Starting Soon

I should also mention that this observing program begins on Monday, 20 April 2020.  That's pretty much the first day that Jupiter and Saturn are sufficiently high in the sky (about 20 degrees elevation and rising) to get some decent data.  Saturn will still be a little low at first, but it's right there so why not?

I also made a list of eclipse events for HW Vir, which is currently my favorite EB system.  Here they are for the next week or so that I'll be able to see between 10h and 11h UTC:

S 20 Apr 2020 10:52
P 21 Apr 2020 10:41
S 22 Apr 2020 10:29
P 23 Apr 2020 10:18
S 24 Apr 2020 10:07
S 27 Apr 2020 10:57

where 'P' and 'S' are Primary eclipse and Secondary eclipse.

I'm observing between 10 and 11h UTC because that's when Saturn and Jupiter are up.  Iapetus will be in a perfect location (almost as far away from Saturn as it can be):


The reason I need Iapetus to be far away from Saturn is that 1 or 2 second exposures are required for this target.  It's a faint visual magnitude 12.  Doing that long of an exposure with Saturn in the FOV probably wouldn't hurt the CCD, but wow it would be incredibly overexposed.  So all of this data will not include Saturn, but will hopefully contain a bright reference star most of the time.  Iapetus is sufficiently far away from Saturn during most of its orbit to make this project possible.

If I get other moons in the FOV, that'll be bonus.

Research Direction(s)

Iapetus: photometric light curve (brightness versus orbital phase, brightness versus time)

Galilean moons: photometric light curves (brightness versus orbital phase, brightness versus time)

Eclipsling binary star systems: topic TBD

For the moon photometry, the idea is to keep the data collection short and sweet.  There's no particular reason to sit on the targets more than about 10 minutes.  That'll allow me enough time to get a decent statistical sample while all the moons are at a single orbital phase.  So observing Saturn and Jupiter will literally take about 30 minutes plus setup time.

Along with that, I'll collect photometric data on a selection of eclipsing binary stars.  I just got the ebook: "Eclipsing Binary Stars: Modeling and Analysis" by Josef Kallrath and Eugene F. Milone.  It seems comprehensive enough to be able to give me a pretty decent idea about what direction I want to take and what data will have to be acquired either by myself or from various surveys.

The computer saga: Let me tell you a computer story.  About two years ago I bought a fairly new computer to replace one I've had for a while that I've been using as my 'research computer'.  This is where I have all of my working data, along with all my software to do the data reduction and analysis.  The new computer arrived and within the first week the ethernet adapter (on the motherboard) got zapped by a lightening strike.  So there was no way to have a wired ethernet connection.  Ok, so I switch to wifi with a little USB ethernet dongle.  I got the computer set up and configured, and installed all the python stuff so I could start my switch from IRAF to the various astronomical python packages that are now available.

One day the system asked if I wanted to upgrade the OS.  I figured this was a good time to do that, so I went ahead with that.  After the upgrade, no matter what I did I couldn't get the wifi to work!  So now I have a pretty decent machine but no reasonable way to get data in and out of it!

I found another computer that had windows 7 on it.  I decided to replace the hard drive with the one from my new computer.  This went well for a couple days until THIS computer decided that it didn't want to power up anymore.  It just sat there and clicked!

Needless to say, I was pretty bummed out.  So I put all these computers away and sort of forgot about them.  Thinking about this new research and still wanting a newer computer to do the work, I started thinking about either getting yet another new computer, or figuring out how to cobble together something with the pieces I have.

I also had acquired a new wifi USB dongle.

This past weekend I pulled everything out.  I put the original new machine back together (less one memory stick which I can't find, so I only have 2 GB of memory at the moment), plugged in the new wifi adapter and VOILA the machine came up and connected to my wifi!  So yay now I have a working machine with some decent processing power.  I'd like to get at least 8 GB of memory on this machine.

Obs-Session Data

Here's some stuff from recent obs-sessions.

