All Sky Camera Solar Eclipse

LOCAMS eclipsing the sun:

Strange Lights In Last Night's Sky

I can't account for this image sequence take with one of my cameras (USL010) last night (2021.12.23 UTC).  Time goes from left to right, top to bottom:

Literally looks like some kind of directed beam.  The video show it pretty well.  Timestamp about 00:11

Click here for video

Any ideas???

For context, here's a full FOV (89 x 47 degrees):

b Per Update

It's been cloudy and a bright moon these past several days.  Now it's past full moon and there's a little bit of dark now in the early evening.  Tonight's data looks promising sofar:

b Per is marked with the arrow.  Image taken at 04:48:06 UTC.  Nice S/N.

Headline: Astronomer Admits He Likes Clouds

I see this all-sky camera system eventually operating in four modes:

1. Daytime, Clear

2. Daytime, Cloudy

3. Nighttime, Clear

4. Nighttime, Cloudy

Much can be done with each of these...

Here's a Daytime, Cloudy image:

Algol Eclipse

Forgot to mention that I observed and measured a recent eclipse event of Algol on 5 Dec 2021 using cameras from my all sky system.

The results are very promising.

This first plot shows the brightness of Algol (black dots) and the brightness of a nearby reference star (red dots):

I can then use differental photometry to calculate a magnitude difference, and I get this:

The magnitude difference is just:

M2 - M1 = -2.5 log10 (I1 / I2)

where the M's are the magnitudes and the I's are the measured intensities.

I was able to just catch mid-eclipse, and it looks like the maximum difference is about 1.3 magnitudes, plus or minus about 0.1 magnitudes.  Looking up the actual numbers, I see that the difference is 1.27 magnitudes!  My conclusion is that I'm able to make accurate measurements with a decent amount of precision.

b Per Obs Campaign Begins

From now until 30 December, I'll be measuring the brightness of b Per.  This system is expected to go into eclipse sometime around 22 December, but no one knows for sure.  It's a complex system.

Here's the alert from AAVSO.

I'm looking at the images from last night (16 December 2021 UTC) and yes indeed I'm seeing it just fine.  I'll be able to grab this data no problem.  Whether the data is useful?  Time will tell.

Here's one image from about 04:00 UTC (target b Per indicated with an arrow):

... and one from 05:00 UTC:

.. and at 06:00 UTC:

I'll start grabbing all this data pretty soon...  I should have this on multiple cameras.  I'll grab all the vids and see what's what....

Those nearby stars are only a couple degrees away so I'll be able to pretty confidently do differential photometry and cheat a lot of the calibration problems associated with absolute photometry.

BTW -- here's the full image to show what I'm dealing with:

Very beautiful, but what a mess!!!!

In any case -- full steam ahead

Looks Legit!

I've been looking at the possibility of doing photometric measurements of stars and other targets in these all-sky camera images.  Since magnitudes are being computed for the meteors and the stars detected in each FOV, I can only assume that I can get pretty nice calibrated photometry.

I was all ready to start diving into the RMS code to find the info I need to do the translations between pixel values and magnitudes, when it dawned on me that if I did differential photometry, I wouldn't have to worry about any of the problems associated with trying to get an actual magnitude.  I'm fine with magnitude differences.

As a reminder, the difference in astronomical magnitude is defined as:

M2 - M1 = -2.5 log10 (I2 / I1)

I can measure I1 and I2, which are the sky subtracted sum of pixel values centered on the reference or target.

Here's the I1 and I2 values as a function of time for the reference (rho Per, red dots) and target (Algol, beta Per, black dots):

... and when I compute the differences in magnitude, I get this:

What this is telling me is that over this time period (which as you can see lasted from about the beginning of the eclipse to just barely past the mid-point), the difference in magnitude goes from about 0.25 to 1.3 (+/- 0.1).

The actual difference at mid-eclipse IS 1.3 magnitudes!!!! (https://en.wikipedia.org/wiki/Algol).

I also measured the precision of the reference star.  There were 1200 total data points.  Of those, a few were obvious problems.  In the end, I used 1163 data points (96.9% of the data), and got a precision of about 10%.  I can tighten up on the data points selection a little but (eliminating outliers), and actually get down to about a 6% spread.  That's acceptable for the data I have!

This is all very encouraging.  I'd like to get a full eclipse.  The next one that'll be visible from my side of the planet is on 21/22 December (UTC):

start: 22 Dec 2021 07:52 (00:52)   mid: 22 Dec 2021 12:41 (05:41) end: 22 Dec 2021 17:30 (10:30)

and then a better one on 27/28 December (UTC) that'll be going on all night:

start: 28 Dec 2021 01:30 (18:30)    mid: 28 Dec 2021 06:19 (23:19)    end: 28 Dec 2021 11:08 (04:08)

Good times!

More Geminids 2021

 



and this is it for now... 742 detected meteors in this image:

I've also been playing around a little with putting some false-color on these to see how they look.  Here's some examples:

Geminids December 2021

This is a long exposure of the entire evening of 11/12 December 2021 from all six cameras.  It's definitely Geminid season!!!

Typical View

 

Sky, moon, stars, reflections, satellites....

Been Too Long

 

I've been using my discord server as a blog, and that needs to end.  THIS is the place to talk about my astro work.

About a month and a half ago I acquired a LOCAMS system in collaboration with Lowell Observatory.  This is an all-sky camera system using six cameras and six raspberry pi's to detect and measure meteor events.

This system is also part of the Global Meteor Network, which contains some 500 stations (and growing) worldwide.

Each camera in my system has it's own designation:

USL00X

USL00Y

USL00Z

USL010

USL011

USL012

The field of view of these cameras is about 90 degrees by 45 degrees -- so a fairly nice chunk of sky.  Each camera points to a different part of the sky, with a little bit of overlap.  I've yet to make a full mosaic, but it's on my list.

The cameras are running at about 25 frames per second.  The software grabs 256 frames at a time but after that I haven't gotten into the software enough to know what exactly it's doing.  I'll describe more of the details as I learn them.

My station will detect several hundred meteors every night, but only a few of them are seen by another station.  This makes for a legitimate detection since not only did an independent station see the event, but the software can now combine the data from each station and triangulate in order to get a 3D position of the meteor trail.

In the end, various detection event reports are created.  One of them is a table with the beginning and ending latitude, longitude, and altitude.  I can take this data and compute line-of-sight distance and meteor trail length for each event.  I can then make a plot of each showing the distribution of distances and lengths:

These histograms shows detection from the first 8 nights of Dec 2021.

Notice that one meteor trail was 100km long!  Here's a picture of it from USL010 on 4 Dec 2021:

Just really quick there was a nice fireball going right by Sirius on the 4th.  Left a trail for >5 min afterwards.  Here are some pics:

more as time allows...