Sorry for no posts recently, but I have a lot of things to do, so I am usually to tired to write anything (though I have some topics I would like to talk about). So for now, please check out the first images and movies from NASA’s Solar Dynamics Observatory.
(This mission was the topic of my Ad Valvas seminar at the Institute in March just before I left to La Palma for two weeks.) Click on the image for the SDO First Light Gallery @ Goddard Space Flight Center’s Scientific Visualization Studio.
First of all, thanks to DC Rainmaker for – accidentally – reminding me with his latest post, to write about this. (BTW, very interesting blog, strongly suggested if you are into cycling, running, swimming or triathlon.) So with the Garmin Edge 500, the user can cycle through 3 main screens during a workout. Each of these can display a maximum amount of 8 data fields from the available 44.
The Primary Screen is where I start and finish a workout, but usually I do not use it during a ride. It gives the most important information about the current session, as the Time, Speed, Distance, Average Speed, Cadence and Heart Rate are on the display here.
The Secondary Screen is my main screen, I use it for 99% of the time during my workouts. It gives me important feedback about the intensity of my ride, as the Heart Rate Graph, the Heart Rate, Heart Rate Zone, Cadence and Speed values are displayed here. This way I can monitor if the power I put into pedaling is on the level which I need (to reach the goals I have set for the ride). The Heart Rate and the Cadence values also help in the selection of the best gear-ratio for the given circumstances. And though it uses a lot of screen-space, I love the Heart Rate Graph, as it gives an immediate graphical feedback on every slight change in the intensity of my ride.
The Third Screen – in my case – is set up for rides in the mountains – so I do not use it at all here in Belgium, but as soon as I can go for a cycling holiday, it will be the main screen for the days there. Then I can track the current Elevation (to see that there is still a lot to go), the Grade (steepness of the climb), my Speed, Distance, the air Temperature (for a meteorology-addict, this is a must), the Total Ascent, and the usual Cadence and Heart Rate values.
I think that having such a tool helps a lot during the rides, and being able to track, display and compare all the values from all the rides gives a lot of motivation too :) Gadgets are my religion.
First, read a small overview by a foreigner (OK, not just a foreigner, but the most famous non-competitive cyclist) on Copenhagenize.com, then have a look at the newest TV-spot :)
“The workdays are long and the weekend is short? Make a turn! Bike every day, bike to work too!”
Other things: I totally overcompensated when I switched back from night-time workdays to a normal rhythm, because now I am falling asleep at 8 on the evening, and waking up between 4 and 5 on the morning… I hope I will manage to correct this minor problem in the coming days. And just for the record, I have tasted another new beer, the Hoegaarden Grand Cru.
Of course I am not observing the two inner planets with Mercator, but I just wanted to show how beautiful they are on the evening sky. The picture is from the 29th of March, and Mercury is climbing even higher above the horizon these days, so I think there is a good chance that it may be visible from Leuven too! On the 4th of April, they will be only 3 degrees apart, and still more than 10° high 30 minutes after sunset – at that time it should be easy to catch them with the naked eye.
Yesterday I had a quite bad headache during the night – probably because I could not sleep more than 5 hours on the day before – that’s the reason for not posting anything. (Of course all my painkiller pills were down in the Residencia…) Anyway, the weather was almost as good as on the 10th night (which was the best night of the observing run, despite the full Moon), so I had to concentrate to get as many measurements as possible. I have to admit, that this was much harder then on the previous nights. But I managed. And finally I could sleep 8 hours afterwards!
