Pinned post

It looks like jumping instances killed my old post, so I'll do this again:

An : I'm an astrophysicist ( ) at NASA JPL & Caltech studying at the dawn of time (with the occasional ); a fan of being outdoors (, , , ); a user who dreams of in the USA; an MSU Spartan alum (); and a liberal who just wants a better world, gosh darn it.

Bummed that the Surfliner is shut down from LA to SD. That is a gorgeous stretch of rail, and the views are some of the best on the West Coast. Even with repairs, I'm not sure how much longer they'll be able to keep it going, though.

Yessss, #AB2097 passed! No more parking minimums within a half-mile of public transit, statewide. That is a huge step away from car culture in California.

Excessive parking discourages residents of new housing from riding transit, even more than good transit encourages it. (So found this study: sightline.org/2021/01/28/more-)

An important thing I learned recently is that some of Heidelberg's tram routes are greened. Now to get rid of those pesky car lanes!

Today was a rush; losing the first two-thirds to bad weather, I was blitzing as fast as I could to get the most out of the night. Lots of short visits, churning through a target list as fast as I could. Some nights, there's 45 minute exposures stacked back-to-back, and you can slowly work your way to dawn; other nights are like today, when you barely have time to do anything but observe.

Tonight went fine for me, but, if you want a good story about what can happen when you're trying to get through such a sequence, have a listen to George Preston reminiscing... youtu.be/pXl4BOjoiN0?t=2967

Show thread

We have now entered twilight. The sky is going to start growing brighter; faint objects will become lost in the glow, the telescope will not be able to correct its seeing as well, and eventually there will be no guide stars bright enough to keep the telescope pointed accurately. When in the morning one chooses to call it a night is a function of many variables; for me, I was out of bright targets and I can see the blue in the sky already.

Show thread

While pretty pictures are why people get excited about astronomy, tonight's work is far from that. Instead, I'm taking spectra of objects to classify them. In short, take the pretty image of the night sky you probably wish I was taking. Then put a dark band across it. Line that band up over the object you're interested. Now, that band is dark because you're not sending that light to your imager -- you're going to disperse it.

So you have a line of the night sky coming in through your instrument. Break it apart -- blue to the left, red to the right. Now you have a spectrum. All those vertical lines -- those are night sky emission lines. They're a single wavelength of light, seen across the entire sky. That horizontal band in the second image is the galaxy we're interested in, stretched in flux from blue (left) to red (right).

Show thread

Finally! Photons are hitting the CCD! Science will yet be done tonight (and Grim Fandango needs to take a break until tomorrow...)

Show thread

Alright! Things are looking a lot better up here. The humidity has dropped to ~50% and the sky is clear. The TO (Telescope Operator) has checked and the dome is mostly done dripping. Once we're a little more confident in the weather, we may get to open up! That being said, I've only got two, two and a half hours of night remaining...

Show thread

The current all-sky camera view; as you can see, there doesn't appear to be too many clouds between me and freedom. However ... those are water droplets all along the camera. It seems like humidity continues to be a problem. The telescope operator is currently checking to see if there's water dripping into the dome.

But, speaking of humidity, I've made some coffee! Mountain coffee is generally not the best, but, being at home, I can freshly grind and brew up some locally-roasted beans.

Show thread

It is at this point that I look to see if works well on the ...

Well, it's getting a little better. Currently, there's still haze out -- compare to an image the same time of night from a few weeks back. They don't open the dome if the humidity is too high, and they don't open the dome if there are clouds overhead, and they DEFINITELY don't open the dome when there's fog. So, even if we can get this nonsense out of here, there's no telling when or if the dome is going to open tonight.

Show thread

We're, uh, having a spot of a problem right now, though. Here's the view from the HPWREN camera (hpwren.ucsd.edu/cameras/HighPo) on High Point Lookout. This morning, there was a nice view of the telescope dome (center left), which, over the past two hours, has turned to pea soup. Telescope domes don't open when there's fog, and, unless this clears out, I'll be spending tonight watching Netflix.

Show thread

As I said, tonight I'm on the 200-inch (that's the diameter of the primary mirror) telescope on Palomar mountain in southern California. The Hale telescope, to use its proper name, was once the largest optical telescope in the world. It's also a giant, in a way that even larger, modern telescopes are not. Nowadays, we can stack some pretty impressive telescopes in relatively smaller domes, but construction of this started before WWII. It is, in some ways, the last of the Telescope Battleships.

First light occurred in 1949. But in June, 1948 there was a large dedication ceremony. Photos from that event really drive home just how freakin' big the whole thing is.

Show thread

It's time for my favorite part about being an astronomer: an observing night! Tonight, I'm on the Palomar 200 inch telescope, although I'm doing the observing from home. I've been a bit swamped with other things to talk too much about , but tonight's the perfect opportunity to get back into it.

So, for the next twelve hours, let's enjoy the fun!

Show older
Mastodon 🐘

A general-purpose Mastodon server with a 1000 character limit.

Support us on Ko-Fi Support us on Patreon Support us via PayPal