Webb Telescope Captures Five Different, Dazzling Views of a Nearby Galaxy (inverse.com) 29
Long-time Slashdot reader schwit1 shares a report from Inverse:
It only took 25 years of development, 17 years of construction, eight launch delays, and five months of alignments, but finally, the James Webb Space Telescope is almost ready for prime time. New photos released by the European Space Agency — and an accompanying video from NASA — show images of stars taken by a fully aligned space telescope, instruments and all.
The image shows snapshots from each of Webb's three imaging instruments, plus its spectrograph and guidance sensor. The images show a field of stars in the Large Magellanic Cloud (LMC), a galaxy near the Milky Way about 158,000 light-years away. If it orbits our galaxy, it would be, by far, the largest satellite galaxy. But there's a chance it's just passing through or slowly merging with our galaxy.
The image shows snapshots from each of Webb's three imaging instruments, plus its spectrograph and guidance sensor. The images show a field of stars in the Large Magellanic Cloud (LMC), a galaxy near the Milky Way about 158,000 light-years away. If it orbits our galaxy, it would be, by far, the largest satellite galaxy. But there's a chance it's just passing through or slowly merging with our galaxy.
Takes pictures from different angles. (Score:1)
Say what?
Re:Takes pictures from different angles. (Score:5, Informative)
Neither TFS nor TFA says the photos were taken from different angles.
The "five views" refer to images of the same star cluster taken with five different instruments.
Re: (Score:2, Informative)
The instruments are next to each other in the focal plane, so each has a slightly different view.
Re: (Score:2)
At those distances? Not really.
More likely they are filtered for different spectra. These telescopes for all their fanciness run on the same principle the dinky casegrains or newtonians we use in amateur astronomy. You put the fatest black and white camera you can in them and throw a filter over the front to pick out the frequencies your after. you might take a number of successive shots with different filters for things like Hydrogen emmision lines, carbon, oxygen, whatever (Amateur astronomers oft use a f
Re: (Score:2)
Re:Takes pictures from different angles. (Score:5, Informative)
Um, no. JWST has 4 instruments. NIRcam is a camera for near-infrared. NIRSpec is a spectroscope for NIR, NIRISS is another spectroscope, MIRI is a mid-infrared instrument. #5 is the guidance sensor.
NIRcam, NIRspec and NIRISS all use Teleyne H2RG sensors, but they have different filter fits, and obvs the spectroscopes have grisms etc. that the camera lacks.
These are placed next to each other in the field of view [stsci.edu], so yes, they look at different parts of the sky. NIRcam and NIRspec are about 100 arcseconds apart.
Re: (Score:2)
Re: (Score:3)
About $160k each.
Re: (Score:3)
At those distances? Not really.
At what distances? You're talking about the small side of a focal plane. If your sensors are at a different location on that focal plane unless you split the image to all instruments at once with a prism or use a mirror to only engage one instrument at a time (which the JWST doesn't do) all four sensors will see different images.
No they don't have fixed filters
They aren't even all cameras (one of them was a visual interpretation from a spectrograph)
No they aren't aligned to see the same image. (Hint: There'
Re:Takes pictures from different angles. (Score:5, Funny)
Re: (Score:2)
Re: (Score:3, Informative)
Re:Takes pictures from different angles. (Score:4, Funny)
Don't worry. The next generation of space telescopes are designed to show the dark side of those stars.
Re: (Score:2)
Deserved the Funny mod, but can you do one about which is the real "First Light" image? Or does that "old astronomy" idea still apply these days? Heck, they probably aren't even looking at visible light anymore?
"Get off my lawn, you whippersnappers," says HST. "Back in my day, we had First Light like real telescopes."
Re: (Score:1)
At these distances, even showing just the outside of those stars is tricky enough.
Re: (Score:2)
It's not really that hard, if you use indirect imaging. You point the camera away from what you're trying to observe, zoom in, and then photograph. After you have that image, you just decrop it to get what you want.
Re: (Score:2)
Well, they just have to tell the UI to "enhance" and they'll get the other angles.
Re: (Score:2)
It is showing the other side as well. You just have to zoom in alot and enhance the image to get to see the universe circle around so that you can see yourself again! /joke!
Almost ready? (Score:2)
Instrument commissioning will take about 2 months. The first science will be done by the end of June.
Re:Almost ready? (Score:5, Insightful)
Yes, in a timescale that ranges from 1996 to 2022, being just 2 months out definitely fits the definition of "almost ready".
Difference in resolution (Score:5, Interesting)
This Twitter post [twitter.com] shows the difference in resolving capabilities between WISE, Spitzer and now Webb.
As the poster indicated, Spitzer came before WISE but he wanted to show the difference since WISE was an all-sky telescope.
Wow! (Score:2)
Cool lens flare.
Re: (Score:1)
There's a good explanation of the diffraction spikes coming off the star here [medium.com].
TLDR version: They're caused by the supports for the secondary mirror.
Re: (Score:2)
They're caused by the edges of the primary mirror segments (those cause the 6 large spikes) and the supports for the secondary mirror (these cause the 2 smaller horizontal spikes).