Archive for the ‘Mt Wilson’ Category


Impromptu binocular digiscoping

January 18, 2017


I grew up in Oklahoma, on the Great Plains. The plains have a wild, forlorn beauty, but I have always craved seeing mountains. When I was a kid, that meant waiting for a family vacation to the Rockies or the Black Hills of South Dakota. I have been very fortunate that since moving to California in 2001, I have essentially always lived within view of mountains. In Santa Cruz and Berkeley it was the coast ranges, which are really more like ambitious hills. In Merced it was the Sierra Nevadas, which are legit, but not particularly close to Merced. The mountains were only visible as a low line on the eastern horizon, and only when the air quality was good, which was not often. Fortunately that was just one year.

Since 2008, I’ve had the privilege of living at the feet of the San Gabriels and especially Mount Baldy (formally Mount San Antonio, but universally ‘Baldy’ to locals), which looms directly north of Claremont like a slumbering god. So I get to see proper mountains – the San Gabriels are still rising fast so they are impressively steep, and Baldy tops out at 10,064 feet (3068 m) – pretty much every day that it’s not raining and there are no nearby wildfires. In the winter the mountains are often snowcapped, although never continuously so, it’s just too warm here.


A couple of days ago I was out running errands and the mountains looked so good that I had to drive up to the top of the First Street parking garage downtown to get some unobstructed photos. Off to the northwest, 22 miles distant, I could just make out the gleaming white domes on Mount Wilson. Then I remembered that I had my 10×50 binos in the car, so I got them out and spent a few pleasant minutes scanning the whole northern skyline, from Mount Wilson in the west to mount San Gorgonio, above Big Bear, 51 miles due east.


Then I got to wondering – if I held my iPhone up to the binos, would I be able to get a recognizable photo of Mount Wilson? It was worth a try. I had to prop the binos on my sunglasses to get the angle right, and the raw shot is vignetted because getting the camera-to-eyepiece distance correct is a little hairy, but hey, there are the domes.


Here’s a cropped, tweaked, and labeled shot. Except for the CHARA Array, an optical interferometer using six 1-meter telescopes in small domes that started work in 2002, all of the historically important installations are visible from 22 miles out.


I also got some shots of the nearby peaks, especially the higher foothills of Mount Baldy. This shot is a pretty good match for the last photo in this post, which was taken through a different instrument at a different time of day in a different season, but focused on the same peak. This peak is 10.5 miles from my house, as the crow flies, so about 10.25 miles from the Claremont parking garage where the photos in this post were taken.


Cropped and tweaked. Not too bad for 10×50 binos that cost less than $30.


Mt Wilson photo tour and a brief observing report

June 5, 2016

Mt Wilson 1 - Geo on the 60-inch

Last night the PVAA had the 60-inch telescope booked at Mt Wilson. It had been ages since I’d been up there – my only other trips up were in 2009 and 2010 (observing reports here and here). So it was very satisfying to be back. It is amazing to look back and realize that in 2010 I was only 3 years into what has now been almost 9 years of stargazing.

The last two times I went up, we didn’t have time for a tour of the grounds, so about all I saw were the parking area, the 60-inch dome, and a few odds and ends in the distance. This time we got a nice long tour from Geo Somoza – most of the rest of this post is a photographic tour of part of the observatory. We didn’t have time to go through the museum up there, or see the solar telescopes – guess I’ll just have to go back again to catch those (which is no bad thing!).

I rode up with Ron Hoekwater, Laura Jaoui, and Gary Thompson, who kindly drove us. We left Claremont early and got up there about 6:00, well in advance of the planned 6:30 start time for the tour. While we were chatting outside the gate, we saw something ominous: a tower of smoke going up from the mountains to the west. This would come back to haunt us.

Mt Wilson 2 - Einstein bridge and the 100-inch

Here’s the dome of the 100-inch Hooker telescope – world’s largest from 1917, when it eclipsed the 60-inch telescope on the same mountain, until 1948, when it was eclipsed in turn by the 200-inch Hale telescope on Palomar Mountain. It is a bit staggering to realize that from 1908 to 1993, when Keck 1 went online on Mauna Kea, the three consecutive world’s largest fully-functional telescopes were all within 92 miles of each other in southern California. (The 240-inch Soviet BTA-6 saw first light in 1976, but it suffered terrible thermal stability and seeing problems and never performed anywhere near its full potential.)

This bridge is nicknamed “Einstein’s bridge” because Einstein paused here for a famous photograph during a visit to Mt Wilson in 1931 – see that historical photograph here.

