Photobombing a star! Thousands of distant and ancient galaxies can be seen in the background of the first in focus image from NASA’s James Webb Space Telescope – including some we’ve never seen before
- The James Webb Space Telescope is a joint project of NASA, ESA and the CSA
- It launched from the European spaceport in French Guiana on Christmas Day
- The $10 billion observatory is designed to peer deep into the early universe
- It will also allow astronomers to study the atmosphere of distant exoplanets
- This latest miilestone includes the first fully focus image of a single star
NASA’s James Webb Space Telescope was ‘photobombed’ by thousands of ancient and distant galaxies, when it took its first ‘in focus’ image of a single star.
The $10 billion observatory is going through months of commissioning, including aligning and focusing each of its 18 mirror segments so they work as one mirror.
A star called 2MASS J17554042+6551277 is visible in the foreground of the stunning image – found 2,000 light years, although the background galaxies are millions, if not billions of light years from the Earth – reaching back to the early universe.
This is just a test shot form the Webb telescope, the latest engineering image, with the ‘pretty pictures’ and science releases not due until later this summer.
It was designed to see how well the 18 hexagonal mirrors worked together for a single coordinated image, and it was ‘better than expected’, providing a much more tightly focused view of the universe, that will improve scientific measurements.
NASA says the image is so good that the optical performance from Webb ‘will be able to meet or exceed the science goals the observatory was built to achieve.’
‘More than 20 years ago, the Webb team set out to build the most powerful telescope that anyone has ever put in space and came up with an audacious optical design to meet demanding science goals,’ said Thomas Zurbuchen, NASA associate administrator. ‘Today we can say that design is going to deliver.’
It has now completed a series of critical mirror alignment steps, known as ‘fine phasing’, revealing an in focus image of the star, 2MASS J17554042+6551277
Webb was launched from the European spaceport in French Guiana on Christmas Day last year, arriving at its final orbit between Earth and the sun on January 24.
It has spent the past few weeks calibrating its mirrors, and slowly bringing each of them into focus – through a series of engineering images.
Last month, NASA looked at a much closer star with 18 separate images from its mirror segments – revealed as a mosaic.
Scientists said they were giddy as they watched the latest test photos arrive. NASA´s test image was aimed at a star 100 times fainter than the human eye can see – 2,000 light-years away. A light-year is nearly 6 trillion miles (9.7 trillion kilometers).
The shape of Webb’s mirrors and its filters made the shimmering star look more red and spiky but the background really stole the show.
‘You can’t help but see those thousands of galaxies behind it, really gorgeous,’ said Jane Rigby, Webb operations project scientist.
Those galaxies are several billions of years old. Eventually, scientists hope Webb will see so faraway and back in time that it will only be ‘a couple hundred million years after the Big Bang,’ she said.
Dr Jenifer Millard, extragalactic astronomer, took a tour of some of the galaxies seen within the background of the image on Twitter, describing them as ‘amazing’.
Among them was a spiral galaxy near the bottom of the image with hints of a neighbour coming in for a collision.
There were also ‘face on spiral galaxies’, that reveal what a galaxy like the Milky Way might look like if we could look at it from above.
There was also evidence of galaxy clusters, recent mergers of two galaxies, and some that were from near the dawn of the universe.
It also took an updated, in focus mirror selfie – now that all 18 segments have been aligned and focused for the first time
Some are very tiny blobs of light in the far background of the image, barely visible.
‘The closer you look, the more these small blobs appear – and these are the really exciting ones, the oldest,’ said Dr Millard on Twitter.
However, they won’t be the oldest galaxies Webb can see – as this image was taken with just 35 minutes exposure – older galaxies will need more time to see.
‘But the very first stars and galaxies, they’ll need more than 35 mins of staring to find. Imagine how full this will be with 10 days of staring into deep-space.’
