A look at M99

I intended to get a good hour in for LRGB on this, but as it turned out the guiding was intermittent and I really only got 4 each good RGB frames for 20 minute total exposure.  So the image is not deep.

M99

M99, exposed 4-13-2013; RGB each 4 x 300 seconds. 12″ LX-200 at f/10 with SBIG ST-10XME, resolution .47 arc-seconds/pixel. Click image for larger size.

I’ve started using CCDStack and, when calibrating the frames, was getting a “negative ADU” alert when applying the flats.  This was quite mystifying.  It turns out I was not making flats with enough exposure. I resolved it by re-exposing the flats with the 40 watt bulb (instead of 15 watts), increasing the exposure so I was getting about 60% full well capacity.  That satisfied CCDStack, and should make a better flat. I’m still seeing irregularities in the background areas, which were repaired in Photoshop with Astronomy Tools from ProDigital Software.

M99 is a “grand design” spiral, except for its crazy arm which has presumably been distorted by a close encounter.  Because it presents itself so well, it’s been the subject of a lot of research, mainly concerned with the distortion of the spiral. This gets interesting because HI (neutral hydrogen) mapping from Areceibo showed a massive (about 100 million solar masses) rotating accumulation of neutral hydrogen fairly nearby, dubbed VirgoHI21.

Wikisky screenshot of M99 vicinity

Wikisky screenshot of M99 vicinity

There’s nothing to see of Virgo HI21, it seems to be mass without stars, which only shows up in radio survey.  From its mass, it should be a 12th mag galaxy.  The discovery of VirgoHI21 was greeted with great excitement, because it was thought to be the first candidate for a dark matter galaxy, which maybe it is.  Would that be cool!  But it seems that dark matter refuses to reveal itself that easily. Evidence is mounting that the VirgoHI21 is a tidal tail, probably from M99, the result of nearby NGC 4262 gliding thru the neighborhood 280 million years ago. This is all gleaned from the detail page on M99 from WikiSky.

NGC 4298 and 4302 are a lovely pair that I will image soon, if it ever clears up.

Orion and New Moon

We’ve had a rainy week and 5 or 6 inches of rain, but it cleared up nicely.  I planned a run on M99, which I had botched a few weeks before.  i unparked the scope, fired up the camera & coolers, opened the roof and aimed at Denebola to check the aim.  That accomplished, I headed inside to do the rest from the living room.

I stepped out of the Hut into a lovely twilight and had to just stop to take in the Big Picture, which is so often lost when futzing with gear.

The Hut in a lovely twilight. Canon 60Da, 38mm; 4 seconds and 1/60 sec exposures combined in Photoshop.  Our local ugly green gradient was cheerfully removed with the Astronomy Tools Soft Gradient removal action.

The Hut in a lovely twilight with Orion and our moon. Canon 60Da, 38mm; 4 seconds and 1/60 sec exposures combined in Photoshop. Our local ugly green gradient was cheerfully removed with the Astronomy Tools Soft Gradient removal action. The red wash was added by my headlamp. Click image for full size.

I heard peepers chorusing across the field and the  redwings calling in the bamboo patch. Then coyotes had a brief earnest discussion.  I haven’t processed the M99 frames yet.  Will put them up soon.

Supernova 2013am in Leo

In my continuing, ongoing shakedown, I set up a full LRGB series of M65 (NGC 3623) on the clear, moonless night of April 3. The forecast was good, so I set things running and went to bed. Somewhere in the green series, things murked up a bit, and the tracking crapped out for some of the greens and all of the blue.

M65 on April 3, 2013. 10-5 minute luminance exposures with LX200 12" at f/10 with ST10XME.

M65 on April 3, 2013. 10-5 minute luminance exposures with LX200 12″ at f/10 with ST10XME.