Mt Wilson 3 - the 100-inch

Here’s the scope itself, the same machine that Edwin Hubble and Milton Humason – a former mule-driver who worked his way up to master observer – used to chart the expansion of the universe. I was scheduled to go up and observe with the 100-inch last year, but I got very sick the day before and couldn’t make it. So that is still on the bucket list.

Mt Wilson 4 - the 100-inch mirror

A view into the back of the mirror cell of the 100-inch telescope. The green champagne-bottle glass of the primary mirror is clearly visible. If you click through to the full-size version you may be able to see bubbles in the glass. The 14-inch-thick mirror had to be made in three separate ‘pours’ of molten glass, and bubbles from the first two pours were trapped by the layer above. The people at Mt Wilson were so concerned about the bubbles interrupting the figure of the mirror that at first they refused to work with it, but St Grobain Glassworks was unable to pour a better one and eventually George Ellery Hale ordered his people to grind and polish this mirror, which turned out to be fine at the optical surface after all.

Mt Wilson 5 - 100-inch eyepiece

In the old days, to observe visually with the 100-inch you had to go down a narrow hallway to a tiny room where light from the scope was bounced to the Coude focus. That was pretty unsatisfying so a few years ago the telescope was modified for more intimate visual observing. Now the primary mirror at the bottom of the scope bounces the light to a secondary up in the upper cage, thence to a tertiary at mid-tube which directs the light out to a quaternary mirror in the diagonal housing at the top of the black tubular assembly on the left of the scope in the above photo, thence down to a quinary mirror at the bottom of the black tube, then into the white refractor that is pointing down and to the right. A diagonal sitting nearby can be placed into the refractor to put the eyepiece into a convenient orientation when the scope is tilted.

Mt Wilson 6 - 100-inch controls

The control board of the 100-inch, with at least three separate control systems lined up right to left in order of age. Most interesting is the old table on the right with the clock and the two periscopes. The periscopes allowed the telescope operator to see the telescope’s setting circles. Nowadays, the scope is controlled by the computers on the left.

Mt Wilson 7 - 100-inch dome

Excited amateur astronomers lingering outside the dome of the 100-inch. We got to walk around on the walkway you can see on the outside of the dome. The entire dome rotates, walkway included. It’s a fearsome engine indeed.

Mt Wilson 8 - CHARA array and 60-inch domes

On the left is one of the six domes of the CHARA array, I believe still the world’s longest-baseline optical interferometer. It has enough resolving power to image the discs of nearby stars. On the right is the 60-inch dome.

Mt Wilson 9 - lightspeed test site

Geo shows us the concrete pier used during the speed-of-light experiments in the 1920s. More on those in a sec.

Mt Wilson 10 - lightspeed test plaque

For decades in the late 1800s and early 1900s, Albert Michelson conducted a series of experiments to measure the speed of light. In a series of famous tests in the 1920s – almost two decades after Michelson earned his Nobel Prize – a beam of light was bounced from this pier on Mt Wilson to a mirror on Lookout Mountain, one of the foothills of Mt San Antonio, better known to locals as Mt Baldy – the mountain at whose base I live. The concrete pier on Lookout Mountain is still there and it is apparently an easy hike. It’s on my to-do list.

Mt Wilson 11 - LA and smoke from wildfire

Sunset over LA. On the left, the marine layer of fog is moving in over the city. On the right, a tower of smoke is going up from a wildfire near Calabasas, about 40 miles to the south and west of Mt Wilson, and spreading out over the LA basin. For a while the smoke was going southeast from the fire, and it looked like it might miss us. But by the time it was getting dark, the wind had shifted and was carrying the smoke directly toward the observatory.

Mt Wilson 12 - going up to the 60-inch

As darkness fell, we trooped into the dome of the 60-inch telescope.

Mt Wilson 13 - Edison bulbs

Here are the controls for the dome’s shutter, which has to be opened for the telescope to see out, and closed again to protect the telescope during the daytime and in inclement conditions. The three light bulbs on the upper left of the console are original Edison bulbs – they have been working without ever being replaced since 1907 or so.

Mt Wilson 14 - control board and mercury tank

Our telescope operator, Christopher Burns, checks something on one of the computers in the control center, while beyond him Geo stands by the mercury tank in which the 60-inch telescope floats. Don’t worry, it’s fully sealed now. In the old days, it was open, and mercury would sometimes splash on the floor as the telescope rotated.

