Brett Morris

@brettmorr.is

14495 Followers 485 Following

Astronomer, software engineer. Supporting space telescopes, open science, and data access in astrophysics. Thrilled and haunted by dots on stars. http://brettmorr.is/ Posts my own, not my employer's.

Four severe weather alerts for Baltimore right now.
Americans with a “great deal of confidence” in the scientific community were equally represented among Democrats and Republicans until COVID.
Birthplaces by Rebecca Sheuerman
Red field-of-view outlines for the Roman Space Telescope's Wide Field Imager detectors near the galactic center, shown over a color composite of 2MASS imaging in the near-infrared.
Fig 7: Spot filling factors of HAT-P-11 as a function of time. Filling factors derived from rotational variability in Kepler and TESS light curves (using Equation 2 of Rackham et al. 2019) are compared with values inferred from multi-component spectral fits to HST G102 and G141 data. Independent chromospheric activity measurements (S-index values from the literature) are shown on the right axis. The Kepler era exhibits relatively high filling factors with substantial variability, whereas the TESS epochs indicate a transition to markedly lower spot coverage. Red vertical dotted lines mark the epochs of JWST observations
One year old golden retriever looking longingly into the distance.
Fig. 6. Geometric albedo model results, produced by sampling over the input parameter prior distributions (see Table 5) and using a scaling factor distribution to move the model away from chemical equilibrium. The wavelength-dependent albedos were then bandpass-integrated to produce the expected albedos in the TESS (orange) and CKC (blue) band. We find similar results to the chemical equilibrium model: temperature and pressure had no effect on the geometric albedo (so they are not shown here), and metallicity is the main driver. Due to increased parameter space from the relaxation of the chemical equilibrium constraint, the posteriors of TESS and CKC albedos are now wider and begin to overlap slightly. It is clear that the higher the metallicity, the lower the geometric albedo.
Albedo distributions measured with CoRoT, Kepler, and CHEOPS (blue), and with TESS (orange). Hierarchical Bayesian models suggest that both albedo distributions are compatible best described by Rayleigh distributions with consistent parameters in both groups.
Elementary school student Ruby Bridges escorted at school by a team of US Marshals to protect her from segregationists. Louisiana, 1960.
HD 140283 viewed in Aladin Lite with Pan-STARRS DR1 imaging. In the field of many stars,HD 140283 is bright, and relatively blue in this colormap.
Airport disclaimer that the airport does not agree with the partisan TSA video that is required to play thanks to dog murderer Kristi Noem
An expansive back-illuminated mural of JWST images of the Carina Nebula, with stars in blue and dust in gold.
A small koala stuffed toy holds onto a thin lamp stand.
solar flounce
NASA’s James Webb Space Telescope’s view of planetary nebula NGC 6072 in the near-infrared shows a complex scene of multiple outflows expanding out at different angles from a dying star at the center of the scene. There is one stretching from roughly 11 to 5 o’clock, another from 1 to 7 o’clock, and possibly a third from 12 to 6 o’clock. These outflows push gas toward the equatorial plane, forming a disk that appears to span from 9 to 3 o’clock. Astronomers suspect there is at least one other star interacting with the material cast off by the central dying star, creating the abnormal appearance of this planetary nebula. In this image, the red areas represent cool molecular gas, for example, molecular hydrogen.
Figure 1. Panel A: Light curve of the DWF030225.574- 545707.45 flare expressed as g magnitudes in excess of the quiescent stellar brightness. As noted in Webb et al. (2021), the lightcurve does not return to pre-flare brightness before the end of the observing period. Panel B: Raw d∥ measured on the images, relative to source position at t0. The weighted average d ∥ of 91 reference stars, weighted by the stars’ astrometric standard deviation across the entire time series, is shown as a grey line and the standard deviation of their relative position itself is shown as a filled region. Panel C: detrended d∥ of the flare star generated by subtracting the weighted average d∥ of the reference stars shown in Panel B. A 9-point rolling median is shown by the dashed black line. Panel D: Rolling median over an 9-point window of the detrended data shown in Panel C, and the time series used for subsequent analysis in this work.
Feels like temperature is 112 F, 44 C
Brett standing in front of a window overlooking the big clean room at NASA Goddard, where spacecraft are assembled. The Roman Space Telescope is behind Brett to the right.
