In Space News: JWST: first science images, future goals, micrometeroid damage
Last week, NASA revealed a set of the first science-quality images from the Webb telescope. These included:
· A deep field image similar to the ones produced by Hubble, but of much higher quality.
· A spectrographic analysis of an exoplanet atmosphere, demonstrating presence of water vapor.
· Near- and mid-infrared images of several spectacular astronomical objects
· Later, a near-infrared image of Jupiter, demonstrating Webb’s capability to image objects in our Solar system.
CBS News presented analysis of the new images by the principal scientists (the production values were awful, many of the remotes failed to connect, had to fast forward through about half, but the rest was very informative):
NASA reveals more color images from the James Webb Space Telescope [CBS News]
Space.com has continued to update incoming information, including the Jupiter image:
NASA's James Webb Space Telescope mission: Live updates [Space.com]
More images and analysis:
NASA delivers first batch of images from James Webb Space Telescope [Astronomy.com]
Sky and Telescope has an article on future goals for the Webb observatory:
What the James Webb Space Telescope's First Year Will Reveal
Pretty sure the email services will truncate this post due to the images, but in the interest of size, I’ll just review a selection of the images. (Images credit: NASA, ESA, CSA, and STScI)
This is a deep stare at a tiny portion of sky, much like Hubble’s deep field studies (which Webb is to repeat at higher resolution later). Webb’s much greater infrared imaging capabilities allow imaging of much farther, more red-shifted objects. The image contains numerous very red galaxies, many distorted by the gravity of nearer galaxies into curved shapes. Also, Webb can image more distant objects without exploiting “gravitational lensing”, as Hubble did.
This is the Carina Nebula. The image shows giant, extremely hot stars in the upper portion. The lower part shows the impact of the extreme radiation and stellar wind on the nearby gas and dust. The shock and pressure in the surrounding matter causes it to be compressed into new stars; a stellar “nursery”. The detail in the infrared image is extraordinary.
One of the points made in the presentation from CBS was the different roles of near- and mid-infrared instruments on Webb. Some of the images demonstrate the different information obtained with each band of wavelengths.
This is the Southern Ring Nebula, formed by a dying star (I’ll find it’s mass category soon) casting off it’s outer layers into the surrounding gas and dust. The NIR image emphasizes the structure of the surrounding environment, while the MIR shows details of the interior. The MIR images from Webb are able to resolve the two stars of the binary system for the first time, and the shroud of dust surrounding the dying partner.
These are from Stephan's Quintet, a system of galaxies bound together by their mutual gravity. These show a tail of visible matter being dragged out of the middle galaxy. The MIR image of the topmost galaxy shows a very bright object, thought to be the accretion disc of a supermassive black hole.
Unfortunately, engineers have determined that a micrometeroid that struck Webb in May has done more damage than pre-launch predictions anticipated. They have been able to correct for most of the distortion of the damaged mirror segment, but not all. The overall impact on the capability of the telescope is expected to be slight.
I’m wondering what the unexpected degree of damage from the L2 environment will mean for the service life of the observatory. Webb’s very large main mirror meant they couldn’t enclose it in in a tube like Hubble’s. Mitigations that have been mentioned include turning Webb away from the direction of travel when possible.
This is a pre-launch versus post-impact image of the main mirror.