Artist's impression of the European Extremely Large Telescope. Credit: ESO
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The world’s largest optical/infrared telescope has been given the initial go-ahead to be built. Called the European Extremely Large Telescope (E-ELT) this long-proposed new ground-based telescope will have a 40-meter main mirror and observe the universe in visible and infrared light, making direct images of exoplanets, perhaps find Earth-sized and even Earth-like worlds, and study the first galaxies that formed after the Big Bang.
“This is an excellent outcome and a great day for ESO. We can now move forward on schedule with this giant project,” said the ESO Director General, Tim de Zeeuw.
At a meeting in Garching, France this week, the ESO (European Southern Observatory) Council approved the E-ELT program, with 6 out of 10 countries giving firm approval and four gave “ad referendum” approval, meaning that they needed an official green light from their governments. With that approval, officials are hopeful the E-ELT could start operations by the early 2020’s.
The new super-large eye on the sky will be built at Cerro Armazones in northern Chile, close to ESO’s Paranal Observatory.
The cost is expected to be $1.35 billion USD (1.083-billion-euro)
“World-leading projects of this kind inspire us all and are hugely effective in bringing young people into careers in science and technology,” said David Southwood, president of the Royal Astronomical Society.
This type of telescope has been on the priority list for astronomy by scientists around the world.
The E-ELT will gather 100 million times more light than the human eye, eight million times more than Galileo’s telescope which saw the four biggest moons of Jupiter four centuries ago, and 26 times more than a single VLT telescope.
“The E-ELT will tackle the biggest scientific challenges of our time, and aim for a number of notable firsts, including tracking down Earth-like planets around other stars in the ‘habitable zones’ where life could exist — one of the Holy Grails of modern observational astronomy,” the ESO said.
ESO said that early contracts for the project have already been placed. Shortly before the Council meeting, a contract was signed to begin a detailed design study for the very challenging M4 adaptive mirror of the telescope. This is one of the longest lead-time items in the whole E-ELT program, and an early start was essential.
Detailed design work for the route of the road to the summit of Cerro Armazones, where the E-ELT will be sited, is also in progress and some of the civil works are expected to begin this year. These include preparation of the access road to the summit of Cerro Armazones as well as the leveling of the summit itself.
Could two unused satellites given to NASA help resurrect the proposed WFIRST mission? Credit: NASA
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NASA will be getting two unused space surveillance satellites from the US’s National Reconnaissance Office, which could possibly be used to search for dark energy. In articles in the Washington Post and the New York Times, NASA and NRO officials revealed the two unused and not-fully-built satellites are available for NASA to use as they see fit. While the satellites don’t have astronomical instruments and are still in a warehouse, they do have 2.4-meter (7.9 feet) mirrors, just like Hubble, with a wider field of view and a maneuverable secondary mirror that makes it possible to obtain better-focused images.
“This is a total game changer,” said David N. Spergel of Princeton, quoted in the New York Times, who is co-chairman of a committee on astronomy and astrophysics for the National Academy of Sciences.
Reportedly, the NRO contacted NASA in 2011 about the two spy satellites. Since taking over as head of the NASA Science Directorate early this year, former Hubble repairman John Grunsfeld has been working with scientists and other NASA officials to quietly study the possibility of using the two satellites as “repurposed telescopes.”
Originally designed to look at Earth for surveillance, the two telescopes could be turned to look at the heavens instead, as the National Reconnaissance Office said they no longer needed them for spy missions. Why two such spy telescopes were under construction and then scrapped is not clear.
Described as not fully built and some parts being in “bits and pieces,” NASA will have to decide on how they should be used, build additional instruments, launch them, and support the operations.
Reportedly, Grunsfeld and his secret team have come up with a plan to turn one of the telescopes to investigate the mysterious dark energy that is speeding up the expansion of the universe.
NASA officials stressed that they do not have a program or a budget to launch even one telescope at the moment, and that at the very earliest, under favorable budgets, it would be 2020 before even one of the two gifted telescopes could be ready for a mission.
The Washington Post asked Grunsfeld whether anyone at NASA was popping champagne, and he answered, “We never pop champagne here; our budgets are too tight.”
In the latest decadal survey the astronomical community had suggested a dark energy telescope as its top priority in astronomy and astrophysics, but the lack of funding – along with huge cost overruns by the James Webb Space Telescope — made it seem like such a telescope would be an impossibility.
The two telescopes could possibly be used for the proposed WFIRST project, which seemingly was not going anywhere with the latest budget proposal or as a ‘scout’ for the JWST.
“It would be a great discovery telescope for where Webb should look in addition to doing the work on dark energy,” Spergel said in the Washington Post.
Astronomers will be discussing the possibilities at a meeting at the National Academy of Sciences held on today in Washington, D.C. and how they could turn the two gifted telescopes into official missions.
The Royal Observatory Greenwich is giving free presentations of "Measuring the Universe: from the Transit of Venus to the Edge of the Cosmos" from now until September 1.
