Hale Telescope Webcam is Back!

It has been a tough spring for the webcam in the dome of the 200-inch Hale Telescope, but as summer approaches I am happy to announce that it is back on line.

I made a slight adjustment on the camera's focus this morning and captured this shot of me with the Big Eye. I will try not to block the view from now on.

Watch the Webcam Today

Here is a capture from the Hale Telescope webcam taken early this morning at the end of a long (12.8 hour) observing session.


Today should be an interesting day to watch the Hale Telescope webcam as we are pulling the 200-inch mirror out of the telescope today so that we may wash the mirror tomorrow.

I'll be posting pictures of the event as they come in.

Cleaning the 200-inch Telescope

If you have checked the Hale Telescope Web Camera in the last few days you may have seen the 200-inch pointed to the extreme north, as it is here in this view from yesterday morning:


This is being done so that the support structure of the telescope can be washed.



It is a tough job, but somebody's gotta do it.

Having the telescope pointed to the extreme northeast, as it is for these shots, certainly gives some unique photo opportunities. Wouldn't you agree?


The work is continuing for a while yet and is not a disruption to nighttime work. Last night, for instance, the telescope saw a full 10 hours of use.

Web Cam is Back on Line

The Hale Telescope web cam had been off line for a couple of weeks. It is up and running again.

The views are pretty good in the daytime, but don't expect to see anything at night as it is far too dark. My favorite views are those that come in twilight, like this shot recorded this morning with the 200-inch looking far to the north.

Engineering Time-Lapse

Here is a time-lapse video that takes the entire first day of engineering on the mirror supports and compresses it into about a minute and a half.

Most of the work during the first day was directed toward preparing the telescope with earthquake tie-downs, removing the Cassegrain cage and preparing for the removal and refurbishment of the mirror supports.

Video on Blogger is somewhat compressed, so if you want to see a larger, 99 mb version, click here. I should have some more of this kind of time-lapse to show off later on. Thanks to Mike V for his help on this!

Mirror Support Engineering in Progress

If you saw the History Photo of the Week, posted earlier today, you know that we are just beginning a major, multi-week, engineering run on the Hale Telescope to clean and refurbish its 35 mirror supports.

You will be able to take peek at some of the action by looking at the Hale Telescope Web Cam. Unfortunately it doesn't provide too close a look at the action, but I will be posting information and updates here on the blog from time to time.

The action so far today has been mostly directed towards preparing for the work to come. The Cassegrain cage should be removed this afternoon which will provide easy access to each of the supports.

Weather Update: The weather on Palomar Mountain is wonderful right now. The engineering work has kept us from plowing the snow from the public parking area so we are still closed at this time.

The Web Cam Difference

I have posted about this before (see The Difference Engine), but if you look at HPWREN's display of the Hale Telescope webcam you can get some cool displays when there is activity going on in the dome.

Here is a shot from a few minutes ago:

and the resulting differential image:


The differential image is produced by subtracting the newest image from the previous one. This is the same technique that is used by the Palomar Transient Factory (PTF) as they hunt for supernovae and other other variable sources. See my post What Does a Transient Look Like? for details on how that works.

200" Web Cam Restored

The dome for the Big Eye was still open when I cam into work this morning which reminded me to tell everyone that the Hale Telescope web cam is back in action. It was out of commission for much of August but restored last week.

The image above was captured this morning during morning twilight as the telescope was looking high in the southeast. The good folks over at HPWREN assemble animations and maintain an archive of images from this and other web cams on their network.

Prime Focus Instrument Change

Here's a movie of a recent instrument change at Prime Focus. A high-resolution version (131 mb) is available here. That's the Hale Telescope's Large Format Camera heading down and the Wide-field Infrared Camera going up. Instrument changes such as this one are pretty common, happening several times each month. What is uncommon is re-aluminizing the 200-inch primary mirror. We only do that every 2 years or so.

On Wednesday, November 12 be sure to tune in to the Hale Telescope's web cam to catch all the action. The 14.5-ton mirror will be pulled from the telescope that day.

Hale Telescope Shakedown

Every once in a while you need to give your telescope a shakedown just to make sure that everything is exactly the way you want it and that it will not move during the night. We gave the Hale Telescope just such a shakedown last week.

And here's a really short movie of the shakedown taken by the Hale Telescope web cam and put together by the good folks at HPWREN.

The Difference Engine

The good folks over at the High Performance Wireless Research and Education Network do some cool stuff with the images that come out of the Hale Telescope's webcam. They grab and archive an image every three minutes and produce time-lapse animations from them. An interesting twist on the Hale Telescope webcam is the differential image that is produced by subtracting the newest image from the previous one. Sometimes the results are pretty cool looking.

Here's a webcam shot taken in morning twilight from Monday. The differenced image is below. From that you can tell the the telescope is slowly tracking across the sky & that the mirror cover closed.

Web Eye on the Big Eye

You never know what you might see on the Hale Telescope's Web Cam. Yesterday offered up this impressive shot of the Big Eye.

The good folks over at HPWREN archive images and even make movie clips from them. Here's a link to the animation from the work taking place yesterday.

The view of from the web cam isn't too impressive at night, but it can be pretty magical right at the dome opens in the evening and closes in the morning. I'll share some good shots from those another time.