Urania

The Xquartz project is a useful one for Leopard users of astronomical applications because of the dependence of most astronomical applications on X11. A few days ago (what can I say, its finals and I am swamped with exam writing and grading) they released version 2.2.1. It contains all the tweaks that made it into the previous version and also includes

• All packages updated to versions intended to ship as part of X11R7.4 (as of 2008.04.21).
• Fixed multiple crash-causing bugs in the server.
• Fixed cmd-tab to properly move all windows forward when entering X11.app.
• Cleaned up multi-monitor support (still not completely bulletproof) [I have 2 monitors, so this is a big one for me].

As I have noted before, Apple includes some of the work done in this project in OSX updates, so it is suggested that you install the latest XQuartz release after updating to 10.5.2 (and any future 10.5.x or security updates).

This was posted on my friend John Martin’s blog. He is an astronomer and an educator, like myself. As finals roll around and students realize that slacking off in the class is going to have consequences, they get… creative. Here is John’s post:

This warning should be posted under my class in the course offering directory:

WARNING The Astronomy-Physics program has determined that doing poorly in Astronomy 101 may have deleterious impact beyond your GPA. Students failing Astronomy 101 report a higher incidence of: deaths of grandparents, close relatives who discover they have cancer, chronic personal health problems, influenza outbreak, computer hardware failure, traffic accidents, complete melt down of their university email account, death of beloved pets, and inability to find adequate child-care services. A high degree of correlation has been observed, however the cause-effect relationship is still under study. Students should be advised to enroll in this course and take it lightly at their own risk.

[From Warning About Doing Poorly in Astronomy Class]

Immediately after installing SAOImage DS9 5.2, I had a major failure of the application and initially I just thought it was some sort of build bug. This is what I posted at that time:

[HOLD OFF ON THIS UPDATE! I have discovered that at least on one of my systems, this version of ds9 is refusing to run properly. It launched once, but when I attempted to check the “About SAOImage DS9”, it triggered the following error:

 “An internal error has been detected local header mismatch couldn't open “zvfsmntpt/doc/sun.gif”: no such file.

(this occurred in both Aqua and X11 versions). Furthermore, all future attempts to launch ds9 (again, either Aqua or X11) fail with the following error:

Error in startup script: couldn't read file “./zvfsmntpt/src/ds9.tcl”: no such file or directory  

Even removing the preferences file at ~/.ds9.prf didn't help.]

Apparently, my problems with SAOImage DS9 in Leopard are a known issue. If you configure the built-in Firewall to “Set access for specific services and applications” so that you can approve “holes” in your firewall on an Application by Application basis, your first launch of SAOImage DS9 will irreparably damage the application!  Unfortunately, Apple implements the application firewall in part by modifying the Application package of the Application you are running by digitally signing it if it was not digitally signed by the developer (adding a file called CodeResources to the Application package). According the Apple’s documentation on this:

If you run an unsigned application not in the Application Firewall list, you will be presented with a dialog with options to Allow or Deny connections for the application. If you choose Allow, Mac OS X 10.5 will sign the application and automatically add it to the Application Firewall list. If you choose Deny, Mac OS X 10.5 will sign the application, automatically add it to the Application Firewall list and deny the connection.

So basically,Apple doesn’t warn you in the dialog box that comes up that it has whatever decision you make, it will modify the application by digitally signing it and it doesn’t give you a way to avoid this. This is, in my opinion, is an incredibly boneheaded move on Apple’s programmer’s part. They readily admit that

  Some applications check their own integrity when they are run without using code signing.

They suggest the application firewall will try to automatically detect these and avoid modifying them, but they should give you, the user, the option instead of making the decision via some internal algorithm.  MacOS X shouldn’t assume its OK to change an application. In the case of SAOImage DS9, they are irreparably damaging the application without leaving you a way to avoid the damage once you trigger the application firewall. Shame on you Apple. The only way to fix it is to reinstall the application!

