Tips from DES Observers

Please add to this non-exhaustive list of non-technical advice and cool details which you may find useful

Practical info

  • The rooms and bathrooms are much nicer than at the Recinto in La Serena. You have a balcony with a fabulous view.
  • There is an excellent washer and drier (you can do a big load from start to finish in an hour and a half) - so don't take loads of clothes with you.
  • Only the rooms closest to the dining hall have wireless, for the rest you'll be on a cable (so bring a dongle adaptor if you don't have an ethernet slot)
  • Mobile signal is poor; texts do get out/in especially in the dining hall (not at all inside the dome - a big metal box!). You'll not be able to have a conversation on your mobile, but skype is fine.
  • Scroll down for info about food.
  • Don't forget to take a flash light with you (there is one on your room key).
  • The rooms and bathrooms are much nicer than La Serena. You have a balcony with a fabulous view. There is plenty of hot water and (unlike ESO) you can even take a bath.
  • Unless you don't mind walking up and down the hill a lot, one person in the observing team needs a car, but not everyone.
  • This rather-hard-to-find document contains some useful stuff written by CTIO (esp. p6+ about safety):

A bit of history...

  • Cerro means “hill” in Spanish. “Tololo” means “closest to the edge” in the local pre-columbian dialect.
    • A CTIO page ( says the dialect is Aymara and gives an alternative translation: At the Edge of the Abyss.
      • having said that, the Aymarans didn't live around here, they're from the other side of the Atacama. The locals were the Diaguita people, or the Changos of the coast.
      • a CTIO astronomer guessed it was Mapuchean, but they live as far way from here to the south as the Aymarans to the north.
      • An Incan army did pass along the coast circa 1475, so maybe Aymarans in that army gave it the name that stuck.
      • research into the origin of the name continues...
    • so Tololo's theme song should be Yes' Close to the Edge?
  • When the telescope was being built, the local farmers were concerned that the astronomers would blow the clouds away from the sky. In fact the shape of the mountain does protect it from clouds (CTIO tour guide, 2013).

Before the night starts

3pm: observer’s “morning”

  1. Cereals are always available in the kitchen and they are surprisingly good!
  2. On Saturday, you can join the tours of the 1.5m and the Blanco, leaving from the dining room at 2ish. There is always English translation available and the guide will probably ask you to say a few words when stopping in the Blanco control room.
  3. There is a gym on the mountain that is surprisingly well equipped - as a staff member how to get to it.

On the way to the Blanco

  1. Be careful, the UV at Tololo is usually off the chart. There should be sunscreen located at the exit to the cafeteria and in the control room near the walkie talkies.
  2. Walk there, and take the shortcut rather than the main road! (if it gets too steep, it means you missed the steps, come back, don’t die, the DES needs you!)
  3. Try to see the “viscacha” (very cute small edible animal). According to Jim, they gather to watch the sunset. (If you disbelieve, stand next to the Rasicam at sunset)
  4. This is the time of the day when foxes try to be your friend and get some food. But alas, in 2016 the foxes went away as the cooks stopped feeding them: "the restaurant was closed", Manuel put it.
  5. Say “Hi” to Rasicam.


  1. The desserts... (try the jelly and the mote con huesillos).
  2. One of the cooks is “el rey de empanadas”. He can give you the recipe.
  3. There is coffee and tea in the cafeteria (and you can make your own in the kitchen at the telescope).
  4. The fruit juice (as is the case everywhere in Chile) is watered-down and sweetened with a mixture of sugar and artificial sweetener. Makes the free Coke from the drinks dispenser seem like the healthy option!

Night lunch sheet

  1. Don’t forget to fill it in by noon (the chefs may not be able to fill it if you hand it to them in the afternoon). In practice, you are best doing it at Dinner the night before, e.g. fill it out on Tuesday evening for Wednesday's night lunch.
  2. Make sure you tick separate columns, or you will get steak and jam in the same sandwich.
  3. The chocolate cookies are the best!
  4. If you ask for tea in your thermos, it is very likely to taste like coffee, so you probably want to ask for coffee. Of course hot water and tea bags are available in the kitchen next to the control room, so if you want tea, you can make it in real time!
  5. Be experimental, it makes the night more interesting: some optional ingredients are VERY surprising.
  6. Be careful filling out the sheet at the end of observing. If you are too tired you may end up with a very experimental lunch the next night (egg and jelly anyone?)


  1. It is customary for observers to wander outside to watch the sun go down (viscachas too).
  2. Sunset is quite beautiful and a great way to meet other people on the mountain
  3. Keep your eyes out for the green flash and Baily beads. Here's some history

During the night

  1. There is a sound system in the control room (but you'll need an aux to RCA cable or CDs).
  2. One of Obstac alarms sounds very much like a chicken.
  3. There is a system that turns the light on inside the room only when the telescope door is closed.
  4. Be a posh observer and say “tonight is photometric” (fancy way to say that it’s going to be a good night of observation).
  5. Make sure you come with the telescope operator at least once when he goes up to open/close the louvers: the dome is all windy, and dark, and noisy from the telescope moving and the nitrogen pump.
  6. When you go outside during the night,
    1. There is some kind of jingling noise from the dome. It is the liquid nitrogen pumping process.
    2. If you go before the moon rises, stay outside for ten minutes and you will see the milky way in all its splendor! If you come from the Northern Hemisphere it is even more impressive! Check out the Magelanic clouds!
    3. It feels very dark and cold but at the same time you know that you are surrounded with astronomers taking observations in all the surrounding domes... this is a good time to be philosophical.