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Observing at Sutherland, December 2014

I applied for a week of time on the 1-meter telescope at Sutherland, South Africa. This isn't a large telescope by today's standards, but it's enough to measure the brightness of tiny rocks far from the Earth. I went out with my Honours physics student, Dan Morris, for a week in December 2014. We used it to take light-curves of a handful of Near-Earth Asteroids (NEAs) that were close, bright, and unstudied. We had great weather, which usually meant that I would have been at the telescope observing... but thanks to having him there, I was able to take some night-time photos as well.

This work was funded by NASA, and was done in collaboration with Vishnu Reddy (also at PSI).

This was my third trip to Sutherland since we've been in South Africa, and the first trip where I didn't get snowed on... check out the photos from my other observing trips.


Slideshow (big images)

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Ela at the 0.5-meter

Polish grad student Ela Zo observing at the 0.5-meter at Sutherland. She is the very last person to ever use this telescope at its current site... as of Februrary 2015, it will be dismantled and given away to the observatory at University of the Free State in Bloemfontein. The dome is staying put: in its place will be installed MeerLICHT, a new 0.6-meter optical telescope which will track the pointing of the massive Square Kilometer Array (SKA) radio telescope. The largest portion of the SKA will be centered not far from here outside of Carnavon, South Africa.

Ela is using the photometer to measure stellar brightnesses. This is not a very modern telescope or instrument... every 90 seconds, her photometer beeps, and she has to come out of the warm room, climb the ladder, find her target, repoint, and start the integration again. Dan and I could be asleep while our observations were running... but she climbs that ladder and uses the eyepiece hundreds of times a night.

Her advisor says if the weather is clear she must observe, so no breaks for photos! I took this one in real-time as she was observing, using a composite of 30-second exposure for the sky and dome, and a shorter one for her face at the telescope, illuminated with an orange flashlight.

The red glow across the dome comes from those analog setting circles - no computers driving this telescope!

I just put this one first because I love the photo -- now on to the rest!.

Daytime tour of SALT

We walked over to the Southern African Large Telescope (SALT) to see what was going on. I had some Pluto observations with it earlier in the year but nothing running now. We found Keith, an electro-mechanical engineer, who showed us around.

That's the 11-meter SALT primary mirror at the center. It is made of 91 1-meter hexagons. SALT is a bit funny in that it can't point up/down -- it only spins around on its base. This makes scheduling harder, but it still keeps busy. It also means that what would have been a a $100M telescope could be built for $20M instead.

NB: Mosaic from ten wide-angle shots... SALT's trusses are not really curved like this!

My physics honours student Dan Morris, with Lauren, a chemistry student. Both are at University of Pretoria.
One of the technicians servicing the instrument payload at the prime focus. The primary mirror is below, and all of the instruments are up top. The only exception is the new High Resolution Spectrograph (HRS), which is sitting in a room in the basement. How does it get its light? It's fed by a long fiber optic cable from the primary... in fact, the black thing that looks like a loose power cord danging through the center is the HRS feed.
Looking up from the bottom... all of the electromechanical systems to support the SALT primary mirror.
Keith has taken us down into the basement. We enter what looks like a thick insulated walk-in freezer. What do we have here inside of that? Another gigantic styrofoam box! Inside of this is another box, and inside of that is the optical bench for the HRS spectrograph. The idea is to keep it temperature-controlled to 7 millikelvins (!!). This lets it do super-precise spectroscopy... the goal is to be able to measure radial velocities to 1 meter/second.
Keith with Hannah Worters, a part-time SALT Astronomer, in the control room.
Keith has on his climbing harness to go up!

Walking Around the Plateau.

Outside, we run into John Stoffels, one of the technicians on the small telescopes (that is, the SAAO 0.5m, 0.75m, 1m, 1.9m).

The next time I saw John it was 1:30 in the morning... Eskom gave us several short power outages, and the 1-meter's tracking system didn't recover well, so we had to wake him up to fix it!.

We walk over to the new Korean Microlensing Telescope Network (KMTnet). Bruce and Dan are working on installing the telescope's main instrument, a wide-field imager, which they've built at home at Ohio State. Those are coolant lines coming from the ceiling. The telecope itself you can see, zenith-pointed, through the door at back.
We wander over to the MASTER telescope, a very unique Russian system. It's just been installed, and Evgeny Gorbovskoy is working to polar-align it.
Oleg Gress is working with Evgeny.
Oleg and Evgeny in their building... this used to house an older Korean telescope that was decommissioned.
Walking back down to the hostel from the plateau, with SALT in the background.