Measuring distance doesn’t sound like a very challenging thing to do — just pick your standard unit of choice and corresponding tool calibrated to it, and see how the numbers add up. Use a meter stick, a tape measure, or perhaps take a drive, and you can get a fairly accurate answer. But in astronomy, where the distances are vast and there’s no way to take measurements in person, how do scientists know how far this is from that and what’s going where?
Luckily there are ways to figure such things out, and the methods that astronomers use are surprisingly familiar to things we experience every day.
[/caption]The video above is shared by the Royal Observatory Greenwich and shows how geometry, physics and things called “standard candles” (brilliant!) allow scientists to measure distances on cosmic scales.
Just in time for the upcoming transit of Venus, an event which also allows for some important measurements to be made of distances in our solar system, the video is part of a series of free presentations the Observatory is currently giving regarding our place in the Universe and how astronomers over the centuries have measured how oh-so-far it really is from here to there.
Video credits: Design and direction: Richard Hogg Animation: Robert Milne, Ross Philips, Kwok Fung Lam Music and sound effects: George Demure Narration and Astro-smarts: Dr. Olivia Johnson Producer: Henry Holland
Image of the Thor's Helmet nebula (NGC 2359) Credit: R. Barrena (IAC) and D. López
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Going to see the new Avengers movie this weekend, either for the first or fortieth time? You may not see much of Thor’s helmet in the film (as he opts for more of a “Point Break” look) but astronomers using the Isaac Newton Group of telescopes on the Canary Islands have succeeded in spotting it… in this super image of the Thor’s Helmet nebula!
Named for its similarity to the famous horned Viking headgear (seen horizontally), the Thor’s Helmet nebula is a Wolf-Rayet structure created by stellar winds from the star seen near the center blowing the gas of the bluish “helmet” outwards into space via pre-supernova emissions.
The colors of the image above, acquired with the ING’s Isaac Newton Telescope, correspond to light emitted in hydrogen alpha, doubly-ionised oxygen and single-ionised sulfur wavelengths.
Super-sized for the thunder god himself, Thor’s Helmet measures at about 30 light-years across. It’s located in the constellation Canis Major, approximately 15,000 light-years from Earth. (You’d think Thor would have left his favorite accessory in a more convenient location… I suspect Loki may be behind this.)
Astronomers, assemble!
Read more about this and see other images from the ING telescopes here.
The Isaac Newton Group of Telescopes (ING) is owned by the Science and Technology Facilities Council (STFC) of the United Kingdom, and it is operated jointly with the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO) of the Netherlands and the Instituto de Astrofísica de Canarias (IAC) of Spain. The telescopes are located in the Spanish Observatorio del Roque de los Muchachos on La Palma, Canary Islands, which is operated by the Instituto de Astrofísica de Canarias (IAC).
This image of the region surrounding the reflection nebula Messier 78, just to the north of Orion’s belt, shows clouds of cosmic dust threaded through the nebula like a string of pearls. Credit: ESO/APEX (MPIfR/ESO/OSO)/T. Stanke et al./Igor Chekalin/Digitized Sky Survey 2
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On Earth, dust can be pretty mundane. But in space, dust can be beautiful, especially when the dust reflects starlight – and even more so when we have the chance to see the reflections in different wavelengths. Here in NGC 2068, also called Messier 78, this dazzling submillimetre-wavelength view from the Atacama Pathfinder Experiment (APEX) telescope Dust shows the glow of interstellar dust grains, pointing the way to where new stars are being formed.
This reflection nebula lies just to the north of Orion’s Belt. When seen in visible light glimmers in a pale blue glow of starlight, but much of the light is blocked by the dust. In this image, the APEX observations are overlaid on the visible-light image in orange. APEX’s view reveals the gentle glow of dense cold clumps of dust, some of which are even colder than -250 C.
A visible light image from ESO of the reflection nebula Messier 78. Credit: ESO and Igor Chekalin
Compare the new image with this earlier, visible light image of M78.
One filament seen by APEX appears in visible light as a dark lane of dust cutting across Messier 78. This tells us that the dense dust lies in front of the reflection nebula, blocking its bluish light. Another prominent region of glowing dust seen by APEX overlaps with the visible light from Messier 78 at its lower edge. The lack of a corresponding dark dust lane in the visible light image tells us that this dense region of dust must lie behind the reflection nebula.
Observations of the gas in these clouds reveal gas flowing at high velocity out of some of the dense clumps. These outflows are ejected from young stars while the star is still forming from the surrounding cloud. Their presence is therefore evidence that these clumps are actively forming stars.
At the top of the image is another reflection nebula, NGC 2071. While the lower regions in this image contain only low-mass young stars, NGC 2071 contains a more massive young star with an estimated mass five times that of the Sun, located in the brightest peak seen in the APEX observations.