Mt Wilson 16 - Jupiter with blue filter

Our first target was Jupiter. As usual, the photo completely fails to do justice to the naked-eye view. The seeing was imperfect and I think the smoke from the fire might already have been affecting the views. The north and south equatorial and temperate belts were visible, and the Great Red Spot was prominent, but I could see little detail beyond that. I have seen much better on other visits, and indeed in much smaller scopes (see for example the two previous Mt Wilson observing reports linked at the top of this post). But I won’t complain too much – part of the joy of observing with the 60-inch is in the process, not the outcome.

Mt Wilson 15 - 60-inch lit by laser

After Jupiter we moved on to the globular cluster M3, and then the Sombrero Galaxy, M104. M3 was already looking a bit dim – certainly not as bright as it appeared in Ron’s 25-inch scope from RTMC last weekend – and about this time the smell of smoke became pronounced in the dome. We had a hurried look at M104, but it was just a dim smudge of light and I couldn’t even make out the dust lane.

After M104 we had to shut down early to protect the telescope. If ash from the fire was allowed to fall on the mirrors, it would combine with moisture in the air to produce acids which would eat away the coatings. In the photo above, Geo is shining a laser up through the optical train to check for ash on the mirrors.

Mt Wilson 17 - Matt with the telescope

It was a bummer to have to shut down early, but we had an awesome tour and it was fun to observe again with the 60-inch, even if only briefly. Geo and Chris were great hosts and everyone had a good time. We’ll get to reschedule our night on the scope, since we only got about an hour and a half of observing in, so the club’s investment is protected. It’s a shame about Mars, though – we won’t have another opposition this close for some time, and the planet will be noticeably more distant, smaller, and dimmer by next month already. Still, into every observing career a little rain – or ash – must fall, and I’ve been extremely fortunate. Two eclipses (2012, 2014), a Venus transit, and a Mercury transit in the last four years, and not one of them clouded out. Mars will be back, and I’ll be ready.


Mt Wilson: even better the second time around

June 14, 2010

About a dozen of us from the Pomona Valley Amateur Astronomers spent Saturday night observing with the 60-inch telescope up on Mount Wilson. A really excellent night on the mountain is a Goldilocks affair–you need enough of a marine layer to cover up the lights of LA, but the fog has to stay low enough not to swamp the observatory itself. The PVAA visited Mount Wilson last summer, but got fogged out. That worked out okay for me, because they rescheduled for the fall and I found out about the trip in time to go along.

Saturday night the marine layer was looking  pretty good when we got there. Unfortunately, it cleared out before midnight, so the sky was too bright for us to do any serious galaxy observing. But we saw quite a few planetary nebulae and globular clusters, which punch through the light pollution better than most galaxies.

We saw a lot of burnt trees on the way in, from last fall’s Station Fire, which at one point threatened the observatory. The trees by the gate had some light charring down near the bottoms of their trunks, but they hadn’t burned very high or very hot, and I suspect that the fire evidence I saw there was caused by backfires set by the firefighters who saved the observatory.

The 60-inch telescope, largest in the world from 1908 to 1917, is as impressive as ever.

Our first target was Saturn. Although the seeing settled down later in the evening, right after dark the sky was pretty turbulent and that cut down on the amount of detail we could see. Also, and to my immense irritation, I couldn’t get my camera to focus with the optical zoom engaged, so I couldn’t  increase the object size on the CCD as much as I would have liked. This photo doesn’t really do the view justice–in fact, it’s not much better than I’ve done with my 10-inch scope from my driveway (proof here).  Remember that this is a sad comment on the state of the just-past-sunset atmosphere and my finicky camera, and not a slight on the telescope, which is capable of much better!

But things did get better as the evening progressed and we saw tons of cool stuff. Several other people were experimenting with their own digital cameras and that inspired me to try some things I haven’t done before, like photographing double stars. Here is Albireo, a summer favorite that is easily split by even small telescopes.

We started with Saturn and ended with Jupiter; the King of the Planets was climbing in the east as the sky started to brighten before dawn. If you haven’t looked at Jupiter in a while, the Red Spot is actually red again, and the normally-brown South Equatorial Belt has faded almost completely. This is a big switch from the past year or two, when the “Red” Spot has mostly been visible as a white notch in the SEB. It was far and away the best look at the GRS that I’d ever gotten.