Now I am a bit sick and tired of working on my pictures (tons of raw images, and I like playing with Photoshop, but now my eyes hurt), so I need to stop doing it for some days… I will upload those which are already processed to flickr as soon as possible. But you won’t find this panorama there, because the stacking of the original images is not perfect (though it is barely noticeable on this small version), and I just don’t like the fact that it is not perfect :( And to make something like this, I would need the 303 SPH VR head for my Manfrotto tripod – but I am not going to spend another 500 Euros on photo equipment soon…
This is my last night at the telescope and I had 100% clear weather (except one hour, when I could not measure anything because of thick cirrus clouds), so I am quite happy. But usually it is clear when I am at the telescope, so I am not surprised at all :) Of course this may be only a strange coincidence, or – which is much more likely to be the case – the result of my weather-influencing superpowers…
Public outreach is important for Astronomy on every level. Tell someone the word astronomy, and people will think of the colorful images from the Hubble Space Telescope, or pictures of the magnificent view of the Milky Way above distant shiny – white or silver – domes on deserted mountaintops (above the cloud level of course), or images of huge mirrors in metallic frames inside a building, which probably has a truly sci-fi look with lights all around, strange windows, and enormous scales. (Or they think of an old man with a strange hat and long white beard, sitting at a desk covered with hand-drawn maps of the sky in front of a small, copper telescope… But that is a different story.) So we need the fancy images, because they may not represent the scientific content of our research, nor they tell interesting details about the high level of engineering behind the magnificent constructions we work with, but they do represent the beauty of our Universe, and they make people curious about the secrets outside of this World. I am sure this picture would raise numerous questions in the mind of an outsider:
This is the 1.2 meter Mercator Telescope on La Palma (the bright setting “star” is Venus). And there is a whole story about how I took the picture. I had to make several calculations, to have the perfect result. First of all, the basic idea is to have a long exposure, turn on the light inside, then rotate the dome 180° to “sample” the interior through the rotating slit. The dome has a rotation speed of 3°/second, this means that you need 60 seconds for the whole half circle, but you should take a bit more, because it is better to start at a point, where the slit is not yet visible, and end when it is not visible any more. So rotating 200° is perfectly enough. This gives a safe exposure time of 75 seconds (you need those extra seconds for safety reasons – I will tell you why). Now, you do not want to overexpose anything in your image, so you have to take care of two things. The sky should not be too bright (which places you somewhere around the time of the nautical twilight – which is perfect, because you can take the picture between the calibrations and the real observations, literally in the twilight zone), and the inside of the dome has to be also well exposed. Basically the latter will set your ISO or f value (as the exposure time is already set by the rotation speed of the dome). Because from the width of the slit you can easily find out, that light will be visible from the same inside point for 12 seconds (it takes this amount of time for the slit to rotate its own width), so you have to set your ISO or f to a value, using which a 12 second exposure of the non-moving dome is not yet overexposed (simulating the passage of the slit on the moving dome). Then you will have to take the picture, when these given settings are not overexposing the sky anymore (as we are heading to the night and the light level gets lower). So when you reach this point during the twilight, there comes the difficult part. Because you are alone, the camera is outside, the dome-control is inside and you have to push two buttons at the same time. So, what can you do? You need to use a timer, set your camera to start the exposure in 1 minute, check the time on your watch, start the timer, run in, and when the 60 seconds are elapsed, start to rotate the dome. When you are done with the needed 200°, the exposure will just automatically (thanks to your calculations) finish outside :) And you have the safety extra seconds, so a couple of seconds plus or minus wont ruin your final picture. Three important things: 1) you need to do this when the Moon is up in the sky if you want to see more than the inside and the bright horizon, because the illumination of the building and the scenery around is the effect of the moonlight. 2) Set the telescope into a position close to vertical, so if – by any chance – something happens to fall down during rotation from the side of the slit, it will not fall into the tube. (Upright position is safe, because there is no moving part above the tube at this setting, even if the tracking of the dome – meaning that the position of the slit follows the pointing of the telescope – is switched off, and you rotate the dome around without co-moving the telescope with it.) 3) No precious observing time is lost, because at the time of the nautical twilight, the sky is still too bright to start measurements. To close this detailed manual, I show you the rising Milky Way on the morning of yesterday. No calculations were carried out for this image :)