This chart shows the location of Messier 78 in the famous constellation of Orion (The Hunter). This map shows most of the stars visible to the unaided eye under good conditions, and Messier 78 itself is highlighted with a red circle on the image. This reflection nebula is quite bright and can be seen well in moderate-sized amateur telescopes. Credit: ESO, IAU and Sky & Telescope
The side of the SOFIA aircraft shows it's joint roots, a collaboration between NASA and German Scientists. Credit: Nick Howes
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One of the most remarkable observatories in the world does its work not on a mountaintop, not in space, but 45,000 feet high on a Boeing 747. Nick Howes took a look around this unique airliner as it made its first landing in Europe.
SOFIA (Stratospheric Observatory for Infrared Astronomy) came from an idea first mooted in the mid-1980s. Imagine, said scientists, using a Boeing 747 to carry a large telescope into the stratosphere where absorption of infrared light by atmospheric water molecules is dramatically reduced, even in comparison with the highest ground-based observatories. By 1996 that idea had taken a step closer to reality when the SOFIA project was formally agreed between NASA (who fund 80 percent of the cost of the 330 million dollar mission, an amount comparable to a single modest space mission) and the German Aerospace Centre (DLR, who fund the other 20 percent). Research and development began in earnest using a highly modified Boeing 747SP named the ‘Clipper Lindburgh’ after the famous American pilot, and where the ‘SP’ stands for ‘Special Performance’.
Maiden test flights were flown in 2007, with SOFIA operating out of NASA’s Dryden Flight Research Center at Edwards Airforce Base in the Rogers Dry Lake in California – a nice, dry location that helps with the instrumentation and aircraft operationally.
This scale model shows the telescope position and how the aircraft design works around it. Credit: Nick Howes.
As the plane paid a visit to the European Space Agency’s astronaut training centre in Cologne, Germany, I was given a rare opportunity to look around this magnificent aircraft as part of a European Space ‘Tweetup’ (a Twitter meeting). What was immediately noticeable was the plane’s shorter length to the ones you usually fly on, which enables the aircraft to stay in the air for longer, a crucial aspect for its most important passenger, the 2.7-metre SOFIA telescope. Its Hubble Space Telescope-sized primary mirror is aluminium coated and bounces light to a 0.4-metre secondary, all in an open cage framework that literally pokes out of the side of the aircraft.
As we have seen, the rationale for placing a multi-tonne telescope on an aircraft is that by doing so it is possible to escape most of the absorption effects of our atmosphere. Observations in infrared are largely impossible for ground-based instruments at or near sea-level and only partially possibly even on high mountaintops. Water vapour in our troposphere (the lower layer of the atmosphere) absorbs so much of the infrared light that traditionally the only way to beat this was to send up a spacecraft. SOFIA can fill a niche by doing nearly the same job but at far less risk and with a far longer life-span. The aircraft has sophisticated infrared monitoring cameras to check its own output,and water vapour monitoring to measure what little absorption is occurring.
The Sofia Telescope resides behind the multi tonne frame and control mechanism. Credit: Nick Howes.
The 2.7-metre mirror (although actually only 2.5-metres is really used in practice,) uses a glass ceramic composite that is highly thermally tolerant, which is vital given the harsh conditions that the aircraft puts the isolated telescope through. If one imagines the difficulty amateur astronomers have some nights with telescope stability in blustery conditions, spare a thought for SOFIA, whose huge f/19.9 Cassegrain reflecting telescope has to deal with an open door to the
800 kilometres per hour (500 miles per hour) winds .Nominally some operations will occur at 39,000 feet (approximately 11,880 metres) rather than the possible ceiling of 45,000 feet (13,700 metres), because while the higher altitude provides slightly better conditions in terms of lack of absorption (still above 99 percent of the water vapour that causes most of the problems), the extra fuel needed means that observation times are reduced significantly, making the 39,000
feet altitude operationally better in some instances to collect more data. The aircraft uses a cleverly designed air intake system to funnel and channel the airflow and turbulence away from the open telescope window, and speaking to the pilots and scientists, they all agreed that there was no effect caused by any output from the aircraft engines as well.
Staying cool
The cameras and electronics on all infrared observatories have to be maintained at very low temperatures to avoid thermal noise from them spilling into the image, but SOFIA has an ace up its sleeve. Unlike a space mission (with the exception of the servicing missions to the Hubble Space Telescope that each cost $1.5 billion including the price of launching a space shuttle), SOFIA has the advantage of being able to replace or repair instruments or replenish its coolant, allowing an estimated life-span of at least 20 years, far longer than any space-based infrared mission that runs out of coolant after a few years.
Meanwhile the telescope and its cradle are a feat of engineering. The telescope is pretty much fixed in azimuth, with only a three-degree play to compensate for the aircraft, but it doesn’t need to move in that direction as the aircraft, piloted by some of NASA’s finest, performs that duty for it. It can work between a 20–60 degree altitude range during science operations. It’s all been engineered to tolerances that make the jaw drop. The bearing sphere, for example, is polished to an accuracy of less than ten microns, and the laser gyros provide angular increments of 0.0008 arcseconds. Isolated from the main aircraft by a series of pressurised rubber bumpers, which are altitude compensated, the telescope is almost completely free from the main bulk of the 747, which houses the computers and racks that not only operate the telescope but provide the base station for any observational scientists flying with the plane.
