph NEOWISE some place with less light pollution -- and maybe some shots with the star-trails option on.  I'm hoping this will allow me to get a clearer photo (or more) of the tail.

Saturday, 4:20 AM

Sunday, 4:20 AM

Tuesday, July 14, 19:15

Thursday, July 16, 10:00 PM









Thursday, July 16, 10:00 PM

Early Mornings with Comet NEOWISE

 I haven't felt like writing lately, and as a result the blog has gotten quiet.  Some of my writing impulse has gone to Facebook, Twitter, and Instagram -- which is, I suppose, a reflection on my ability to be able to hold more than a handful of thoughts together for any length of time.  I think this is the point where I say something about Mercury going direct and communications opening back up.

On the astro-photography front, I have managed to jury-rig together some zip ties to keep my camera (mostly) on my tripod.  Without the mounting hole in the camera's body, I'm not able to really secure the camera to the tripod, and the zip tie trick is temporary at best.  It worked for some photos that I took of comet NEOWISE over the weekend, but I was anxious that the camera would slip off of the tripod and fall to the ground.

Comet NEOWISE has been visible in the northeastern skies over Eugene, from about 3:40 AM until 4:50 AM, when the Rosy Fingered Dawn makes the sky too light to discern the smudge of the comet and its tails.  Or, at least it has when the sky hasn't been clouded over.  It's below the constellation of a Auriga, which had been off of my radar until last week (although I was vaguely aware of one of its stars, Capella).  Looking at a star chart, I should have at least known that it connects to one of the horns of Taurus.

The cats work me up in time to see NEOWISE  Wednesday, but I wasn't able to pull myself out of bed.  I tried to see it Thursday, but misjudged how light it would be by the time I eventually strolled outside.  The photos I snapped of Venus convinced me that I had to use some sort of stand to hold the camera ready.  Friday it clouded over.  Saturday morning, though, I managed to get out and look for it.  I searched and searched, easily spotted Venus and Aldebaran, but was mystified as to where Capella was, much less NEOWISE.  I figured it was below the tree-line across the street and strode up the hill a bit and managed to sight it.

It's always odd to be photographing the sky in the dark at the side of the street, let alone in an intersection, which was where I was.  I jacked up the camera's ISO up to 1600 to reduce shutter speed.  I hand't figured out the zip tie trick, so I was holding the camera and the tripod mount together with my hand and attempting to zoom and hold things steady as I pressed the shutter button.  And hoping that a car wouldn't come down the street.  After a few shots, I paused to enjoy the comet with my eyes and not through a camera LCD.  Then I went and woke Mark before going back out.

I had taken some more photos from the intersection when Mark came out with Aoife and said that the comet was visible from our backyard (both safer and more shielded from streetlights and porch-lights).   In the backyard, there were more useful references to orient with, including the brick circle.  I took more photos in the brightening sky, then turned the camera to Venus and Aldebaran and the Moon and Mars.

Sunday morning, I got up a little more early, but there was a a skrim of haze over the northeastern sky.  I dozed and intermittently checked the skies until they cleared.  This time, I had the camera's shutter remote (not touching the camera means it's more steady).  I had thought that if I dialed back the ISO to 400, I could have a longer exposure time (3 seconds).  I think a combination of subtle tripod slide, the haze, my inept focusing, and the increased exposure time wound up with, well, I suppose I could say the photos that came out looked like van Gogh's "Starry Night."...

I experimented with turning the ISO up to 3200, thinking that I would be able to increase the shutter speed.  However, there's an interlock that moves the limit on the timer.  What I learned was that while theoretically a half second exposure at 3200 ISO is equivalent to a second exposure at 1600, the shorter exposure picture comes out bluer and whiter than the longer one.  The other lesson is that camera takes sharper images at slightly less full zoom than at full zoom, and that fine-tuning the focus on a star and then not changing the zoom really is a must.

I'm looking forward to later in July when NEOWISE becomes an evening sky object and hangs out underneath the big dipper.  For one thing, I won't feel so indolent for the rest of the day after getting up so early.  I'm also hopeful that as the comet gets nearer to Earth, it will become larger and brighter.  I think the last comet I saw (sort of) was comet Hale-Bopp, back in 1997 (although I remember the local flooding more than the comet).  Looking through historical records, Oregon must have been clouded over in January 2007, because I don't remember seeing that comet, either.