![]() Next, a plan for long term-monitoring will be enacted, while the team continues to investigate the cause, identify risks, and explore mitigations that would potentially improve performance. Further test observations will be taken to completely characterize the nature of the issue using this particular mode of observation. The team will gather all relevant ground test and flight data to fully assess MRS performance. ![]() The Webb team will continue MIRI observations as planned. NASA and its partners are developing a systematic plan to approach, analyze, and then explore the issue. ![]() All other observation modes – within MIRI and each of Webb’s other scientific instruments – remain unaffected. No effect has been seen for MIRI imaging, and there is no risk to the instrument. Further analysis of MIRI’s Medium Resolution Spectroscopy (MRS) mode revealed that at the longest wavelengths, the throughput, or the amount of light that is ultimately registered by MIRI’s sensors, has decreased since commissioning last year. This month, while performing calibration by comparing the brightness of standard stars that have been well-cataloged by other observatories to what Webb’s Mid-Infrared Instrument (MIRI) was receiving, team members noticed a discrepancy in the data. Mid-Infrared Instrument Operations Update All 17 observing modes of the James Webb Space Telescope undergo routine performance monitoring and calibration. The results have been published in the Astrophysical Journal Letters. So extreme distances in the early universe are referenced by how much the light emitted there has been shifted as it travelled through space to be detected by a telescope. Shorter wavelengths, for example ultraviolet and X-ray, are toward the bluer end of the electromagnetic spectrum. At extreme distances, astronomers use the redshift reference to account for the fact that, as the universe expands, wavelengths of light are stretched and “shifted” to redder wavelengths, which are longer. Before Webb, astronomers did not have high resolution imaging or spectral infrared data available to do this type of science. Galaxy YD4, previously estimated to be at a further distance based on imaging data alone, was able to be more accurately placed at the same redshift as the other galaxies. Astronomers used Webb's Near-Infrared Spectrograph (NIRSpec) instrument to precisely measure the distances and determine that the galaxies are part of a developing cluster. Webb picked up the investigation, focusing on the galaxies scouted by Hubble and gathering detailed spectroscopic data in addition to imagery. However, because Hubble cannot detect light beyond near-infrared, there is only so much detail it can see. The program dedicated Hubble time to observations using gravitational lensing, to observe very distant galaxies in detail. The seven galaxies confirmed by Webb were first established as candidates for observation using data from the NASA/ESA Hubble Space Telescope’s Frontier Fields program. This makes them the earliest galaxies yet to be spectroscopically confirmed as part of a developing cluster. Webb reveals early-Universe prequel to huge galaxy cluster The seven galaxies highlighted in this image from the NASA/ESA/CSA Telescope have been confirmed to be at a distance that astronomers refer to as redshift 7.9, which correlates to 650 million years after the big bang. Brown dwarf binaries lie at the nexus of importance for understanding the formation mechanisms of these elusive objects, as they allow us to investigate whether the companions formed as stars or as planets in a disk around the primary. The system joins a small but growing sample of ultracool dwarf binaries with effective temperatures of a few hundreds of Kelvin. Under the assumption of a Keplerian orbit the period for this extreme binary is in the range of 5-9 years. Evolutionary models predict for that an age of 1-5 Gyr, the companion mass is about 4-12.5 Jupiter masses around the 7.5-20 Jupiter mass primary, corresponding to a companion-to-host mass fraction of q=0.61☐.05. ![]() At a distance of 10pc based on its Spitzer parallax, and assuming a random inclination distribution, the physical separation is approximately 1au. We employed an empirical point spread function binary model to identify the companion, located at a projected separation of 84 milliarcseconds, position angle of 295 degrees, and with contrast of 2.8 and 1.8 magnitudes in F150W and F480M, respectively. JWST/NIRCam discovery of the first Y+Y brown dwarf binary: WISE J033605.05−014350.4 We report the discovery of the first brown dwarf binary system with a Y dwarf primary, WISE J033605.05−014350.4, observed with NIRCam on JWST with the F150W and F480M filters.
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