So when I figured this out (a tip of the hat to this post on IRAF.net). I reinstalled the SAOImage DS9 executables (both Aqua and X11 versions) and before launching them, I set the Firewall (via the Security Pane of the System Preferences) to “Allow all incoming connections” (this is the default mode, so it is as secure as MacOS Tiger was). Everything now appears to work just fine.

Personally, I believe an application that fails its checksum should present a message indicating that is the problem instead of just crapping out, but in this case, the fault lies mostly with Apple. Apple is damaging applications by making this critical decision in the background, without user intervention!

[See my more recent post warning about MacOS X Firewall settings and how they can destroy the SAOImage DS9 executable during its first launch! This problem is avoidable by tweaking the Firewall settings, but once you have launched SAOImage DS9 with the bad settings, the application is damaged can can't be relaunched again. A reinstallation is the only solution, so it is a good idea to avoid this problem.]

The folks in Cambridge have kept busy. They have released SAOImage DS9 version 5.2. The versions for MacOS X include the following:

• Aqua 10.4 Tiger (Universal)
• Aqua 10.5 Leopard (Universal)
• X11 10.4 Tiger (Universal)
• X11 10.5 Leopard (Universal)

The rather extensive changes are detailed in the release notes here, but the notable ones to me include:

• ANALYSIS: for MacOSX tiger, wrap cmds with shell and PATH.
• GUI: change default directory for standard dialog to $HOME.
• ANALYSIS: add /sw/bin to default path for MacOSX. While unstated in the release notes, this is clearly an attempt to support Fink, which places its installation in the /sw directory.
• GUI: ds9 will now start in the users home directory for MacOSX Aqua users when invoked from a double click and the default dialog box is Motif or Windows.
• MACOSX: fixed a problem with printing non standard colors.
• MACOSX: restore postscript printing.
• REGIONS: apply WCS to fits regions if present.
• GUI: add support for user configured button bar.
• CATALOGS: add support for simbad.
• IMEXAMINE: added support for key stroke events.
• Although unstated in their release notes, they are now apparently providing universal binaries instead of PPC and Intel binaries for MacOS X.

I have previously posted notes for integrating upgrades of DS9 into the Scisoft OS X installation and they still work just fine.

One of my favorite little programs is LaTeXit.  It allows you to typeset LaTeX equations outside of a text editor and then drag the results into programs like Keynote or Pages.  It was not fully compatible with Leopard and my fix was a kludge that could break other programs.  Pierre Chatelier has released updated LaTeXit to version 1.15.0, which restores Leopard compatibility.  Notably, you can now use the default0 /etc/profile file without fear.

During our observing run at CTIO, Dr. Roberta Humphreys lamented apparent disappearance of a pack of foxes that liked to hang around the observatory. The cooks, who had traditionally tossed out some scraps to the foxes, stopped doing it. Apparently, there was a concern that the foxes were becoming overly dependent on the hand outs. On my last morning at CTIO, I got to see one of the foxes and snapped a few pictures.

Above Photo is the fox with the Blanco 4-meter telescope in the background.

The Above Photos show the first first nibbling on something than turning around, apparently looking at the small telescopes on the Cerro Tololo summit.

Funny thing is as I was dumping the pictures from my camera, Roberta knocked on my door, and I opened it, just in time to see one of the foxes run behind Roberta in my field a view. I pointed it out to her and she was happy the foxes were not completely gone.

[This originally linked to version 2.2.0, but there was a security related bug in version 2.2.0, so this release has appeared to replace it.]

The Xquartz folks have updated Xquartz to version 2.2.0.1. Xquartz is an effort to provide a better X11 server for Leopard than Apple provides, being proactive in providing fixes Apple will likely include later. The release notes are long and cover a bunch of updates to various items, including:

• Added informational output when falling through to failsafe startup in X11.app
• Unsetenv(DISPLAY) when falling through to failsafe startup in X11.app
• Exposé now works as expected
• X11 works better with spaces

I suspect the discussion of ‘failsafe’ startups is to provide a more informational failure than what was happening before for people like myself who transitioned from previous MacOS X installations and had been manually forcing the DISPLAY variable to point to :0.0, which is somewhat standard in the Unix world.