PI in the Sky
The science principle investigators get to sit in relative comfort close to the telescope. Credit: Nick Howes.
The Principle Investigator station is located around the mid-point of the aircraft, several metres from the telescope but enclosed within the plane (exposed to the air at 45,000 feet, the crew and scientists would otherwise be instantly killed). Here, for ten or more hours at a time, scientists can gather data once the door opens and the telescope is pointing at the target of choice, with the pilots following a precise flight path to maintain both the instrument pointing accuracy and also to best avoid the possibility of turbulence. Whilst ground-based telescopes can respond quickly to events such as a new supernova, SOFIA is more regimented in its science operations and, with proposal cycles over six months to a year, one has to plan quite accurately how best to observe an object.
Forecasting the future
Science operations started in 2010 with FORCAST (Faint Object Infrared Camera for Sofia Telescope) and continued into 2011 with the GREAT (German Receiver for Astronomy at Teraherz Frequencies) instrument. FORCAST is a mid/far infrared instrument working with two cameras between at five and forty microns (in tandem they can work between 10–25 microns) with a 3.2 arcminute field-of-view. It saw first light on Jupiter and the galaxy Messier 82, but will be working on imaging the galactic centre, star formation in spiral and active galaxies and also looking at molecular clouds, one of its primary science goals enabling scientists to accurately determine dust temperatures and more detail on the morphology of star forming regions down to less than three-arcsecond resolution (depending on the wavelength the instrument works at). Alongside this, FORCAST is also able to perform grism (i.e. a grating prism) spectroscopy, to get more detailed information on the composition of objects under view. There is no adaptive optics system, but it doesn’t need one for the types of operations it’s doing.
FORCAST and GREAT are just two of the ‘basic’ science operation instruments, which also include Echelle spectrographs, far infrared spectrometers and high resolution wideband cameras, but already the science team are working on new instruments for the next phase of operations. Instrumentation switch over, whilst complex, is relatively quick (comparable to the time it takes to switch instruments on larger ground observatories), and can be achieved in readiness for observations, which the plane aims to do up to 160 times per year. And whilst there were no firm plans to build a sister ship for SOFIA, there have been discussions among scientists to put a larger telescope on an Airbus A380.
A model of the telescope shows its unique control and movement mechanism as well as the optical tube assembly. Credit: Nick Howes.
Sky Outreach
With a planned science ambassador programme involving teachers flying on the aircraft to do research, SOFIA’s public profile is going to grow. The science output and possibilities from instruments that are constantly evolving, serviceable and improvable every time it lands is immeasurable in comparison to space missions. Journalists had only recently been afforded the opportunity to visit this remarkable aircraft, and it was a privilege and honour to be one of the first people to see it up close. To that end I wish to thank ESA and NASA for the invitation and chance to see something so unique.
The 10-meter South Pole Telescope in Antarctica at the Amundsen-Scott Station. (Daniel Luong-Van, National Science Foundation)
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Located at the southermost point on Earth, the 280-ton, 10-meter-wide South Pole Telescope has helped astronomers unravel the nature of dark energy and zero in on the actual mass of neutrinos — elusive subatomic particles that pervade the Universe and, until very recently, were thought to be entirely without measureable mass.
The NSF-funded South Pole Telescope (SPT) is specifically designed to study the secrets of dark energy, the force that purportedly drives the incessant (and apparently still accelerating) expansion of the Universe. Its millimeter-wave observation abilities allow scientists to study the Cosmic Microwave Background (CMB) which pervades the night sky with the 14-billion-year-old echo of the Big Bang.
Overlaid upon the imprint of the CMB are the silhouettes of distant galaxy clusters — some of the most massive structures to form within the Universe. By locating these clusters and mapping their movements with the SPT, researchers can see how dark energy — and neutrinos — interact with them.
“Neutrinos are amongst the most abundant particles in the universe,” said Bradford Benson, an experimental cosmologist at the University of Chicago’s Kavli Institute for Cosmological Physics. “About one trillion neutrinos pass through us each second, though you would hardly notice them because they rarely interact with ‘normal’ matter.”
If neutrinos were particularly massive, they would have an effect on the large-scale galaxy clusters observed with the SPT. If they had no mass, there would be no effect.
The SPT collaboration team’s results, however, fall somewhere in between.
Even though only 100 of the 500 clusters identified so far have been surveyed, the team has been able to place a reasonably reliable preliminary upper limit on the mass of neutrinos — again, particles that had once been assumed to have no mass.
Previous tests have also assigned a lower limit to the mass of neutrinos, thus narrowing the anticipated mass of the subatomic particles to between 0.05 – 0.28 eV (electron volts). Once the SPT survey is completed, the team expects to have an even more confident result of the particles’ masses.
“With the full SPT data set we will be able to place extremely tight constraints on dark energy and possibly determine the mass of the neutrinos,” said Benson.
