NASA - James Webb Space Telescope - Updates Thread

[deadman1204]

Yes. It is Guest Observer proposal 1618

It will use MIRI and its coronagraph to directly image alpha Cen A.

Note: it has a 12-month proprietary period, so public results might not be this year.

https://www.stsci.edu/jwst/science-execution/program-information.html?id=1618

--- Tony

ABSTRACT
Alpha Centauri A is the closest solar-type star to the Sun and offers an unique opportunity to detect both a mature gas giant planet (consistent with existing radial velocity constraints) and a zodiacal dust cloud. A carefully planned observational sequence using the MIRI Coronagraph (F1550C) and innovative post-processing would be sensitive down to a radius limit of 0.5~0.7 R-Jupiter for planets within ~3 AU (~2.5”) around alpha Cen A where models predict a region of stability against disruption by alpha Cen B. These same observations would be sensitive to a level of zodiacal
emission only a few times brighter than that of the Sun’s, an unprecedented level not even achieved by ground based interferometers. The proposed observations would probe the limit of JWST high contrast imaging on a star that offers the best chance for the ultimate detection of Earth analogs by future ground and/or space based facilities. The experiment is admittedly high risk, but the prospect of directly imaging a planet around our closest stellar neighbor is an exciting one.

Bold emphasis mine.

They are going to try to directly image a planet half the size of Jupiter!  Even if they don't succeed, they get to try out a technique that may be used in the future.

They are also going to try to image the zodiacal light. Question: Are trace CFC gases in the zodiacal light something they could register with the spectrometer at this distance? There are obvious world-shattering implications if they see any...

How would CFC's in the zodiacal light be "world shattering". The zodiacal light is reflected light from sol inside the solar system.

[Zaum]

Question: Are trace CFC gases in the zodiacal light something they could register with the spectrometer at this distance?

I don't believe that's something that's been studied, but even the detection of CFCs in planetary atmospheres is considered very challenging, so I imagine the answer is no.

The zodiacal light is reflected light from sol inside the solar system.

In this case they aim to detect an "exo-zodiacal light" -- ie, dust in Alpha Cen A's system.

[Star One]

JWST detects ‘coldest ices measured to date in a molecular cloud’:

[CuddlyRocket]

They are also going to try to image the zodiacal light. Question: Are trace CFC gases in the zodiacal light something they could register with the spectrometer at this distance? There are obvious world-shattering implications if they see any...

How would CFC's in the zodiacal light be "world shattering". The zodiacal light is reflected light from sol inside the solar system.

Observing CFCs in the atmospheres of exoplanets is considered by astronomers as compelling evidence of a technosignature as they are only produced in significant quantities on Earth by industrial processes. So, reasoning by analogy ...

[Star One]

JWST sees ringed Charilklo asteroid occult star:

[cAsE-sEnSlTivE]

https://www.space.com/james-webb-space-telescope-niriss-glitch

"On Jan. 15, JWST's Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument "experienced a communications delay within the instrument, causing its flight software to time out," according to a Jan. 24 statement (opens in new tab) from NASA. NIRISS can't currently be used for science, the statement noted."

[Eric Hedman]

They are also going to try to image the zodiacal light. Question: Are trace CFC gases in the zodiacal light something they could register with the spectrometer at this distance? There are obvious world-shattering implications if they see any...

How would CFC's in the zodiacal light be "world shattering". The zodiacal light is reflected light from sol inside the solar system.

Observing CFCs in the atmospheres of exoplanets is considered by astronomers as compelling evidence of a technosignature as they are only produced in significant quantities on Earth by industrial processes. So, reasoning by analogy ...

Zodiacal light is not from the atmosphere of a planet.  It is light reflected from the dust floating in space around a star.  In our solar system the figure I get for the dust that reflects zodiacal light is the particles have a total volume equivalent to a 30 km sphere broken down into dust, that is a reflective surface many orders of magnitude greater than Earth's surface.  CFCs are an incredibly small percent of our atmosphere.  I highly doubt you would be able to find the signature of CFCs in the atmosphere of a planet within that dust cloud within all that light noise from zodiacal light.

CFCs in our atmosphere can be monitored by satellites.  The Aura satellite uses a microwave limb sounder to build a vertical profile of the gasses in our atmosphere.  The microwaves are emitted by the gasses and not part of reflected sunlight.  But to do it at stellar distances, is more than likely going to be beyond our technical capabilities for a long time if ever.  So looking for CFCs from a planet buried inside the cloud of dust reflecting sunlight isn't likely to find CFCs anytime soon.

[CuddlyRocket]

They are also going to try to image the zodiacal light. Question: Are trace CFC gases in the zodiacal light something they could register with the spectrometer at this distance? There are obvious world-shattering implications if they see any...

How would CFC's in the zodiacal light be "world shattering". The zodiacal light is reflected light from sol inside the solar system.

Observing CFCs in the atmospheres of exoplanets is considered by astronomers as compelling evidence of a technosignature as they are only produced in significant quantities on Earth by industrial processes. So, reasoning by analogy ...

Zodiacal light is not from the atmosphere of a planet.  It is light reflected from the dust floating in space around a star.  In our solar system the figure I get for the dust that reflects zodiacal light is the particles have a total volume equivalent to a 30 km sphere broken down into dust, that is a reflective surface many orders of magnitude greater than Earth's surface.  CFCs are an incredibly small percent of our atmosphere.  I highly doubt you would be able to find the signature of CFCs in the atmosphere of a planet within that dust cloud within all that light noise from zodiacal light.

