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While clouded in and waiting for knee surgery, I started playing with data from the Liverpool Telescope (http://telescope.livjm.ac.uk/). I downloaded all the NSO data on NGC 2841, a very nice flocculent galaxy in Ursa Major, and started processing in PixInsight. While I couldn't get anywhere with the colour of this galaxy, the luminance created from the combined filters revealed structures that I've never seen before in an image of this galaxy.
I combined a colour image of NGC2841 with an inverted superstretch of the combined SDSS-r, Bessell-V, and Bessell-B filters.
Red: 35 frames SDSS-r' Green: 16 frames Bessell-V Blue: 20 frames Bessell-B L image:
integration of all 71 frames, approximately 100 minutes total exposure time. Field size: roughly 10 x 10 arcminutes.
The arrow points at a weak loop, and the circle shows a slight density increase in the weak structure.
By Mark Daniels
Ok so i and my wife have been travelling to the canaries in the winter for a few years. This coming January we are looking at la palma.
I will be taking a small travel scope for the evenings a sw 50 ed and small tripod also some 10x50 binos
I would like some guidance from those who have been before. Things like a nice hotel in a not to built up area where we can walk of an evening drink some wine and look up to the stars.
Also iwould lile to visit the observatory and from what i can gather need to arrange independently so any info on this would be good. Also are the stargazing evenings on offer any good
Any info on must see tours or nice resturants etc are very welcome as this is a holiday so stargazing is only part of the reason to go.
Thinking south or west of island but opento all suggestions ans experiences
A few years ago (already? time flies) @gorann and I hoovered the Liverpool Telescope archives and processed most of the DS data that is in there. https://telescope.livjm.ac.uk/Gallery/
Having not much to do yesterday, I returned for scraps. I found three image files on ngc 891, one red image, one green and one blue image. Each has an exposure time of 90 seconds. I combined the three images into one synthetic L image and processed the data as LRGB. So here it is, 4.5 mintues of professional data
(click on the image for a full size view)
Clearly it pays off to have large pixels and a large mirror on a high mountain top. The telescope is an f/10 RC design with a 2 m mirror and a 4K x 4K pixel camera. Pixelsize is 15 um, but all images are binned 2x2, giving an effective pixelsize of 30 um in a 2 000 x 2 000 array.
The master images had a lot of cosmic rays and hot pixels, so in creating the L master I had to use pixel rejection, which I'd not do normally. I removed much of the cosmic rays and bad pixels in the rgb combined image, before stretching. Here's what the original rgb data looked like.
Still fighting DSS to stack my 46P subs, so made a time-lapse instead.
89 x 1min, taken on 27 Dec with Fuji x-T1 and Samyang 135mm. Size of frame is 2.2 x 1.7deg.
Have a much better quality avi file, but that's 214MB, so need to figure out how to convert it to MP4 in better quality (for this one I used youtube ?)
This August I was lucky enough to go back to La Palma with the family for a couple of weeks. Perhaps more importantly I was able to take my cameras, and this time I hired a telescope over there rather than look at the skies wishing I had my scope with me.
Same as last time we were unlucky with the weather, by La Palma standards, and several nights were lost to very thick Calima - dust laden winds blowing from the Sahara . These clog up the sky and raise the temperature quite drastically. It also severely hampered my ‘schedule’ of timelapses I wanted to get but living in the UK I can expect perhaps one night in two weeks to be clear. I can’t complain at the loss of 4-5 nights out of two weeks! Although it was frustrating to miss the Perseids again - they were on the one night it actually rained!!
La Palma, perhaps surprisingly for one of the best locations for astronomy in the world, is a very cloudy island. When conditions are ‘normal’ it is usual for the inhabited parts of the island at less than 3000 ft to be frequently cloudy at night time. The cloud comes and goes but is often there and can be seen in several of my timelapses. There is an inversion later at approximately 3000ft though above which it is as clear as it’s cloudy below. So, if you can get high enough you can get above the clouds and almost guarantee starry skies. But, the same situations that give those clouds give us cloud waterfalls over the Cumbre Vieja (the ridge of hills linking the north and south of the island) and some amazing fog. I could go back to La Palma just to do timelapses of the fog/cloud!