“We should be very close to the level of accuracy needed to detect the neutrino masses,” he noted later in an email to Universe Today.
The South Pole Telescope's unique position allows it to watch the night sky for months on end. (NSF)
Such precise measurements would not have been possible without the South Pole Telescope, which has the ability due to its unique location to observe a dark sky for very long periods of time. Antarctica also offers SPT a stable atmosphere, as well as very low levels of water vapor that might otherwise absorb faint millimeter-wavelength signals.
“The South Pole Telescope has proven to be a crown jewel of astrophysical research carried out by NSF in the Antarctic,” said Vladimir Papitashvili, Antarctic Astrophysics and Geospace Sciences program director at NSF’s Office of Polar Programs. “It has produced about two dozen peer-reviewed science publications since the telescope received its ‘first light’ on Feb. 17, 2007. SPT is a very focused, well-managed and amazing project.”
The team’s findings were presented by Bradford Benson at the American Physical Society meeting in Atlanta on April 1.
Cracks in the secondary mirror on the Blanco telescope in Chile after an accident on February 20, 2012. Credit: Cerro Tololo Inter-American Observatory
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An accident at the Blanco 4m telescope at Chile’s Cerro Tololo Inter-American Observatory has severely damaged a secondary mirror. The telescope is currently shut down for installation of the highly anticipated Dark Energy Survey Camera, and on February 20, 2012, the telescope’s f/8 secondary mirror was dropped during testing, resulting in fractures in the glass in the center of the mirror. Officials at the telescope said they are analyzing the extent of the damage to the mirror, and whether it extends beyond the visible cracks on the surface. They are also reviewing how the accident might affect the installation of the “DECam.”
Two staff members were injured during the incident, but are expected to fully recover. According to a post on the CTIO website, the f/8 had been removed for the installation of the DECam, and the f/8 was on the dome floor to test the focus mechanism. “The mirror and its back end assembly were being transferred to a handling cart to enable the tests. Unfortunately, the mirror was improperly installed on the cart and when the mirror was being rotated on the cart, the entire cart/mirror assembly toppled over injuring two of our technical staff,” said the report.
The mirror itself impacted the dome floor, causing the fractures, pictured above.
At this time, officials say it is not clear if the mirror is repairable or not and are reviewing what needs to be done to stabilize the cracks in the mirror. The accident is being investigated and initially, officials said they didn’t expect the incident delay the installation and commissioning of Dark Energy Camera as the f/8 is not required for the installation or operation of the Dark Energy Camera system. However, a later update said the DECam installation schedule was being modified to allow for the absence of the f/8 mirror.
The Dark Energy Camera will map 300 million galaxies with an extremely red sensitive 500 Megapixel camera, with a 1 meter diameter, 2.2 degree field of view prime focus corrector, and a data acquisition system fast enough to take images in 17 seconds.
The CTIO website said they would be providing future updates on the status of the mirror and the DECam installation.
The Faulkes Telescope. Credit: Faulkes Telescope/LCOGT
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Using and getting the most out of robotic astronomy
Whilst nothing in the field of amateur astronomy beats the feeling of being outside looking up at the stars, the inclement weather many of us have to face at various times of year, combined with the task of setting up and then packing away equipment on a nightly basis, can be a drag. Those of us fortunate enough to have observatories don’t face that latter issue, but still face the weather and usually the limits of our own equipment and skies.
Another option to consider is using a robotic telescope. From the comfort of your home you can make incredible observations, take outstanding astrophotos, and even make key contributions to science!
The main elements which make robotic telescopes appealing to many amateur astronomers are based around 3 factors. The first is that usually, the equipment being offered is generally vastly superior to that which the amateur has in their home observatory. Many of the robotic commercial telescope systems, have large format mono CCD cameras, connected to high precision computer controlled mounts, with superb optics on top, typically these setups start in the $20-$30,000 price bracket and can run up in to the millions of dollars.
A look at the Faulkes Telescope South inside. Credit: Faulkes Telescope/LCOGT
Combined with usually well defined and fluid workflow processes which guide even a novice user through the use of the scope and then acquisition of images, automatically handling such things as dark and flat fields, makes it a much easier learning curve for many as well, with many of the scopes specifically geared for early grade school students.
Screenshot of the Faulkes Telescope realtime interface. Credit: Faulkes Telescope/LCOGT
The second factor is geographic location. Many of the robotic sites are located in places where average rainfall is a lot lower than say somewhere like the UK or North Eastern United States for example, with places like New Mexico and Chile in particular offering almost completely clear dry skies year round. Robotic scopes tend to see more sky than most amateur setups, and as they are being controlled over the Internet, you yourself don’t even have to get cold outside in the depths of winter. The beauty of the geographic location aspect is that in some cases, you can do your astronomy during the daytime, as the scopes may be on the other side of the world.
iTelescope systems are located all over the globe. Credit: iTelescope project
The third is ease of use, as it’s nothing more than a reasonably decent laptop, and solid broadband connection that’s required. The only thing you need worry about is your internet connection dropping, not your equipment failing to work. With scopes like the Faulkes or Liverpool Telescopes, ones I use a lot, they can be controlled from something as modest as a netbook or even an Android/iPad/iPhone, easily. The issues with CPU horsepower usually comes down to the image processing after you have taken your pictures.
