Wednesday, 25 January 2012

Save our skies

BBCStargazing Live promoted the need for dark skies in the UK. Over 4 million people watched the show every night on BBC2, and hundreds of thousands around the UK attended live events.

Astronomy Magazine's article with the IDA stated

"Without question, lights help us feel secure. Whether in our houses, our cars, or on our pavements (UK), we bask in the protective glow of lights. The IDA does not seek to eliminate such useful and necessary forms of lighting. Instead, it just hopes to modify the current excessive lighting practices. Following through with such efforts can conserve energy, reduce harmful glare on the road, and of course, allow for a purer view of the night sky"

If you value the skies, and want to make it possible for future generations to also see amazing sights, please put this in your timeline and encourage every friend you have in the UK to sign it...Sensible lighting will save millions for the economy too.. It takes about a minute to sign... thank you

Monday, 23 January 2012

Comets over Christmas - La Palma and Faulkes Combine

Our "amateur" astronomy research team working on comet and asteroid related projects imaged a range of objects using the 2-metre telescopes of Faulkes (F65 & E10 MPC codes) and the La Palma-Liverpool (J13 MPC code).

We're currently working with support astronomers at La Palma working out methodologies for taking more detailed observations of the compositions of the comets ahead of a long term project supporting the Rosetta spacecraft mission, investigating dust and gas emissions from the comets.

Here's our team blog

Friday, 20 January 2012

How I take some space piccies - a step by step guide

Okay, this is the most common thing I get asked..."how in the h**l do you take images like that?"

Let's just say that I've been in to this for years, and have read/studied and learnt many tricks from some truly great people along the way. I can recommend some cracking books like Ron Wodaski's "New CCD Astronomy" which was like a mini bible for this topic, and Steve Richards excellent "Making every Photon Count" which I reviewed for UK magazine Astronomy Now when working as their equipment consultant.

So... from the start to the end, in a simplified manner, here goes

1: Check the skies... if the night is nice and clear, lots of stars, no or v little Moon light, and little or no clouds, it's time to get the equipment pointing up. I am lucky to have an observatory which was built by a local firm based in Marlborough, Wiltshire. It's a run off roof 8ft x 6ft shed, with CCD security/alarms and a direct underground link to the house, which means I now (as is the case with 99% of professional observatories) do all my work from indoors operating it remotely. In the observatory are netbook sized laptops which connect to the telescope mount and cameras, they are ethernet linked to the house via a powerline ethernet link, and that's about the size of that

2; Equipment. 80% of my night time imaging is done on a 4" refracting telescope, not a monster big Hubble like thing, a small, but very good optically TMB105 telescope. It is connected to a focal reducer, which gives it an F4.9 focal ratio (wider field and faster for imaging faint objects), which is then connected to a cooled Atik 4000 camera, usually running at around -35 degrees (the cooling keeps the amount of noise in the camera down to almost zero). Noise is a key factor in astro imaging, and most DSLR's cope well with it these days, but the professional cooled CCD still beats pretty much all. Dual stage cooling, as in the Atik (triple in the 4000 with a water cooling option) really does kill almost all the noise.

That sits alongside a skywatcher ST102 (102mm) refracting telescope which has a Meade DSI-C CCD camera on it, which in turn acts as a guide camera. I use that as it's very sensitive compared to many of the other CMOS type guide cameras, and up to now has never ever failed to find a guide star with a 1s exposure.

A guide camera is critical for deep sky imaging, as it basically locks on to a star in the field of view where you're imaging, and sends minute corrections to the telescope mount (which, unless you spend about £10K on a mount, will need it) to ensure that the scope locks on to your target. Both scopes have dew heaters wrapped around the top near to the main lens to get rid of any dew (Kendrik dew heater with 4 channels, the other two work on the other scopes/cameras). I use a GPUSB guide port interface, which connects to my EQ6 telescope mount, and then via USB to the computer. The cameras also connect via USB to the computer. So in effect, you need a laptop with at least 3-4 USB ports or a USB hub, ideally an active one to get it all connected. (in this scenario)

3: So... first things first... Boot up the PC, and then I launch an application called PHD Guide. This is free and brilliant guide camera software written by Craig Stark. I select the Meade DSI and the GPUSB and then select 1-2 seconds exposure time..the camera, which at this point is pointing towards polaris (which is the telescope's "home" position) shows me stars. Next step, I boot up the Atik capture software, which comes free with the Atik cameras.