Luca Cortesa, an astronomer with ICRAR, compared some of the background galaxies to images of the same galaxies taken with Earth-based observatories.
‘Like many astronomers on the planet, I had some fun comparing the amazing #NASAWebb alignment image with ground-based optical images.
Dr Jenifer Millard, extragalactic astronomer, took a tour of some of the galaxies seen within the background of the image on Twitter , describing them as ‘amazing’
Among them was a spiral galaxy near the bottom of the image with hints of a neighbour coming in for a collision
‘Seeing the difference with real data is jaw-dropping. Well done (and thank you!) to all people involved, it will be an exciting ride,’ he said on Twitter.
The tennis court-sized $10 billion observatory is now fully focused, after each of the 18 mirror segments were aligned to within a fraction of the width of a human hair.
The work of the focusing team isn’t done though, this is just the latest major milestone in the unfolding, preparation, focusing and cooling of the telescope.
This stage involved checking every optical parameter, as well as having them tested, finding it is performing at, or above, expectations.
Luca Cortesa, an astronomer with ICRAR, compared some of the background galaxies to images of the same galaxies taken with Earth-based observatories
The team also found no critical issues and no measurable contamination or blockages to Webb’s optical path. The observatory is able to successfully gather light from distant objects and deliver it to its instruments without issue.
Although there are months to go before Webb ultimately delivers its new view of the cosmos, achieving this milestone means the team is confident that Webb’s first-of-its-kind optical system is working as well as possible.
Instruments on the James Webb Space Telescope
NIRCam (Near InfraRed Camera) an infrared imager from the edge of the visible through the near infrared
NIRSpec (Near InfraRed Spectrograph) will also perform spectroscopy over the same wavelength range.
MIRI (Mid-InfraRed Instrument) will measure the mid-to-long-infrared wavelength range from 5 to 27 micrometers.
FGS/NIRISS (Fine Guidance Sensor and Near Infrared Imager and Slitless Spectrograph), is used to stabilize the line-of-sight of the observatory during science observations.
Senior Advisor for Science & Exploration at the European Space Agency, and Webb scientist, Mark McCaughrean, said Webb was now ‘sending the sharpest possible images to its instruments.
‘That means we can go deep & see lots of detail, & deliver the amazing science that was dreamed of decades ago.’
In the background of the stunning bright star image are galaxies, and clusters of galaxies, that hint at what Webb will show us once fully online.
Hannah Wakeford, exoplanet scientist from the University of Bristol, said on Twitter: ‘Look at some of those galaxy clusters in the background!
‘This telescope is going to amaze us at every step. And with a point of light we can measure the atmospheres of otherwise invisible planets.’
This is in part possible due to its unique optical system and design – that required it to be folded for launch, and gradually unfolded over a month.
While some of the largest ground-based telescopes on Earth use segmented primary mirrors, Webb is the first telescope in space to use such a design.
The 21-foot, 4-inch primary mirror is made up of 18 hexagonal, beryllium mirror segments. Once it reached its orbit, each mirror was adjusted to within nanometers, in order to form a single, large mirror surface to gather even the faintest light.
Being able to detect faint infrared light will allow astronomers to use Webb to peer deeper into the early universe, or detect faint atmospheres on distant worlds.
‘In addition to enabling the incredible science that Webb will achieve, the teams that designed, built, tested, launched, and now operate this observatory have pioneered a new way to build space telescopes,’ said Lee Feinberg, Webb optical telescope element manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
Webb was launched from the European spaceport in French Guiana on Christmas Day last year, arriving at its final orbit between Earth and the sun on January 24
This early Webb alignment image, called an ‘image array’, shows dots of starlight arranged in a pattern similar to the honeycomb shape of the primary mirror
The James Webb team moved the primary mirror segments to arrange the dots of starlight into a hexagonal image array. Here, each dot of starlight is labeled with the corresponding mirror segment that captured it
The University of Arizona-developed and managed Near Infrared Camera onboard NASA’s James Webb Space Telescope helped the telescope achieve this milestone.