Software applications like the brilliant Maxim DL by Diffraction Limited which is commonly used for image post processing in amateur and even professional astronomy, handles the FITS file data which robotic scopes will deliver. This is commonly the format images are saved in with professional observatories, and the same applies with many home amateur setups and robotic telescopes. This software requires a reasonably fast PC to work efficiently, as does the other stalwart of the imaging community, Adobe Photoshop. There are some superb and free applications which can be used instead of these two bastions of the imaging fraternity, like the excellent Deep Sky stacker, and IRIS, along with the interestingly named “GIMP” which is variant on the Photoshop theme, but free to use.
Some people may say just handling image data or a telescope over the internet detracts from real astronomy, but it’s how professional astronomers work day in day out, usually just doing data reduction from telescopes located on the other side of the world. Professionals can wait years to get telescope time, and even then rather than actually being a part of the imaging process, will submit imaging runs to observatories, and wait for the data to roll in. (If anyone wants to argue this fact…just say “Try doing eyepiece astronomy with the Hubble”)
The process of using and imaging with a robotic telescope still requires a level of skill and dedication to guarantee a good night of observing, be it for pretty pictures or real science or both.
Location Location Location
The location for a robotic telescope is critical as if you want to image some of the wonders of the Southern Hemisphere, which those of us in the UK or North America will never see from home, then you’ll need to pick a suitably located scope. Time of day is also important for access, unless the scope system allows an offline queue management approach, whereby you schedule it to do your observations for you and just wait for the results. Some telescopes utilise a real time interface, where you literally control the scope live from your computer, typically through a web browser interface. So depending on where in the world it is, you may be in work, or it may be at a very unhealthy hour in the night before you can access your telescope, it’s worth considering this when you decide which robotic system you wish to be a part of.
Telescopes like the twin Faulkes 2-metre scopes, which are based on the Hawaiian island of Maui, atop a mountain, and Siding Spring, Australia, next to the world famous Anglo Australian Observatory, operate during usual school hours in the UK, which means night time in the locations where the scopes live. This is perfect for children in western Europe who wish to use research grade professional technology from the classroom, though the Faulkes scopes are also used by schools and researchers in Hawaii.
The type of scope/camera you choose to use, will ultimately also determine what it is you image. Some robotic scopes are configured with wide field large format CCD’s connected to fast, low focal ratio telescopes. These are perfect for creating large sky vistas encompassing nebulae and larger galaxies like Messier 31 in Andromeda. For imaging competitions like the Astronomy Photographer of the Year competition, these wide field scopes are perfect for the beautiful skyscapes they can create.
Scopes like the Faulkes Telescope North, even though it has a huge 2m (almost the same size as the one on the Hubble Space Telescope) mirror, is configured for smaller fields of view, literally only around 10 arcminutes, which will nicely fit in objects like Messier 51, the Whirpool Galaxy, but would take many separate images to image something like the full Moon (If Faulkes North were set up for that, which it’s not). It’s advantage is aperture size and immense CCD sensitivity. Typically our team using them is able to image a magnitude +23 moving object (comet or asteroid) in under a minute using a red filter too!
A field of view with a scope like the twin Faulkes scopes, which are owned and operated byLCOGT is perfect for smaller deep sky objects and my own interests which are comets and asteroids.Many other research projects such as exoplanets and the study of variable stars are conducted using these telescopes.Many schools start out imaging nebulae, smaller galaxies and globular clusters, with our aim at the Faulkes Telescope Project office, to quickly get students moving on to more science based work, whilst keeping it fun. For imagers, mosaic approaches are possible to create larger fields, but this obviously will take up more imaging and telescope slew time.
Each robotic system has its own set of learning curves, and each can suffer from technical or weather related difficulties, like any complex piece of machinery or electronic system. Knowing a bit about the imaging process to begin with, sitting in on other’s observing sessions on things like Slooh, all helps. Also make sure you know your target field of view/size on the sky (usually in either right ascension and declination) or some systems have a “guided tour mode” with named objects, and make sure you can be ready to move the scope to it as quickly as possible, to get imaging. With the commercial robotic scopes, time really is money.
Global Rent-A-Scope interface
Magazines like Astronomy Now in the UK, as well as Astronomy and Sky and Telescope in the United States and Australia are excellent resources for finding out more, as they regularly feature robotic imaging and scopes in their articles. Online forums like cloudynights.com and stargazerslounge.com also have thousands of active members, many of whom regularly use robotic scopes and can give advice on imaging and use, and there are dedicated groups for robotic astronomy like the Online Astronomical Society. Search engines will also give useful information on what is available as well.