I set this up to start cooling down the camera (takes about 3 minutes on average) and again cycle to expose on the stars near polaris. I check the filter wheel (Atik EFW which is also connected via USB as it's motorized), and check the focus position on the filters I will be using (they are all parfocal Astronomik filters, but I always check them each night) The filters I typically use are CLS (light pollution, though it's not bad near me at all), H-Alpha, OIII, SII and HBeta. These are almost all narrowband filters, which work really well on nebula and comets (OIII on comets is v good)The SII/HA/OIII combination of filters when mapped to RGB colours is commonly referred to as "The Hubble" palette as it was used famously on the 1995 image of the "Pillars of Creation"

4: Then comes the magic bit...using another bit of free software called EQMOD, and EQASCOM control, I launch a free planetarium application called Cartes Du Ciel. In this I have various star catalogues loaded (also free). The software then gives me the option to "connect to telescope" which I do, and this fires the EQ6 in to life. The planetarium software now shows me that the telescope is pointing at Polaris. I then, after checking with websites like and various star maps I have, will pick a target (maybe a new comet, maybe a galaxy, may be a nebula)..I tend to image nebula in narrowband only when the Moon is up, and galaxies using the CLS filter and NB filters when not. I then click on the target and select "slew to target" on the software. The scope then moves to and locks on to the object I wish to image, with frightening accuracy...seriously, dead centre 99% of the time.. EQMod is free and it basically allows you to "map" alignment points of stars, which I do every few months or so (to refresh it), this is how it is so accurate.. great and free software!

5: Okay, so scope and cameras are now ready, cameras are cooled down, scope pointing at target. Go back in to Atik capture software, and set the binning (making the pixels work together) to 6x6 I select a 3 second ish exposure to verify that the object is in the right position (accuracy is one thing, aesthetic/framing is another!). I may then move the scope a bit, again using the software controls to nudge it.. when happy with positioning, I set up the Atik sequencer control to select the exposure times (anywhere from 30s to 40 minutes...yes, I have done 40 minute single exposures before!!) and leave that..

6: Then, back in to PHD guide software, and exposure time at 1-2 seconds, get a suitable guide star. Click on the PHD button, wait about 1 minute whilst it calibrates the mount, works out which way is which, and after a minute says "guiding", the star locked in cross hairs. I turn on the guide graph to verify how accurate the guides are

7: Now with the guide lock on, I go back to the Atik software, set the binning to 1x1 or 2x2 (both good enough resolution to get nice images) and select a star. Binning is when adjacent pixels on the CCD combine. It reduces the time needed to take the image, but also reduces the resolution, so works best I find on higher resolution cameras. I will fractionally tweak the focus until the star's FWHM (focus assist) reads a value close to or <1 (usually on a good night below around 1.5, but on an exceptional night <1), this means the stars are really tightly in focus. You can use various masks on the front of the scope, I just prefer the FWHM method, it works for me.. 8: Focus on, all looking good... set a test exposure up of say 60s, check it all looks nice at that time, then run the sequencer... leave to stew for however many hours that takes...go inside for cuppa !

9: Now, totally from indoors (it's warm!), remote desktop link in to laptops in observatory using Windows RDP or some VNC client (if using iphone/android phone which I sometimes do) set sound on, (as PHD guide will beep an alarm if it loses a guide star, which usually means a cloud or something got in the way, and that will cack up the image too)

10: When the image sequence run is done, I usually have about 30-60 individual images, around 10-20 for each of the usually 3 filters I will use (depending on the object).. these are all in FITS format

11: Now, load up Maxim DL (expensive software, but superb, really is the best out there).. load up the images in to that, and calibrate them.. This means noise reduction. Prior to imaging, about once a month (usually on a cloudy night) I will create a set of flat field frames (which are basically a white image created by covering the front of the scope in a white t-shirt and shining a diffuse lamp on it) . These show up any dust or other munge on the CCD/filters etc... I also do dark frames (cover the telescope with it's cover/cap and expose the camera for as long as your actual exposure times, so I have darks for 240s, 360s, 600s and 2400s stored). These record just the camera noise at the temperature I run it at.. usually not much, but then using the calibration option in Maxim DL, it removes all trace of dust and noise in all the images I have taken..

12: Next step, stack the images. Using Maxim DL's stacking option, I will then load up all the images into groups (usually called HA/OIII/SII etc) and set the minimum threshold of acceptability in each image (Maxim has an option for this for roundness etc).. Then hit the stack button and get three images which are the sum of all the images taken (I use SD mode in Maxim to sum the images, removing any cosmis ray strikes etc)

13: Now, we have three master images. Save them in FITS format

15: Next I usually run Maxim DL's DDP processing option. This kind of makes the overall image levels better, so, brighter cores in galaxies sit better with the outer arms...that kind of thing. This is well documented online.

