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...

First Speckle Data is Confusing

I took my first speckle data last night (03 Apr 2021).  I got data on Sirius (looking for Sirius B) and Rigel (also a close binary).  While collecting the data and watching the screen, I saw something strange but I pressed on and collected it all.

When I was done I immediately started looking at the data closely.  What I saw was this typical 33 millisecond 'color' (using my ZWO-ASI385MC) image:

Let me explain this image a little more....

This is a very short exposure -- 33 milliseconds -- of Sirius.  An exposure of that length effectively 'freezes' the atmosphere and we see for this instant the extent and other qualities of the distortion.  Above the atmosphere, Sirius would be on a single pixel.  Instead, we get this complicated blob.  This distortion is very dynamic and causes what astronomers call 'seeing'.  There are two different kinds of distortions.  The first effects the amplitude of the wavefront, the second effects the phase of the wavefront.  Amplitude modulation caused by atmospheric distortion is called 'scintillation', oftentimes called 'Twinkling'.  Phase modulation causes 'seeing' and the complex structure you see in this image.  As the wavefront moves through the atmosphere, differences in refractive index of the air (caused by temperature differences, humidity, other aerosols, wind speed and direction, etc.) causes the wavefront to distort and become out of phase.  This has the effect of distorting the image spacially in the very complex pattern you see.  The airy rings (partial, in this case) are caused by the telescope optics -- you can hopefully see these rings surrounding a central round blob.  That round blob is the diffraction-limited image of Sirius as if there weren't any atmosphere.  Speckle Interferometry takes advantage of this and attempts to reconstruct a high-resolution long exposure image (I have 3000 images, at 30 fps that's 100 seconds).  In this case I'm hoping to see the white dwarf Sirius B.

A very important part of speckle interferometry is to do the observations using a narrow-band filter.  I just so happen to have a Hydrogen-Beta filter that's pretty narrow band (25 nanometers, 250 Angstroms).  It's a wonderful blue and, in fact, my favorite color.  The 'color' image above doesn't do it justice.

So here's the problem I have with this image: why am I seeing 'blue' parts and 'white' parts?????

Here's another image:

I'm completely baffled by this.  The only 'color' I should see is BLUE, since that's the only wavelength I'm (supposedly) letting through with the H-Beta filter.  The white pixels (which means there's red, green, and blue light getting through!!) shouldn't be there -- or at least I don't think so! (please see update 2021.04.06 below)

Assuming that it's correct, what would cause this?

Assuming that it's NOT correct, what would make it happen?

So what to do?  I thought about putting my eyeball on it with the hope of seeing something I'm not seeing with the camera.  If I don't see it with my eyeball, then I know it's a camera feature and I can focus on that.  But if I DO see the same blue/white thing, then what????  Well, the problem isn't in the camera, then.  Before the sensor is the filter.  Then the barlow, then the diagonal, then the secondary, then the primary, then the corrector plate.

Could the filter be doing this?  Maybe.  A filter could leak light at an offset?  Some kind of optical flaw?

The barlow is super simple -- nothing there.

The rest of the optical path is fine, as far as I can tell visually.

So what is going on???

I guess if I put an eyeball on it with and without the filter, I can eliminate that.  I could also eliminate the diagonal, but I'd have to refocus.  So that's what I'll do tonight (4 Apr 2021).

I'd appreciate any thoughts anyone has....

Update: clouds tonight.  Maybe tomorrow???

Update 2021.04:06

I'm pretty sure what I'm seeing in these images are two difference speckle patterns: blue and white.  Notice how there are more blobs in the blue than in the white?  That's exactly what I'd expect using a narrow-band filter versus a wide-band filter.  A wide-band filter would also produce the white light.  What I still don't understand is the relative offset -- why is blue on the left and white on the right?  I'm still baffled about how this could happen.

Projects

Keeping updated on projects.  Three categories: projects I'm currently working on, projects that I've started but are currently halted (for whatever reasons), and future projects piling up.

Current: lego sorting, bird flock flight tracking, meteor echoes

Background/halted: TESS steady stars, photometry (eclipsing binaries, asteroids, planetary moons), qNMR, TNO detection using stellar occultations

Future: speckle interferometry, asteroid occultations, meteor detection/tracking, satellite detection/tracking, twilight colors, radio telescope

There might be other inactive projects, but this is what I can think of....

Some details:

Lego Sorting: this is an active project which I'm documenting elsewhere (see this link).  This project would generally make life for most Lego people much more enjoyable, and has huge commercial potential.

Bird flight tracking: at this point, this is more of just an interest to me than anything else.  I enjoy watching large flocks of cranes spend their winters in my area as they fly overhead in their interesting and complex formations.  I've written software to take video frame input, and detect and track the paths of birds (of any kind: cranes, swallows, pigeons, etc.) as they move across the sky.  I'm especially curious to see how they move in relation to one another.  Would some kind of biologist be interested in any of this?

Meteor echoes: I've written software that can take the audio from livemeteors.com and detect meteor echo events.  The software can then make several measurements, including begin and end time, event duration, intervals between events, and peak and total amplitudes.  I've written a draft report on what I've done sofar (available upon request).  The only thing I'd like to add to this is to look at data from different times of year to see if I can detect any shower activity.  Not sure what else to do with this.  Unfortunately, it looks like this kind of observation is going away since it relies on TV stations emitting a signal on 'Channel 2' (55.24 MHz) or 'Channel 3' (61.260 MHz) -- which are going away in the next few months.  I need to look to see if there are other ways to make similar kinds of observations.