To get access to them, most of the robotic scopes require a simple sign up process, and then the user can either have limited free access, which is usually an introductory offer, or just start to pay for time. The scopes come in various sizes and quality of camera, the better they are, usually the more you pay. For education and school users as well as astronomical societies, The Faulkes Telescope (for schools) and the Bradford Robotic scope both offer free access, as does the NASA funded Micro Observatory project. Commercial ones like iTelescope, Slooh and Lightbuckets provide a range of telescopes and imaging options, with a wide variety of price models from casual to research grade instrumentation and facilities.
So what about my own use of Robotic Telescopes?
Personally I use mainly the Faulkes North and South scopes, as well as the Liverpool La Palma Telescope. I have worked with the Faulkes Telescope Project team now for a few years, and it’s a real honour to have such access to research grade intrumentation. Our team also use the iTelescope network when objects are difficult to obtain using the Faulkes or Liverpool scopes, though with smaller apertures, we’re more limited in our target choice when it comes to very faint asteroid or comet type objects.
After having been invited to meetings in an advisory capacity for Faulkes, late in 2011 I was appointed pro am program manager, co-ordinating projects with amateurs and other research groups. With regards to public outreach I have presented my work at conferences and public outreach events for Faulkes and we’re about to embark on a new and exciting project with the European Space Agency whom I work for also as a science writer.
My use of Faulkes and the Liverpool scopes is primarily for comet recovery, measurement (dust/coma photometry and embarking on spectroscopy) and detection work, those icy solar system interlopers being my key interest. In this area, I co-discovered Comet C2007/Q3 splitting in 2010, and worked closely with the amateur observing program managed by NASA for comet 103P, where my images were featured in National Geographic, The Times, BBC Television and also used by NASA at their press conference for the 103P pre-encounter event at JPL.
The 2m mirrors have huge light grasp, and can reach very faint magnitudes in very little time. When attempting to find new comets or recover orbits on existing ones, being able to image a moving target at magnitude 23 in under 30s is a real boon. I am also fortunate to work alongside two exceptional people in Italy, Giovanni Sostero and Ernesto Guido, and we maintain a blog of our work, and I am a part of the CARA research group working on comet coma and dust measurements, with our work in professional research papers such as the Astrophysical Journal Letters and Icarus.
The Imaging Process
When taking the image itself, the process starts really before you have access to the scope. Knowing the field of view, what it is you want to achieve is critical, as is knowing the capabilities of the scope and camera in question, and importantly, whether or not the object you want to image is visible from the location/time you’ll be using it.
First thing I would do if starting out again is look through the archives of the telescope, which are usually freely available, and see what others have imaged, how they have imaged in terms of filters, exposure times etc, and then match that against your own targets.
Ideally, given that in many cases, time will be costly, make sure that if you’re aiming for a faint deep sky object with tenuous nebulosity, you don’t pick a night with a bright Moon in the sky, even with narrowband filters, this can hamper the final image quality, and that your choice of scope/camera will in fact image what you want it to. Remember that others may also want to use the same telescopes, so plan ahead and book early. When the Moon is bright, many of the commercial robotic scope vendors offer discounted rates, which is great if you’re imaging something like globular clusters maybe, which aren’t as affected by the moonlight (as say a nebula would be)
Forward planning is usually essential, knowing that your object is visible and not too close to any horizon limits which the scope may impose, ideally picking objects as high up as possible, or rising to give you plenty of imaging time. Once that’s all done, then following the scope’s imaging process depends on which one you choose, but with something like Faulkes, it’s as simple as selecting the target/FOV, slewing the scope, setting the filter, and then exposure time and then waiting for the image to come in.
The number of shots taken depends on the time you have. Usually when imaging a comet using Faulkes I will try to take between 10 and 15 images to detect the motion, and give me enough good signal for the scientific data reduction which follows. Always remember though, that you’re usually working with vastly superior equipment than you have at home, and the time it takes to image an object using your home setup will be a lot less with a 2m telescope. A good example is that a full colour high resolution image of something like the Eagle Nebula can be obtained in a matter of minutes on Faulkes, in narrowband, something which would usually take hours on a typical backyard telescope.
For imaging a non moving target, the more shots in full colour or with your chosen filter (Hydrogen Alpha being a commonly used one with Faulkes for nebula) you can get the better. When imaging in colour, the three filters on the telescope itself are grouped into an RGB set, so you don’t need to set up each colour band. I’d usually add a luminance layer with H-Alpha if it’s an emission nebula, or maybe a few more red images if it’s not for luminance. Once the imaging run is complete, the data is usually placed on a server for you to collect, and then after downloading the FITS files, combine the images using Maxim (or other suitable software) and then on in to something like Photoshop to make the final colour image. The more images you take, the better the quality of the signal against the background noise, and hence a smoother and more polished final shot.
Between shots the only thing that will usually change will be filters, unless tracking a moving target, and possibly the exposure time, as some filters take less time to get the requisite amount of light. For example with a H-Alpha/OIII/SII image, you typically image for a lot longer with SII as the emission with many objects is weaker in this band, whereas many deep sky nebula emit strongly in the H-Alpha.