I’d recommend grabbing this Xquartz update and applying it if you use Leopard and astronomical software. Its a double-click install. Apple does watch this project (one of the developers is Apple’s X11 developer), and as noted on the Xquartz site:

Apple included some of the work done in this project in their 10.5.2 update and will likely include further changes in possible future updates of 10.5.x. It is suggested that you install the latest XQuartz release after updating to 10.5.2 (and any future 10.5.x or security updates).

In other words, while some of these fixes will likely end up in the official MacOS released by Apple, if you want them now, use Xquartz. Furthermore, since Xquartz does over-write Apple’s default X11 install, this means that if Apple upgrades X11 in a future patch, you could end up with a broken install if you used Xquartz. Personally, I haven’t had a problem, but I suggest you keep the Xquartz package around, and re-install it after any future MacOS X updates.

Well, after a bit of a bumpy start, this observing run has gone reasonably well. We think we will be able to get the spectra don of several hundred stars, some over 150,000 times fainter than the human eye (in dark skies) can see. We managed to do this in all of our planned fields except one, which we had to drop after the attack of the telescope gremlins mentioned in a previous post.  After that first tramautic night, this has actually become a rather “routine” affair, as we spend 50 minutes at a time on one field, then have to scramble to shoot some calibrations or re-configure the fibers on the spectrograph.

It will take us a good chunk of the summer to know what the results of this run actually are, such is the nature of astronomical data, but all in all, this feels like it has been a very productive run. In addition to the “science objectives” of this trip,  I have seen some of the darkest skies imaginable.  Since my interest in astronomy started by my attempts as a 6 to 7 year old to understand our place in the vastness of that sky, it has also been somewhat fulfilling to the soul to see the Universe in this way, the way humans saw it before the advent of artificial lighting.  Call this Chicken Soup for the Astronomer’s Soul.

That said, I am now ready to go back home to my family who I miss and my students whom I have to guide to finals. Just a few more hours, another short 5 hours of sleep, than I take the carryall to La Serena. Dr. Humphreys, my collaborator, will give a talk there tomorrow afternoon. We’ll do dinner afterward, and then tomorrow, I start the 24 hours of flights and connections it will take to get me home.

I got an email today noting that osxutils now installs correctly in MacPorts under MacOS 10.5 Leopard.  I have tested it and this appears to be correct, the commands:

sudo port -d selfupdate
sudo port -d sync
sudo port install osxutils 

did indeed install osxutils as promised.   I also noticed they upgraded from version 1.6 to 1.7, maybe that was all that was necessary.  All the MacPorts packages I used in Tiger now work in Leopard. Now if I could only get a proper recompile of PHP working under Leopard.

One of the neat internal websites you are seeing more and more of at observatories is the use of all-sky cameras to monitor cloud cover. You spend your time in a windowless control room (so as not to let light out) so sometimes you completely miss changes in weather. I downloaded the last roughly 10 hours of video from the all-sky camera here at CTIO and am posting a Flash movie version of it. It starts off with the crescent moon setting (which is bright enough to overwhelm the camera). Then you see the center of the Milky Way galaxy rising in the East, eventually getting very high in the sky.

Since each exposure is 10 seconds, in some frames you see ‘lines’ appear, these are typically airplanes or possibly satellites.

The bright “star” to the East (left) of the Galactic Center in the last few frames is the planet Jupiter. Also in the last few frames you start seeing a glow in the eastern sky, almost pointing toward Jupiter. This is the Zodiacal light, sunlight reflecting off dust particles in the plane of the solar system. You need quite dark skies to see that.