CFCs in our atmosphere can be monitored by satellites.  The Aura satellite uses a microwave limb sounder to build a vertical profile of the gasses in our atmosphere.  The microwaves are emitted by the gasses and not part of reflected sunlight.  But to do it at stellar distances, is more than likely going to be beyond our technical capabilities for a long time if ever.  So looking for CFCs from a planet buried inside the cloud of dust reflecting sunlight isn't likely to find CFCs anytime soon.

I obviously put it obscurely, so trying to be clearer: The (probably tongue-in-cheek) original suggestion seemed to be that there would be world-shattering implications if they see traces of CFCs in the zodiacal light generally - i.e. from the circum-stellar dust; not specifically from any exoplanets - as it would be taken as evidence of widespread in-space industrial activity in the stellar system.

[Star One]

JWST sees ‘field of galaxies’ in 4K:

[bolun]

Webb detects extremely small main-belt asteroid

A previously unknown 100–200-metre asteroid — roughly the size of Rome’s Colosseum — has been detected by an international team of European astronomers using the NASA/ESA/CSA James Webb Space Telescope. Their project used data from the calibration of the Mid-InfraRed Instrument (MIRI), in which the team serendipitously detected an interloping asteroid. The object is likely the smallest observed to date by Webb and may be an example of an object measuring under 1 kilometer in length within the main asteroid belt, located between Mars and Jupiter. More observations are needed to better characterize this object’s nature and properties.

[Star One]

First Observations of the Brown Dwarf HD 19467 B with JWST

We observed HD 19467 B with JWST's NIRCam in six filters spanning 2.5-4.6 μm with the Long Wavelength Bar coronagraph. The brown dwarf HD 19467 B was initially identified through a long-period trend in the radial velocity of G3V star HD 19467. HD 19467 B was subsequently detected via coronagraphic imaging and spectroscopy, and characterized as a late-T type brown dwarf with approximate temperature ∼1000K. We observed HD 19467 B as a part of the NIRCam GTO science program, demonstrating the first use of the NIRCam Long Wavelength Bar coronagraphic mask. The object was detected in all 6 filters (contrast levels of 2×10−4 to 2×10−5) at a separation of 1.6 arcsec using Angular Differential Imaging (ADI) and Synthetic Reference Differential Imaging (SynRDI). Due to a guidestar failure during acquisition of a pre-selected reference star, no reference star data was available for post-processing. However, RDI was successfully applied using synthetic Point Spread Functions (PSFs) developed from contemporaneous maps of the telescope's optical configuration. Additional radial velocity data (from Keck/HIRES) are used to constrain the orbit of HD 19467 B. Photometric data from TESS are used to constrain the properties of the host star, particularly its age. NIRCam photometry, spectra and photometry from literature, and improved stellar parameters are used in conjunction with recent spectral and evolutionary substellar models to derive physical properties for HD 19467 B. Using an age of 9.4±0.9 Gyr inferred from spectroscopy, Gaia astrometry, and TESS asteroseismology, we obtain a model-derived mass of 62±1MJ, which is consistent within 2-σ with the dynamically derived mass of 81+14−12MJ

https://arxiv.org/abs/2301.11455

[Star One]

JWST delivers stunning views of “PHANGS” galaxies:

[Star One]

JADES Imaging of GN-z11: Revealing the Morphology and Environment of a Luminous Galaxy 430 Myr After the Big Bang

We present JWST NIRCam 9-band near-infrared imaging of the luminous z=10.6 galaxy GN-z11 from the JWST Advanced Deep Extragalactic Survey (JADES) of the GOODS-N field. We find a spectral energy distribution (SED) entirely consistent with the expected form of a high-redshift galaxy: a clear blue continuum from 1.5 to 4 microns with a complete dropout in F115W. The core of GN-z11 is extremely compact in JWST imaging. We analyze the image with a two-component model, using a point source and a Sérsic profile that fits to a half-light radius of 200 pc and an index n=0.9. We find a low-surface brightness haze about 0.4′′ to the northeast of the galaxy, which is most likely a foreground object but might be a more extended component of GN-z11. At a spectroscopic redshift of 10.60 (Bunker et al. 2023), the comparison of the NIRCam F410M and F444W images spans the Balmer jump. From population synthesis modeling, here assuming no light from an active galactic nucleus, we reproduce the SED of GN-z11, finding a stellar mass of ∼109 M, a star-formation rate of ∼20 M yr−1 and a young stellar age of ∼20 Myr. As massive galaxies at high redshift are likely to be highly clustered, we search for faint neighbors of GN-z11, finding 9 galaxies out to ∼5 comoving Mpc transverse with photometric redshifts consistent with z=10.6, and a 10th more tentative dropout only 3′′ away.

https://arxiv.org/abs/2302.07234

[Targeteer]

Airing now on PBS in the states...  https://www.pbs.org/video/new-eye-on-the-universe-zvzqn1/

Join scientists as they use NASA’s brand new James Webb Space Telescope to peer deep in time to hunt for the first stars and galaxies in our universe, and try to detect the fingerprints of life in the atmospheres of distant exoplanets

Airing: 02/22/23

[FutureSpaceTourist]

[Star One]

NASA’s Webb Telescope Captures Rarely Seen Prelude to Supernova

https://www.nasa.gov/feature/goddard/2023/nasa-s-webb-telescope-captures-rarely-seen-prelude-to-supernova