Approaching sunset...

It's the middle of summer (uh, December), so the sun goes down late... dinner at 17h30, and we head up to the telescopes around 18h15. The sky is dark enough to start taking flats around 19h30.
Driving up the short distance to the plateau, the 1.9-meter is at left (moved 800 km from Pretoria in 1976!), the 1-meter is open on the right, and Fred is in the bakkie.

KMTNet is on the far right, and the German MONET telescope is in the barn. The soon-to-be-gone 0.5-meter is just to Fred's left.

My favorite guy at Sutherland... Fred started 25+ years ago as an observer developing photographic plates. "My wife would smell the developer all over my clothes and ask me, Fred, what sorts of chemicals do they make you use up there?" From there, he moved to the other telescopes at Sutherland, and has spent years on all of them.

Now he's one of about 6 people who operate the 10-meter SALT telescope. But in twilight before SALT opens tonight, the atmospheric seeing monitor (MASS/DIMM) needs fixing, so Fred's on the ground picking out calibration stars with his naked eye that I have no hope of finding.

Bruce walks back from visiting the Russians at MASTER. I think the two others there are the Polish SOLARIS robotic telescopes.
Beautiful open-air cooling on the Japanese Infrared Survey Facility (IRSF)!
The trio of Las Cumbres Global Observatory Telescope (LCOGT) telescopes, just opening up.
And Dan is at the 1-meter, getting us started for the night, or at least waiting to take flats. (You can see him just to the left of the dome taking pictures.)
Dan and Lorraine watching the sunset next to that Zulu hut.
Waiting for it to get dark, I walk over to MASTER. It's a crazy giant pair of binoculars. They are not even always aligned... there is a servo (visible at center) that will splay them apart by a few degrees, or co-align them. You can also see the pair of Canon camera lenses they use here as finderscopes.

This is a wide-field telescope to search for optical transients: gamma-ray bursts, supernovae, exoplanets, and so forth.


During the first half of the night, the sky is super-dark.. Sutherland is a great site for dark skies.
15-minute exposure looking toward the south celestial pole. The blobs are the Large and Small Magellenic Clouds (LMC, SMC). Francois is in the 0.75-meter in the foreground, which you can see has rotated during the exposure.
We're in the 1.9-meter waiting for our asteroid targets to rise. That's Orion silhouetting the secondary... you can make out the glow from the Orion nebula. The 'warm room' is through the lit door at the right, below the telescope.
Moon coming up around midnight next to the 1.9-meter.
Long exposure at the IRSF... you can see the dome rotating here.

All the shadows, foreground lighting, and blue sky are from the moon... even at half-phase, it's bright.

LCOGT and the southern sky... you can see the Google-inspired colors on the power shed in the foreground. These 1-meter telescopes are part of about a dozen telescopes across the world, all run by LCOGT, allowing (in theory) 24-7 observations of the same target using the same aperture and instruments. The $50M project is privately funded by a former Google exec.
My student Dan has a quick smoke in front of the 1-meter... although unlike Percival Lowell, he does go outside the dome. (Lowell's photographic plates of Pluto are famously contaminated by pipe smoke.)
Dan and I had a week of great observing... we spent most of our time taking light curves of a pair of small near-Earth asteroids (NEAs). This is the warm-room; the telescope is just outside. Laureng never quite adapted to the night-time schedule....

You can see the time on the wall: 3h05 UT. We're almost done for the night... twiilght starts in just 45 minutes! My last run was in May, when the nights were much longer... here, with our target already setting at HA=4:18:15 (that is, 70 degrees from the meridian), it's about time to close up anyhow.

Heading back down...

Driving back town to Sutherland and Cape Town... the hostel is at the far left on the saddle, with two other observatory buildings below it. SALT is the big telescope, with the rest above.
Driving through the town of Sutherland...
If we would have known that asteroids were so close, we might not have had to use the telesope....

[Ceres is the name of the first asteroid ever discovered, and also a town en route to Sutherland. Actually, it's only on the route if you take a 160-km detour on a dirt road... Dan and Lauren can tell you all about it.]

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Henry Throop

Last modified Fri Jan 23 14:03:48 2015