TESS steady stars: everyone is hyperventilating (understandably so!!!) about the stellar activity seen by the TESS observatory.  What's interesting to me is to find stars that show NO activity.  Once found (I've already found several candidates from Sector 1), I'd like to understand WHY they're so steady (at least on the TESS timeframe).

Photometry: I started doing very well collecting data and making measurements, but if one of my goals is to publish this data to AAVSO, then it must be calibrated to one of the standard photometric standards (like UBVRI).  At the moment, all I have is R, G, and B filters.  There is a way to calculate the transformation functions between these two, but it looks like that produces uncertainties that make the measurements almost useless (at least at the moment).  The way forward is to either acquire a set of UBV(RI) filters, and restart the photometric journey with these, OR use what I have and see if I can improve the accuracy & precision of the transformations.  Regardless, in order to do accurate photometric measurements, I need to observe 'standard stars'.  These are stars of known brightness and color (even though they might be variable -- see TESS above) that I can use to get 0th, 1st, and 2nd order extinction coefficients.  It's all explained in an excellent book 'Astronomical Techniques' by Hiltner (see chapter 8).  At this point I need to choose a direction and go with it.  Once that's done, then wow there's a LOT of things that can be done, some of which I mentioned in my brief above.

qNMR: This is quantitative Nuclear Magnetic Resonance Spectroscopy.  It's an analytical technique to tell me what compounds are in a prepared sample and how much of each compound there is.  Current testing labs primarily use High Pressure Liquid Chromatography (HPLC) and a combination of Gas Chromatography (GC) and Mass Spectroscopy (MS).  These methods are expensive and slow and are virtually blind to the contents of the sample.  qNMR will revolutionize how chemical analysis is done -- especially samples that are complex (food, soil, plants, etc.).  Huge commercial potential.

TNO detection: I've got software that takes orbital information of any object (TNOs or otherwise) from the JPL Horizons website and calculates position (RA and DEC), distance (AU), apparent size (micro-arcsec), apparent velocity (mas per second), time it takes to move one object diameter (depends on apparent size and apparent velocity), and maybe other things too.  The first goal is to get back to where I was a couple of years ago and come up with an occultation rate given a certain number of TNOs and stars.  The ultimate goal is to find an indirect way (alternative to direct imaging which for most of these objects will be impossible since they're so small and therefore so faint) of detecting TNOs.

Radio Telescope / Interferometer: I'd like to build a radio telescope and do the same kinds of things I'm doing in the optical -- photometry, etc.  Start simple and go from there.  My property is about 660 ft on each side (it's an almost perfect square of 10 acres), so I have a diagonal of about 900 feet (about 275 meters).  Radio Jove is set up for 20.1 Mhz, which has a wavelength of 14.915 meters.  Therefore, the resolution of this interferometer would be 1.22 lambda / D = (1.22 * 14.915) / 275 = 0.06616 radians, or 3.79 degrees.  Not great resolution, but probably something can be done.  I know very little about radio astronomy when it comes to hardware and data, so in order to get this project going I'll need to do a lot of homework first.  First step might be to do a Radio Jove kind of project just to get my feet wet.

I recently acquired a ZWO-ASI385MC from a very generous friend.  This will allow the following four projects to move forward.  I'll need to acquire a dedicated Win10 machine to run this.

Speckle Interferometry: this is mainly just to do it.  For those of you that don't know, SI is a post-processing technique to sharpen astronomical images.  I did this as a student 30 years ago and hardly understood what I was doing.  My understanding and knowledge has grown a little since then, and I think I can at least get to a level where I'm satisfied with the results.  But due to the small aperture sizes, I'll be limited to pretty bright targets (I might be able to get to 5th magnitude with the video-rate exposure times I need to 'freeze' the atmosphere).  Small aperture also means only a few speckles.  With an 8" primary and normal seeing, I'd expect to see about 10 speckles on average.  Targets will include binary stars, Jupiter (using it's moons as point sources), and that's about it.  Not sure what else to do with this.

Asteroid occultations: these don't require as short exposures as speckle does.  I'll need to test this, but I'm guessing that a 0.1 second exposure will get me down to about 8th mag.  That's still pretty limiting since there aren't many 8th mag stars or brighter that get occulted.  I'd like to observe occultations of stars by trans-Neptunian objects (TNOs) since those occultations are usually a pretty long (10's of seconds, or minutes) so I could increase the exposure time to see fainter stars (which means more occultation opportunities).  The most important thing about asteroid occultations is the timing.

Meteor and Satellite detection and tracking: the ZWO camera comes with a fish-eye lens that appears to have a pretty wide field of view.  This means it has the potential of being used as an all-sky camera.  This opens up the possibility of satellite and meteor observations, but also non-astronomical observations like clouds, birds, and other transient events.  This could also be used in the twilight project.  Meteors could be measured (brightness profile, color, location in the sky, motion, etc.).  Satellites observed can have their positions measured and compared to calculated orbital data.  Orbit changes or unknown satellites could be observed.

There are other projects I've worked on the past and would like to get back on them, or projects I'd like to try:

• Using IRIS data to map the south atlantic anomoly
• Twilight observations: this is a project I did for someone several years ago, but was stopped because the effect they were expecting / looking for didn't appear.  However, how the sky color changes at various stages of twilights caught my interest and I'd like to get back on that to see where it leads me.  The ZWO camera can be used for this, too.
• Obtain occultation timing spacially not temporaly