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Ori Fox❓ Profile picture
Ori Fox❓
@fox_ori
Astronomer | #JWST MIRI Scientist @STScI | Project Scientist for JWST Data Analysis Software #Jdaviz
Jan 18, 2022 • 22 tweets • 8 min read
Here is that promised story of the #JWST light sensors! aka – detectors. These devices are slightly larger than a quarter, but cost a quarter-MILLION dollars each! And key to the entire mission of detecting photons emitted 13 billion years ago at the edge of the Universe. 1/n 3/4 instruments (NIRCam,NIRSpec,NIRISS) have a total of 15 near-infrared detectors, optimized to detect light with a wavelength between 0.6-5 micrometers. Why IR? Universe expands -> far objects move away faster -> DOPPLER EFFECT makes them red -> Infrared looks back in time! 2/n
Jan 6, 2022 • 14 tweets • 6 min read
Bored while waiting for #jwst's mirrors to open tomorrow? Let's have a small technical chat about the optical design in the mean time. 1/n 🧵
webb.nasa.gov/content/observ… If you didn't know, #jwst is a three mirror anastigmat telescope that works slightly off-axis. A couple very interesting notes:
1) It has an effective vocal length of 131 meters!
2) The primary mirror is concave and the secondary mirror is convex.

2/n