Over the last few months, NIRCam has been used to focus the individual 18 mirror segments, at first creating unaligned mosaics – with 18 pictures of the same star.
Then, the mirrors aligned enough to create an image of a single out-of-focus star.
The latest image shows a different target star from previous images, but in focus.
The Webb team also took another primary mirror ‘selfie’ now that the mirrors are totally aligned. This time in focus, rather than slightly blurred.
In February, NASA released an image that showed the 18 mirror segments as they look from the secondary mirror. In that ‘selfie’ image, one of the mirror segments glowed more brightly than the rest because it was pointed at the bright star HD 84406, while the 17 others weren’t in the same alignment.
The images included a ‘selfie’ of $10 billion (£7.4 billion) telescope’s primary mirror (pictured)
This image mosaic, which shows 18 randomly positioned copies of the same star, served as the starting point for the alignment process
Now that the mirrors are aligned, all mirror segments glow brightly in the latest selfie. The image was created using a specialized pupil imaging lens inside NIRCam.
While the photos captured so far, known as ‘engineering images,’ mark major milestones, there is still a lot to be done in the coming months to prepare the rest of the observatory for full scientific operations using all four of its instruments.
The first ‘pretty’ images, taken for scientific purposes, are expected in the summer.
‘Demonstrating this high level of optical performance ensures that NIRCam will deliver the science results that everyone is hoping for,’ said Marcia Rieke, principal investigator for the NIRCam instrument and a UArizona Regents Professor.
‘The telescope is working absolutely fabulously and will reveal the fine details that we want to see.’
With the fine phasing stage of the telescope’s alignment complete, the team has now fully aligned Webb’s primary imager, NIRCam, to the observatory’s mirrors.
‘We have fully aligned and focused the telescope on a star, and the performance is beating specifications. We are excited about what this means for science,’ said Ritva Keski-Kuha, deputy optical telescope element manager for Webb at NASA Goddard. ‘We now know we have built the right telescope.’
Over the next six weeks, the team will proceed through the remaining alignment steps before final science instrument preparations.
James Webb’s primary mirror consists of 18 hexagonal segments of gold-plated beryllium metal, and measures 21 feet 4 inches (6.5 metres) in diameter. It is supported by three shallow carbon fiber tubes, or struts, that extend outwards
The team will further align the telescope to include the Near-Infrared Spectrograph, the Near InfraRed Imager and Slitless Spectrograph and the Mid-Infrared Instrument, or MIRI, which is led by UArizona Regents Professor of Astronomy George Rieke.
In this phase of the process, an algorithm will evaluate the performance of each instrument and then calculate the final corrections needed to achieve a well-aligned telescope across all science instruments.
Following this, Webb’s final alignment step will begin, and the team will adjust any small, residual positioning errors in the mirror segments.
The team is on track to conclude all aspects of Optical Telescope Element alignment by early May, if not sooner, before moving on to approximately two months of science instrument preparations.
THE JAMES WEBB TELESCOPE
The James Webb telescope has been described as a ‘time machine’ that could help unravel the secrets of our universe.
The telescope will be used to look back to the first galaxies born in the early universe more than 13.5 billion years ago, and observe the sources of stars, exoplanets, and even the moons and planets of our solar system.
The vast telescope, which has already cost more than $7 billion (£5 billion), is considered a successor to the orbiting Hubble Space Telescope
The James Webb Telescope and most of its instruments have an operating temperature of roughly 40 Kelvin – about minus 387 Fahrenheit (minus 233 Celsius).
Officials say the cost may exceed the $8 billion (£5.6 billion) program cap set by Congress. The space agency has already poured $7 billion (£5 billion) into the telescope.
When it is launched in 2021, it will be the world’s biggest and most powerful telescope, capable of peering back 200 million years after the Big Bang.
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