My last observing run at Cerro Tololo, we were observing in “grey” time, when the moon was between 3rd quarter and full. So the dark sky only lasted a few hours. Now we are here during dark time, the days around new moon. Cerro Tololo is a nice, very dark site… perfect for astronomy. There is a bit of light pollution from La Serena and Coquimbo in the east and Vicuña in the north, but the sky is very dark, especially without the moon up. A large part of what makes this site so important to optical astronomy is this darkness, which is a rare commodity in the modern electric light-filled world.

I realize how dark the skies are here every time I go outside now. The Center of the Milky Way is passing overhead and it just screams out at you to be noticed. You can see it clearly on the right side of this picture, shot by Roger Smith of NOAO/AURA/NSF. It shows the 4-meter at Cerro Tololo shot at night. This is what the skies look like here. Admittedly this picture goes a bit deeper than human vision, but I would swear it isn’t much deeper. At home, we can’t see the Milky Way easily, even 15 miles from town, because of the light pollution and the fact that the Galactic Center is very far south. Here, you can’t avoid it! The Large and Small Magellanic Clouds, two irregular galaxies orbiting the Milky Way, are clearly visible to the human eye (they are on the right side of this picture).

And just a few minutes ago I saw something I have never seen before, Zodiacal Light. I am seeing sunlight reflecting off dust grains in the plane of the Solar System. Something only possible because of these extremely dark skies. Cool!

Last night was quite a misadventure for us. First, we lost the autoguiding computer that keeps the telescope pointed at its target. The able engineers here tackled it for over 2 hours, we finally decided to guide by hand… tedious, but possible. Then the fiber controller on our multifiber spectrograph flaked out. Another 3 hours lost in attempts to remedy that. In a 10 hour night, we only had about 4 hours on sources. Oh, and in the last hour or so, something I hadn’t seen at CTIO during my last run happen, high cirrus clouds came in. Blech.

Tonight is starting off better. The clouds dispersed (mostly). The autoguider is working. And while we lost about 45 minutes to fiber issues, it looks like those may be vanquished as well. Hopefully the telescope gremlins that were working against us last night will be gone tonight. We are on our first 50 minute exposure, so I am going to bang out this post quickly.

Here’s some more pictures I have taken around here during the few hours of daytime I have been awake.

This is the telescope we are using, the 4-meter Blanco telescope on Cerro Tololo. This is a stitched image composed of 6 single frames. Because I was relatively close to the telescope, there is a distortion here similar to a fisheye lens image. To get a sense of scale, notice the double doors to the lower right hand side of the telescope itself.

This is an image of the other telescopes on the peak of Cerro Tololo shot from the catwalk around the 4-meter. From left to right the larger domes contain the 60-inch (1.5 meter), 36-inch (0.9 meter), the Yale 1-meter (which I used in April 2006), and the Michigan Schmidt Telescope. There are a few smaller telescopes in the background. About 50 miles behind the telescopes is the La Silla observatory (not visible in this picture).

There were some clouds here earlier today. This is the view from the peak of Cerro Tololo towards Cerro Pachon, which the rightmost mountain in this image. On its peak you can see (as small dots in the thumbnail) the SOAR telescope on the left and the large Gemini South 8-meter telescope on the right. I love the clouds in the background rolling over clouds, towards Argentina.

This is another 180 degree panorama shot from a bit up the hill from the dormitories. It shows Cerro Tololo on the right and on the left, appearing more distant than it really is, Cerro Pachon. If you squint, you might see the Gemini South 8-meter in this image.

Finally, another 180 degree panorama of the western horizon as seen from my dorm room right around sunset tonight. Those pink clouds, illuminated by the setting sun, are over Argentina. They form over those mountains to the west of us, Cerro Tololo rarely sees puffy clouds like those, it rarely sees clouds (except in the winter), and when it does see clouds, they are high cirrus as shown in the picture above.