If you can get high enough it’s truly worth it. Up at altitude the skies are very steady and clear. I could see detail and texture in the Milky Way right through from beneath Scorpius/Sagittarius, right overhead and down into Cassiopeia and Perseus. The Milky Way was visible right down to the horizon and the stars were pinpoint spots of light - no twinkling, not even low on the horizon! There are various spots at the side of the road you can set up on - although be prepared for a number of cars to drive past with their lights full on! I was quite surprised at the number of cars - several of my timelapses show the observatories lit up by cars with their lights on full. Of course, arguably I was part of the problem… but then I was happy to drive around on sidelights (once I’d sorted out turning off the cars internal illumination!)
I met and spoke with a surprising number of people, mostly Spanish and German. But it was frustrating whilst taking a timelapse to have people drive up and take pictures of themselves pointing a torch at the Milky Way, right in my field of view. Some of my timelapses show this despite my best efforts.
I was able to take Tom up with me a couple of times (even Kate came up too one night!). I quite like being on my own at night but at altitude and with the humidity at less than 5% and the walking around often being on rocky broken volcanic surfaces it was good to have company. Of course, Tom being 10 he can see way better than me, something he was happy to point out regularly!
I've put together a timelapse which I’ve called the Road to the Roque. Whether you approach the Roque from the east from Santa Cruz de la Palma or from the north west (Hoya Grande) it’s at the top of a long very switchbacked road. Driving up and down 7-8 times over the two weeks burned out the hire cars brakes - thank goodness for power steering! You can’t get to the top without going up the road - the views along the way were stunning so any timelapse I put together I wanted to include that part of the journey! The car brakes really were burned out. On the last day driving back to the airport they were noisy enough I felt it best to leave the car in second gear for the last 13km (downhill)..
I hired a telescope for about a week out there from an outfit that turned out to be just 10 minutes up the road ( http://athos.org ) A German setup (the guy I spoke to, Jan, spoke perfect English!) which has to be the kind of place I’d happily just move to (just as soon as that lottery win comes in). They have a place with several small houses for accommodation, observing platforms, observatories, plenty of kit and are in a truly dark spot. Absolute Paradise! They kindly gave me a guided tour (they took care I didn’t wake up some of the astronomers that had been up all night) but the place was great. I have started siphoning off money from my joint account… (luckily Kate doesn’t go on SGL!).
I hired an Evolution 6 with Starsense. My rationale was to have something I could carry around easily and for it to be smaller than my main scope at home and something I haven’t used before. It worked out perfectly, the little 6 inch was giving me much better views than my 10” Newt does a home and many an hour was spent looking at Mars, Saturn, Jupiter and Venus and looking at objects in the lower reaches of the Milky Way that we can’t normally see from the UK! The starsense was cool - level, aim north, hit a button… and it just worked!
I could blether on for hours but won’t - here’s a link to the time-lapse I’ve done. Its missing some stuff I wanted to get but some stuff worked better than I’d expected so I can’t complain. A couple of the timelapses were done in strong dusty winds, in one of them I spent an hour hunched over the camera on it’s tripod holding a large black cloth as a shield for me and the camera from virtually gale force winds. Amazingly that one worked well although my shoulders weren’t so happy! Getting lost on the path on the way back down to the car was a bit hairy (the caldera was 20 ft to my right) but a bit of judicious Maps usage on my phone (most of the island provides at least 3G) enabled me to figure out that the all but invisible path I needed was just a few feet back from where I was…
Finally, all else aside, I can’t overstate what having dark skies does. I live in a dark part of Devon and am grateful for that but the skies there were obscenely dark. The little villa we were staying in near Puntagorda on the north west of the island - you could walk literally straight out of the lit kitchen onto a patio and bang, there was the Milky Way, better than we even see it here, visible clearly in completely un dark adapted eyes… five minutes later and it’s enough to make you think… I could work from here you know, no need to go back to the UK….
I’ve started blethering again. Here’s the timelapse, I hope you enjoy it!