15: Next step, I use a process known as deconvolution to tighten up everything more.. the fat tail deconvolution plug in (free) for Maxim DL works well, takes a minute or two to work, but works nicely and you get really tight stars

16: Finally, take the images and load them in to Photoshop (I use CS5, but GIMP or earlier versions will work). I use Noel's actions (google it!) for photoshop to clean up and tweak the images a bit more (usually noise reduction and light pollution removal). Then create a final image by combining the three images as Red, Green and Blue channels. Adjust levels and curves to taste, sometimes use the excellent "Focus Magic" to tighten the focus up a bit more..

And that's it! It's how I roll, but there are a billion different ways around this. The books I have suggested are excellent starters, and also forums like UKAstroImaging and Stargazers Lounge have tons of people doing this all the time, with different equipment, cameras etc...

Stargazing Live - The Future is in our hands

For the past year, BBC each January have hosted a new and exciting event known as Stargazing Live.

Devoting three nights of prime time television to a niche subject like astronomy was possibly a risk, but on the back of Professor Brian Cox's monumental success with his "Wonders" series, one that was clearly going to come off. The BBC assembled a great, dynamic and young team of people, alongside very familiar, yet astronomically linked faces like the intensely funny Dara O'briain to create a show that, coming from the kudos centre that is Jodrell Bank, home to the third largest fully steerable radio telescope on the planet, was almost guaranteed to succeed from the offset.

For the first show I did some work behind the scenes work on some image processing for Dara and the team at Faulkes Telescope, this year, the involvement levels went up quite a notch, as FT were involved not only in UK wide Big Screen events coordinated by Dr Paul Roche and Dr Edward Gomez of LCOGT (who manage the Faulkes scopes) , but also via the BBC TV program Blue Peter. The BBC, aware that the main live shows were going out late for many young people, were intent on taking the Stargazing Live concept to that younger audience.

Last summer, I coordinated a project trying to see if we could detect new asteroids. Our team at CARA (Comet Research group based largely in Italy) have been working with NASA on the EPOXI mission and are continuously imaging, and trying to find new comets, doing comet recovery programs to detect faint comets coming around again, looking for outburst and fragmentation events and tracking comets over long periods to measure dust and gas values, using both amateur sized telescopes and also the twin Faulkes Scopes. More recently we have been given permission to use the La Palma 2 metre Liverpool Telescope via a formal proposal process, which was a nice bridge again between what amateurs and professional observatories do.

The BBC filming lasted a day at the University of Glamorgan and then on to the really wonderful Hannah Blyth's house, Hannah being the Nuffield foundation student I was working with on the asteroid project. Hannah has since been nominated for two exceptional awards for her part in the project, and Faulkes have seen a massive increase in registrations and use, thanks to various TV/Radio and news items we both did. The Blue Peter show aired this week, and reaction has been really nice from friends, family and also my managers at the European Space Agency, who were thrilled that we got a Blue Peter badge (kind of special in the UK, and it gets you in to hundreds of places for free, which has thrilled my 5yo daughter no end)

Two radio interviews and a set of live talks at the birthplace of photography, Lacock in Wiltshire, to an event hosted again by the BBC to 2500 people ended up an amazing week of Stargazing live for me. I had worked also on a big ESA news release, which made the BBC home page courtesy of their fantastic science journalist Jonathan Amos, and had images I had taken shown on the live TV show, and used extensively on the BBC website.

But the best bit by far for me..and the reason I love astronomy so much...was seeing the looks on not only my own daughter's face, but also on the faces of hundreds and hundreds of kids who attended the stargazing live events, kids who had been dragged out in our case in Wiltshire, on a rainy cloudy night to experience the real wonders of the universe, via planetarium displays, robotics demos, rocket launches... etc. You know that scene in "Charlie and the Chocolate Factory" where the kids first enter with their golden tickets... that's the best way to describe it.

If just ONE of those young people goes on to become an astronomer or scientist, then we, as people sharing our passion for space, will have made the world a bit better, and maybe given our planet's future the next Einstein, Feynman or Sagan. The spark and flame in the mind of a young person, once lit...very rarely goes out, if you keep feeding it the oxygen it and space are two things most young people love.. its up to us to encourage that...

And this message goes out to all the academics, many of whom I know relish the notion of passing on to a younger audience their love of space, but, sadly not all... to those, remember this fact...

No matter how far up the academic ladder you reach in astronomy ,at some point,someone inspired you to start to climb...and most likely that was when you were a child.

You may never reach the top, you may never achieve whatever it is you reach for.... but so long as you always remember to help those on the rungs below, you'll always make a difference to someone's life, and that is better than any prize, from a Blue Peter Badge to the Nobel.

To watch the Blue Peter piece on BBC's iplayer (UK only), click here.