The highlight of the evening for me was seeing M13, the Great Globular Cluster in Hercules, and M5, another excellent summer glob, back to back. M13 is probably in most deep sky observers’ top ten, but some people like M5 better, and I’m in that camp. M5 isn’t quite as big or bright, although it comes very close, but it has a much more compact core and the outer stars are arranged in loops and swirls rather than radiating chains. To my eyes, M5 looks like an explosion of stars, in progress. It’s good in my ten-inch scope. It’s phenomenal in the 60-inch.

Last fall we went on a weeknight and I had to leave early, around 3:00 AM or so, to get up to teach the next morning. We also had a considerably larger group, so we didn’t get through as many objects per unit time. Obviously going with a big group is better for the club, but it was nice to have a more intimate group and a shorter line at the eyepiece. I had a heck of a good time, and I plan on going back up every chance I get. If it’s within your means, you should do likewise.

Many thanks to our host and telescope operator for another tremendous evening!

Update: I’m kind of a doofus. If you were wondering why this post is included in the binocular category, it’s because I took my 15×70 bins with me and did some deep-sky observing out of the opening in the dome, while waiting in line for the eyepiece. I bagged four targets for the AL Deep Sky Binocular club, which leaves me with only six more needed to complete that list. But I forgot to mention all of this when I first posted!


Observing Report: Mt Wilson!

August 22, 2009
1 - LA from Mt Wilson 1200

The LA Basin from Mt Wilson. The yuckiness is partly fog, partly smoke from forest fires, and partly the exhaust of a few million automobiles.

Looking toward the ocean at sunset. The fog helped suppress light pollution from LA while we were observing.

Looking toward the ocean at sunset. The fog helped suppress light pollution from LA while we were observing.

The antenna forest outside the observatory entrance. The top of the solar telescope tower is visible in the distance on the left.

The antenna forest outside the observatory entrance. The top of the solar telescope tower is visible in the distance on the left.

The immense dome of the 100-inch Hooker telescope looms through the trees like a mountain.

The immense dome of the 100-inch Hooker telescope looms through the trees like a mountain. Edwin Hubble used this scope to discover the redshift of distant galaxies and the expansion of the universe.

A closer look at the solar telescope, which was the first operational telescope on Mt Wilson. Hale used this scope to discover the Sun's magnetic field.

A closer look at the solar telescope, which was the first operational telescope on Mt Wilson. Hale used this scope to discover the Sun’s magnetic field.

We started observing with the Mt Wilson 60-inch at about 8:15 PM Wednesday evening. We aimed at Arcturus first, just to make sure that everything was in good working order. Then we split a nearby double star, Epsilon Bootes. After that we got started in earnest. Our first deep sky object (DSO) was M13, the great globular cluster in Hercules. This vast sphere of several hundred thousand stars was discovered by Edmund Halley in 1714. It has special significance for me because it was the first object I observed through the Great Lick Refractor on September 15, 2007, on the night that my lifelong interest in astronomy finally caught fire. In the 60-inch telescope M13 filled the field of view. It almost exhausted the eye, there was so much to  look at.

Here we go--the dome of the 60-inch telescope.

Here we go–the dome of the 60-inch telescope.

Then we went outside at about 9:20 to watch an Iridium flare–the sudden brightening of a giant solar panel on one of the Iridium communications satellites. It was the first time I’d seen one, and it was pretty cool.

Finally, the big gun itself. When you're in the dome, it's about all you can look at.

Finally, the big gun itself. When you’re in the dome, it’s about all you can look at.

Then it was back inside for more telescopic goodness. Post-flare we looked at NGC 6543, the Cat’s Eye Nebula. This is another summer to early autumn classic, and another object that I first viewed through the Lick Refractor almost two years ago. It was even better in the 60 inch telescope, a visibly S-shaped swirl of green with hints of structure  around the central star.

Arf--dunno how this caught me without a smile. I had one plastered on for the entire evening.

Arf–dunno how this caught me without a smile. I had one plastered on for the entire evening.

Then it was on to Jupiter, which was huge. The visible Galilean moons were not just points of light in the eyepiece but little spheres; they looked like the worlds that they are. An odd side effect of looking through the giant telescope was to make us appreciate our own scopes more. For picking out detail on nearby objects like Jupiter, atmospheric turbulence is often more limiting than telescope optics. I’m not going to lie and claim that the views in my 6-inch telescope are as good as the views through the Mt. Wilson 60-inch–but on Jupiter I reckon that the 60-inch scope delivered twice as much detail as my scope, rather than the ten times more detail that optical theory would suggest. If the 60-inch was up on Mauna Kea and not plagued by light pollution, smog, and turbulence, it would perform a lot better–as would any telescope. I’m not complaining. Just observing that although our backyard scopes don’t show nearly as much as big observatory scopes, they still show quite a bit.