The Image Itself
NGC 6302 taken by Thomas Mills High School with the Faulkes Telescope
As with any imaging of deep sky objects, don’t be afraid to throw away poor quality sub frames (the shorter exposures which go to make up the final long exposure when stacked). These could be affected by cloud, satellite trails or any number of factors, such as the autoguider on the telescope not working correctly. Keep the good shots, and use those to get as good a RAW stacked data frame as you can. Then it’s all down to post processing tools in products like Maxim/Photoshop/Gimp, where you’d adjust the colours, levels, curves and possibly use plug ins to sharpen up the focus, or reduce noise. If it’s pure science your interested in, you’ll probably skip most of those steps and just want good, calibrated image data (dark and flat field subtracted as well as bias)
The processing side is very important when taking shots for aesthetic value, it seems obvious, but many people can overdo it with image processing, lessening the impact and/or value of the original data. Usually most amateur imagers spend more time on processing than actual imaging, but this does vary, it can be from hours to literally days doing tweaks. Typically when processing an image taken robotically, the dark and flat field calibration are done. First thing I do is access the datasets as FITS files, and bring those in to Maxim DL. Here I will combine and adjust the histogram on the image, possible running multiple iterations of a de-convolution algorithm if the start points are not as tight (maybe due to seeing issues that night).
Once the images are tightened up and then stretched, I will save them out as FITS files, and using the free FITS Liberator application bring them in to Photoshop. Here, additional noise reduction and contrast/level and curve adjustments will be made on each channel, running a set of actions known as Noels actions (a suite of superb actions by Noel Carboni, one of the worlds foremost imaging experts) can also enhance the final individual red green and blue channels (and the combined colour one).
Then, I will composite the images using layers into a colour final shot, adjusting this for colour balance and contrast. Possibly running a focus enhancement plug in and further noise reduction. Then publish them via flickr/facebook/twitter and/or submit to magazines/journals or scientific research papers depending on the final aim/goals.
Serendipity can be a wonderful thing
I got in to this quite by accident myself…. In March 2010, I had seen a posting on a newsgroup that Comet C/2007 Q3, a magnitude 12-14 object at the time, was passing near to a galaxy, and would make an interesting wide field side by side shot. That weekend, using my own observatory, I imaged the comet over several nights, and noticed a distinct change in the tail and brightness of the comet over two nights in particular.
Comet C/2007 Q3. Credit: Nick Howes
A member of the BAA (British Astronomical Association), seeing my images, then asked if I would submit them for publication. I decided however to investigate this brightening a bit further, and as I had access to the Faulkes that week, decided to point the 2m scope at this comet, to see if anything unusual was taking place. The first images came in, and I immediately, after loading them in to Maxim DL and adjusting the histogram, noticed that a small fuzzy blob appeared to be tracking the comet’s movement just behind it. I measured the separation as only a few arc-seconds, and after staring at it for a few minutes, decided that it may have fragmented.
I contacted Faulkes Telescope control, who put me in touch with the BAA comet section director, who kindly logged this observation the same day. I then contacted Astronomy Now magazine, who leapt on the story and images and immediately went to press with it on their website. The following days the media furore was quite literally incredible.
Interviews with national newspapers, BBC Radio, Coverage on the BBC’s Sky at Night television show, Discovery Channel, Radio Hawaii, Ethiopia were just a few of the news/media outlets that picked up the story.. the news went global that an amateur had made a major astronomical discovery from his desk using a robotic scope. This then led on to me working with members of the AOP project with the NASA/University of Maryland EPOXI mission team on imaging and obtaining light curve data for comet 103P late in 2010, again which led to articles and images in National Geographic, The Times and even my images used by NASA in their press briefings, alongside images from the Hubble Space Telescope. Subscription requests to Faulkes Telescope Project as a result of my discoveries went up by hundreds of % from all over the world.
In summary
Robotic telescopes can be fun, they can lead to amazing things, this past year, a work experience student I was mentor for with the Faulkes Telescope Project, imaged several fields we’d assigned to her, where our team then found dozens of new and un-catalogued asteroids, and she also managed to image a comet fragmenting. Taking pretty pictures is fun, but the buzz for me comes with the real scientific research I am now engaged in, and it’s a pathway I aim to stay on probably for the rest of my astronomical lifetime. For students and people who don’t have the ability to either own a telescope due to financial or possibly location constraints, it’s a fantastic way to do real astronomy, using real equipment, and I hope, in reading this, you’re encouraged to give these fantastic robotic telescopes a try.
The Atacama Desert of Chile has been called “an astronomer’s paradise,” with its stunningly dark, steady and transparent skies. It is home to some of the world’s leading telescopes, such as the Very Large Telescope (VLT) is located on Paranal. Babak Tafreshi, an astronomer, journalist and director of The World at Night (TWAN) is creating a series of timelapse videos from Paranal, and this is his latest. Just beautiful. You can see more at his Vimeo page.
