The past few days I’ve been in Arizona assisting with an install of a new EHT VLBI receiver onto the 12m radio telescope at Kitt Peak. EHT stands for Event Horizon Telescope (which you’ve probably heard in the news after they released their image of the black hole light ring) and VLBI stands for Very Long Baseline Interferometry.
View from a vantage point near my dorm at Kitt Peak National Observatory. KPNO is home to some 22 optical and 2 radio telescopes, making it ” the most diverse collection of astronomical observatories on Earth for nighttime optical and infrared astronomy” according to the KPNO website.
One of my responsibilities, as a winterover (WO) for the South Pole Telescope will be to operate the SPT during the EHT observing run. This will be a ~week long period where VLBI observations are coordinated across many sites, taking into account weather, visibility, etc. WOs are trained at Pole prior to the end of the summer season, but this can be very busy and crammed with information. This year, there was an opportunity to alleviate some amount of information overload by helping set up a new EHT receiver on a 12 meter dish at Kitt Peak.
The 12m dish (an ALMA antenna) in which the EHT receiver was being installed. The South Pole Telescope is only 10m in diameter, but the ground shield probably makes it a contender to the size of this one. The rotating dome is a pretty impressive structure, and has an infra-red tracking system which keeps the dome opening aligned with the telescope as it observes.
Inside the receiver cabin of the 12m. Unlike SPT, the EHT receiver is a single pixel detector, and so it can be quite small. The receivers sit on a suspended rack in the cabin, and in the case here, there is a 4mm, 3mm and 1mm (the EHT) receiver. The 2mm has yet to be installed. Different receivers are swapped in and out of view of the primary beam via a pickoff mirror that can rotate above the receivers (not visible here). On the left is the electronics rack for EHT’s signal digitization.
Inside the telescope’s control room, and an unfortunately timed photo of Professor Dan Marrone, who is in charge of this installation. The other WO candidate, Maclean, was more fortunate. The daytime telescope operator is at his desk on the far-right. The large slanted windows reminded me of some Death-Star-like control room you might see in a movie. Since we were just installing the receiver and checking the signal path, we didn’t have much of a need to be in the control room, but instead mostly crammed into the receiver cabin.
Though we worked past dark most nights so I couldn’t get many good sunset photos, I did manage a few nice sunrise photos! I will post them all below. Enjoy!
Top Left: The author outside his dorm in early morning. Some optical telescopes in the background include the 90″ (white dome) and the 4m (silver dome). Top Right: A quick pick I took during a sunset. Bottom Left: The radio telescopes in early morning from outside my dorm (which was quite a bit higher above the radio sites). Bottom Right: Sunrise behind my dorm, the shadow of Kitt Peak can be seen on the horizon, and the full Moon shines brightly (in fact the moon ruined both observing nights for many telescopes and my own star-gazing ).
Allen's South Pole Winter-Over 2020 (+) 