When the big scope is pointed straight up you can sit in a chair to observe, but most of the time we were up and down the ladder to reach the eyepiece.

When the big scope is pointed straight up you can sit in a chair to observe, but most of the time we were up and down the ladder to reach the eyepiece.

There was another way in which the views Wednesday night made me appreciate my own telescopes more. Galileo discovered the moons of Jupiter, and he never saw them through a telescope with a diameter of more than an inch. The finderscope that I use on my airline-portable travel telescope has a bigger aperture and sharper optics. And yet Galileo changed the world with the observations he made through his tiny, optically terrible telescope. To get to see the Galilean moons as little worlds in the 60-inch reinforced how ridiculously fortunate all of us are to have such nice tools available.

When you go downstairs from the observing deck to use the restroom, you go past a bank of lockers. The names include Zwicky and Minkowski. This one belonged to Edwin Hubble.

When you go downstairs from the observing deck to use the restroom, you go past a bank of lockers. The names include Zwicky and Minkowski. This one belonged to Edwin Hubble.

Speaking of tools, we got to take turns photographing Jupiter through the eyepiece. As is often the case, I got my best picture in the first few snaps. I was so busy previewing my pictures and talking with the other visitors that I completely missed the next object, planetary nebula NGC 7662, the Blue Snowball. Many thanks to Tom Mason, our scope driver, for sharing the photo below.

Planetary nebula NGC 7662, the Blue Snowball. It consists of vast rings of gas blown off by a dying star. Our sun may look like this in about 5 billion years.

Planetary nebula NGC 7662, the Blue Snowball. It consists of vast rings of gas blown off by a dying star. Our sun may look like this in about 5 billion years. This photo is by Tom Mason, our scope driver for the evening.

Faint DSOs require light-gathering ability primarily and not the resolution of fine details. The 60-inch totally blew away any backyard scope on planetary nebulas. After the Blue Snowball we checked out another, even more famous planetary nebula, the Ring Nebula or M57. In backyard scopes it looks like a perfect little doughnut of gray smoke. In the 60-inch it was a huge and green, with threads of gas and dust visible in the middle. I could even make out the central star, which is a legendarily tough object to detect visually.

After the Ring we went back to Jupiter, and then on to Neptune, which is currently close by Jupiter in the sky, just as it was for Galileo four centuries ago. Neptune is incredibly distant, 4.5 billion kilometers away. That’s 30 times farther from the sun that we are, and 6 times farther away than even Jupiter. Even in the 60-inch Neptune was small, but it was visibly a sphere, which is quite an achievement for any Earth-bound optical telescope. Coming down the ladder, I had to remind myself that Neptune is now the most distant planet in the solar system, since Pluto was (correctly, IMHO) demoted to dwarf-planethood.

The final object I observed through the big gun was the Saturn Nebula, NGC 7009, another planetary. It looked much like its namesake. Click on the link above, get 10 feet back from your computer, and you’ll have a pretty good idea of what I saw through the 60-inch.

The highlight of the evening for me: Jupiter and its moons. Three of the four Galilean moons were visible in the eyepiece, but this photo only shows one: Io, on the upper right.

The highlight of the evening for me: Jupiter and its moons. Three of the four Galilean moons were visible in the eyepiece, but this photo only shows one: Io, on the upper right.

By the time I’d gotten down the ladder from looking at the Saturn Nebula, it was 3:00 AM and time for me to skidaddle; I had to teach Thursday morning and that meant getting at least a little sleep. On the way out, though, I did stop long enough to enjoy a view of the newly-risen Pleiades in my binoculars. You can do the same if you’re willing to get up in the middle of the night–or you can look forward to a Pleiades mission here in a few months. It all comes back around.

Lots of things came back around for me Wednesday night. M13 and the Cat’s Eye ushered me into astronomy, and it was great to revisit them with two years of knowledge and experience under my belt–as well as 24 more inches of aperture.

What I wanted most from the evening, though, was to photograph Jupiter and its moons. They were the first things I ever viewed through a telescope, in my high school astronomy class. They were also among the first things that Galileo observed with his telescope, 400 years ago this December. I wish he could see how far we’ve come–and how much we owe him.

Finally, a huge thank you to the Pomona Valley Amateur Astronomers for inviting me along and being such gracious and interesting hosts. I had the time of my life. If you ever get the chance, go.