Saturday, January 03, 2009

Night #20 (2009/01/03) Idiosyncrasies of a Dome

I did not mention this, but yesterday we have, for the first time, opened part of the dome that we had not before. The dome "door" is composed of two parts. The bottom part can be opened to allow the telescope to see below 30º of altitude. However, because the bottom part is opened by engaging it to the top one, when it is opened we loose the ability to see near the zenith.

Again tonight we have opened this bottom part for our early night target: WR140, which is setting progressively sooner after sunset. For targets after HD 4004 (WR1) or HD 14134, that are mostly crossing the meridian by the time we point at them, we must close the dome to disengage the bottom part and open again only the top part of the dome window.
There is just this tiny extra "bug" in the process: the bottom part only locks or unlocks itself to/from the top part on certain dome orientations! So we also need to rotate the dome towards North (at least we know it works this way), then close the slit, disengage it, open the slit again, and turn the dome to the new position.
Of course, you can't turn the dome while you are opening/closing the slit, because the motor for that needs to be plugged on one of four wall outlets. For further unneeded details I can say that the slit opening/closing motor operates by wireless control but must "warm up" for a few seconds before it reacts to the remote. Oh and the door to the dome room must be closed!
So the unneeded details on the complete 14-step process to change from a low target to one near the zenith are: close door, rotate dome North, plug motor in, wait a few seconds, press "cerrar" button on the remote, move the stairs to below the slit, wait for dome to finish closing (45 seconds, maybe) while climbing the stairs, safely disengage bottom part of the slit door, climb down from the stairs (the remote does not work with the telescope between you and the receiver), press "abrir" button on the remote, move stairs to appropriate position, start pointing the telescope using the setting circles while slit opens, unplug the slit motor, and finally rotate dome so you can look through the finder and visually finalize pointing the telescope.
Some may not enjoy this, but I do! It makes us be part of the telescope...

The first two weeks (2008/12/14 - 2008/12/27)


The second team at MONS (me and Thomas), for this WR140 Campaign, finished its activities last week. This was a time of not-so-good weather. Many times we had to close the dome, or could not open it. We are not allowed to observe when the humidity rises above 80%, nor when wind blows stronger than 45 km/h. These two charts show humidity and wind speed during most of our two-week stay at the observatory.

Night #19 (2009/01/02) Back to MONS

Today, we got back to the observatory. The weather is very nice: Low humidity, little wind.. This is clearly a measuring night!
The targets for this night were: WR140, HD14134, Eta Taurii (Alcyone), HD42087, HD45314, HD50896 (WR6).

Day #18 (2009/01/01) New year, new trip

Nelson and Eva had not been in Tenerife before, so a trip to the island was again mandatory.. This time we traveled clockwise around the island, instead of the previous trip with Thomas. We first climbed up to Teide, crossed the crater, discented to Los Gigantes for a nice lunch, then crossed the mountainous West of the island, reached Icod de los Vinos, and finally arrived at Puerto de la Cruz in time for not speding much time searching for parking space.

Friday, January 02, 2009

Day #17 (2008/12/31) One less

Yesterday, concern was that leaving very early in the morning would be a problem due to bad weather or ice on the road. A valid concern, on a mountainous climate, high above sea level. We were advised to go through Vila Flor in order to reach the south airport.
We woke up early to take Thomas to airport. Bad weather was gone!
We took the suggested route via TF-21 towards Vila Flor, but as we reached El Portillo a sign told us the road was closed! We came back and went through our originally planned route, through Güimar. This only cost us half hour. All the way, care was taken not to go fast as rocks, ice, or other traps laid by the weather could be present.
Still, we arrived airport at 9:00 and had to wait 45 min for check-in. So our trip was a success.

We then went to our hotel (same as for Christmas), had dinner, and as soon as the new year started we went to bed to commemorate it with sleep! A good way to start a year, I think! There are those who wish to start the year with the right foot, we chose to start it with the right dream!