First, here's a light curve from the eclipsing binary star HW Viriginis:

The position of HW Vir in the sky seems to be a place where a lot of satellites move.  Here's an example of a single 3s image:

Here's a combined RGB image of open cluster Messier 46, with planetary nebula 2348 in the background.  The color information of the stars and nebula will hopefully tell me a little bit about their situation:

A long exposure (about 450, 3 second images) of the Eskimo Nebula (planetary nebula, NGC 2392):

Here's the same image as above, but stretched to show the faintest stars:

Here's a long exposure (about 450, 3 second images) of the Globular Cluster Messier 5:

Here's a video showing the motion of asteroid (6) Hebe:

... and asteroid (433) Eros:

Observing asteroid (6) Hebe

From about 03:30 - 05:30 UTC on 19 April 2019, I collected some reflected photons from the main-belt asteroid (6) Hebe.

At the time of the observation, (6) Hebe is in the constellation of Gemini.  The approximate RA and DEC was: 06h 55m 24.3s +19d 38m 20s.

I took 700, 4 second exposures.  Even during the observation, I noted that I probably should have done 3 second exposures.  When I decided on 4s exposures, the tracking was looking really nice.  Maximizing the exposure time improves the signal-to-noise, so being able to do 4s exposures would be better than 3s exposures.  The problem is that the tracking quality kept changing, so much so that many of the star images were short streaks.

So because of the pretty poor tracking, my first run at stacking and making some photometric measurements on the two reference stars in the field-of-view used 544 images.  So that means I've lost 156 images, or 22.3%.  That's a bit much, so I'll need to go back into the data to see if I can modify the parameters in the code to pull out a few more images.

Here's a single image:

Here is the stack of all 544 images (inverted greyscale):

Here's a movie showing the motion of (6) Hebe:

https://youtu.be/HA3sQQUsDLU

There are some strange things in this dataset that I need to look at carefully.  More on this later...

Eclipsing Binary Star HW Virginis

On 23 March 2019, I observed the eclipsing binary star HW Virginis.  Here is a preliminary light curve of the event:



The x-axis is the Julian date, and the y-axis is the relative magnitude compared to a reference star in the same field of view.

Here's a long exposure of the field of view:

Deepest Image Sofar

This image is a stack of 954, 3 second exposures of the XZ Canis Minoris region.  I'm pretty easily seeing 17th magnitude stars, and maybe some hints of 18th.

Obs-Session 190322

Had a pretty nice obs-session last night.  I collected data on R Leo, and the asteroids (2) Pallas and (433) Eros.  My only complaint is that I had trouble finding the targets and that task took too long for every target.  With my first target - R Leo - I even came back into my office and checked the coordinates because I couldn't seem to find the star patterns on the chart.  But I'm very stubborn so I finally found it.  Collected 100, 2 second, 2x2 binned images and 40 darks of R Leo itself, and then another 100, 2 second, 2x2 binned images of a nearby comparison (or reference) star.

I then proceeded to the asteroid Eros, which was still high in the sky but getting lower by the minute.  Had trouble finding the target, but again prevailed and finally figured it out.  The main trouble was that there are sooooooo many stars!

And here's Eros moving by showing you the first image followed by the last image in a loop:

I've also made a movie of the entire session with Eros:

https://youtu.be/31JWsSTi4Jk

I then moved on to (2) Pallas.  Same trouble finding the the target, but for the opposite reason.  In this part of the sky, the stars are SPARCE!  So simply finding a pattern of stars that fit into my small field of view (12 arcmin by 9 arcmin) was a challenge.  I was about to give up for the night when I finally saw a recognizable pattern which was surprisingly close to the target!

Here's an image of (2) Pallas:

... and here's the same kind of movie as above.  Notice how much less Pallas moves versus Eros.

my manual stacking here isn't perfect, so you'll notice that the star at the lower right appears to be moving.  It's not.  (2) Pallas is that bright one at upper left.

I collected 200, 2 second, 2x2 binned images of (2) Pallas.  Wow that's a lot of two's.

So now I need to reduce the data and then make the photometric and astrometric measurements.  That's all just tedious work which I'll get done in a blast of time in the next couple of days.