Weather & Planning. Daniel Duggan

Transcription

1 Daniel Duggan

2 The weather is the single biggest and uncontrollable factor that may affect the quality of your observations or your ability to observe at all. This document will give you an insight to the weather at Faulkes Telescope North on Haleakala, Hawaii and Faulkes Telescope South in Siding Spring, Australia. The two telescope sites are very different and thus have different weather. FTN is 3000m above see level on a dormant volcano and is a very dry site, whereas FTS is only 1000m and much more humid. Immediately you can see that the actual seeing conditions on FTS is not as good as at FTN. This is because there is more atmosphere to look through at this lower altitude as well as more water vapour to look though. FTN - Haleakala FTS - Siding Spring The first place you should look for information regarding weather is at the Faulkes Status page at Most of the information you need immediately before your session can be found there. However, if you would like to find out more about the weather around these two sites including current and future weather conditions then please visit the links on the next page. In particular the two sky cameras are of particular use. Please note that these resources are not operated and maintained by the Faulkes Telescope Project. Page 2 of 6

3 Faulkes Telescope North - Hawaii Haleakala Summit Forecast This link contains hourly and 7-day forecasts of the Haleakala summit. Haleakala Fish-Eye CONCAM This is a very useful camera that points at the sky and takes images every few minutes. It is very useful or showing cloud cover and it labels the more famous and well known objects. Infrared Cloud Monitoring at the MAGNUM Observatory This camera is a wonderful tool for showing cloud cover by measuring the temperature of the sky. Haleakala Observatories Page This is another weather page which shows an animation of cloud movement over a period of 2.5 hours. It also contains data on temperature, humidity, wind direction and speed etc. Page for Haleakala Undeclared This page contains weather hour-by-hour, weekend and 10-day and even monthly forecasts, very useful for planning ahead for a session. Faulkes Telescope South - Australia Siding Spring Fish-Eye CONCAM This is similar to the CONCAM for Haleakala. Zone for Coonabarabran &fn=true This weather page is for a place which is very near Siding Spring, it has data on temperature and humidity etc. Anglo-Australian Observatory Page This page has more animations which show cloud movement over a period of 9 hours. Page 3 of 6

4 Interpreting the Cloud Cameras. The CONtinuous CAMera (CONCAM) images at Siding Spring and Haleakala are part of a network that monitor the night sky around the world and they are very useful for looking at weather conditions. However, they do not use infrared so it is a little more difficult to spot the really high cirrus cloud. This image shows a clear sky above Siding Spring and you can make out the Milky Way clearly to the right as well as the large and small Magellanic Clouds near the bottom left. This is above Haleakala, again the Milky Way is clearly visible. Page 4 of 6

5 This image shows partly cloudy weather on Haleakala. MAGNUM (Multicolor Active Galactic NUclei Monitoring) Infrared Cloud Camera on Haleakala. The CONCAM measures the temperature of the sky, it sees the whole sky with the camera been in the centre of the image and the ground around the outside. The image is circular and when there is no cloud cover the image will be the same brown as the surrounding background. When cloud is in the sky the image goes lighter as the sky gets warmer. The image above shows a pretty much clear sky. It doesn't usually get much better than this. It is possible for it to go totally clear but this is rare. Page 5 of 6

6 This image shows some considerable cloud but not all of it is dense cloud and there are some gaps. Very dense cloud is shown as bright white. Observing in Partly Cloudy Now, I would like to draw your attention to the fact that successful observing can take place during partly cloudy weather. If the sky is too cloudy the telescope dome will close, however, during partly cloudy weather the dome will remain open. Partly cloudy weather may take two forms. It could be that there is cloud present only in part of the sky (for example, in the east and north) or it could be that cloud cover is across the whole sky but is thin enough to still observe through. During telescope commissioning the FT team managed to obtain some successful images during thin cloud cover. These are shown below as examples of what is possible during these sorts of conditions. M27 - The Dumbbell Nebula NGC 7479 Page 6 of 6