The luminance looked pretty good, except for the usual annoying, slightly oval star images.  But wow, quite by accident, the image shows Supernova 2013am, discovered on

Supernove 2013am

Supernova 2013am, UT 03:50 April 4. .47 arc-seconds/pixel

March 30 by M. Sugano (Japan).  I’m probably the only one who didn’t know this was now playing in one of Leo’s Kodak Photo Spots.  Still, hitting it by accident means I could have discovered it!  Well, if I had actually noticed it!  I found out about the supernova via a casual mention on a mailing list, and thought, “didn’t I just image that?”

Control System Prefs with AppleScript

I use TeamViewer to control the PC in the Hut, because it’s free, and it often works quite well.  The thing that drives me most nuts about it is how to right-click remotely.  I’m working from a Mac Book Pro with a trackpad.  I suppose I could actually use a two button mouse, but I haven’t used a mouse with a MBP forever.  I’m not even sure I have a two-button mouse… The solution is to go to the System Prefs Trackpad panel and set the Secondary Click checkbox for two-finger click.  trackpad-panel

That actually works great for TeamViewer remote sessions.  But it drives me nuts in MacLand, because I seem to use two hands on the trackpad and am constantly getting unwanted context menus.  So I wanted a handy way to turn on or off the two finger click trick programatically, which is to say, with AppleScript.

So how do you get your hooks into the Systems Preferences elements?

The key is to use System Events to get and set the window’s UI elements.  Here’s a simple script that collects the UI elements for the frontmost window of the application you want to peek at, in this case System Preferences:

tell application "System Preferences"
    --bring System Prefs to front
    activate
end tell

tell application "System Events"
    tell process "System Preferences"
        set windowsProperties to entire contents of front window
    end tell
end tell

return windowsProperties

The results window displays a lengthy list of elements that you’ll have to noodle over to figure out what you want.  In this case, I had opened System Preferences and clicked  to open the Trackpad panel, as in the image at top.  Here’s what the ScriptDebugger window looked like:  results of ui inspector

 

Here’s the pasted value (pasted into ScriptDebugger) from the results for “checkbox 2 of tab group 1 of window “Trackpad” of application process “System Preferences”:

tell application "System Events.app"
    tell application process "System Preferences"
        tell window "Trackpad"
            tell tab group 1
                tell checkbox 2
                    -- your code goes here
                end tell
            end tell
        end tell
    end tell
end tell

This nested tell set is clunky, but lets you easily understand exactly what’s going on, and you can just paste it into a script to get or set a value to a particular UI element.  I had to horse around to check or un-check the  secondary click checkbox.  “Normal” checkboxes have a value of “0” for unchecked and “1” for checked.  The script would let me get the value, “0” or “1”, but not let me set the value.  However, it did let me treat the checkbox like a button, and “click” it.  Go figure. That would be a problem if I really needed to set a particular value, but in this case, I’m happy to let it toggle:

--toggles "2 finger click" for secondary click on or off via trackpad pane of system Prefs
--needs "does trackpad panel exist?" 
--JJ McClintock 20130411

tell application "System Preferences"
    activate
end tell
tell application "System Events"
    tell application process "System Preferences"
        tell window "System Preferences"
            tell scroll area 1
                --hopefully this will catch issues if no trackpad panel exists
                try
                    click button "Trackpad"
                    tell application "System Events"
                        tell application process "System Preferences"
                            tell window "Trackpad"
                                tell tab group 1
                                    ----set value doesn't seem to work
                                    --set value of checkbox 2 to 1
                                    ----get works fine
                                    --get value of checkbox 2
                                    --click works as toggle
                                    click checkbox 2
                                end tell
                            end tell
                        end tell
                    end tell
                end try
            end tell
        end tell
    end tell
end tell
--we want to quit System Prefs when we're done
tell application "System Preferences"
    quit
end tell

I saved the “toggle 2 finger secondary click” script as an application bundle and placed it in my script menu folder. Now I can turn on 2 finger click when I begin a TeamViewer session and turn it off the same way when I’m done.