Relative brightness maps of Antares over the course of a year, showing the changing brightness and shapes of convective cells in the stellar photosphere.
Purple haired woman in graffiti with white glasses and light bulbs and flamingos in her hair.
Interactive visualization tool for time-series spectra from the Olin Wilson Legacy Survey (OWLS). OWLS is monitoring stellar magnetic activity cycles with optical echelle spectra of FGKM stars with the ARC 3.5 m Telescope at Apache Point Observatory (APO).
Figure 7. Time series of S-indices for five targets with a range of spectral types. The top three panels show data from 1965 to 2024 for HD 78366 (F dwarf), HD 81809 (G dwarf), and the K-dwarf HD 26965, including historic MWO data (timespan in yellow) and newly obtained OWLS measurements (timespan in blue). We plot a curve on the G and K stars with three Lomb-Scargle (sinusoidal) terms, with periods ranging from 8 to 15 years. The OWLS S-indices from 2020-2024 for two M dwarfs GJ 388 B and GJ 494 are shown in the bottom row.
To celebrate NASA’s James Webb Space Telescope’s third year of highly productive science, astronomers used the telescope to scratch beyond the surface of the Cat’s Paw Nebula (NGC 6334), a massive, local star-forming region. This area is of great interest to scientists, having been subject to previous study by NASA’s Hubble and retired Spitzer space telescopes, as they seek to understand the multiple steps required for a turbulent molecular cloud to transition to stars. With its near-infrared capabilities and sharp resolution, the telescope “clawed” back a portion of a singular “toe bean,” revealing a subset of mini toe bean-reminiscent structures composed of gas, dust, and young stars. Webb’s view reveals a chaotic scene still in development: Massive young stars are carving away at nearby gas and dust, while their bright starlight is producing a bright nebulous glow represented in blue. This is only a chapter in the region’s larger story. The disruptive young stars, with their relatively short lifespans and luminosity, will eventually quench the local star formation process. The Cat’s Paw Nebula is located approximately 4,000 light-years away in the constellation Scorpius.
Alert on my phone says: “fire truck on fire” nearby.
Synthetic image of the star's shape, which was made with a stellar model that is consistent with the observations. The star is shaped like rugby ball, and it is an asymmetric brightness distribution. The star is white-hot near the pole, to the lower left, and blueish near the equator.
A line of peri peri peppers from ripe, dark red on the left, to deep green on the right.
Tree rings.
Cut trees stacked high.
Figure 3. Observed transit light curves of TOI-3884b (top to bottom: three transits observed with MuSCAT3 or MuSCAT4; left to right: g-, r-, i-, and z-band) and the corresponding best-fit models (black lines). The error bars in the datapoints are scaled to make reduced χ2 values equal to 1. To the right of each light curve, the spot distribution on the stellar surface at the corresponding epoch is shown, as modeled with fleck. The x mark in the figure shows the location of the stellar pole, the dotted lines show the stellar equator, and the regions inside dashed lines indicate the transit chord.
Coronal rain forms when hotter plasma in the Sun’s corona cools down and becomes denser. Like raindrops on Earth, coronal rain is pulled down to the surface by gravity. Because the plasma is electrically charged, it follows the magnetic field lines, which make huge arches/loops, instead of falling in a straight line. This image is a snapshot from a 23-minute time-lapse video which is comprised of the highest resolution images ever made of coronal rain. The scientists show in the paper that the strands can be narrower than 20 kilometers. This image was taken by the Goode Solar Telescope at Big Bear Solar Observatory using the new coronal adaptive optics system Cona. The image shows the hydrogen-alpha light emitted by the solar plasma. The image is artificially colorized, yet based on the color of hydrogen-alpha light, and darker color is brighter light. Credit: Schmidt et al./NJIT/NSO/AURA/NSF
NASA ADS can find 1,473 articles containing "in the era of JWST" in the title, abstract, or full text. And I say that's enough.
The High Sparrow prepares to announce Margery’s sentence in Game of Thrones.
This cluster of stars is known as Messier 15, and is located some 35,000 light-years away in the constellation of Pegasus (The Winged Horse). It is one of the oldest globular clusters known, with an age of around 12 billion years. This new image is made up of observations from Hubble's Wide Field Camera 3 and Advanced Camera for Surveys in the ultraviolet, infrared, and optical parts of the spectrum. (NASA, ESA)
In fiscal year 2019, the President asked for a -5% cut to NASA Science, but Congress passed an +11% increase into law instead.
"In an interview with LBC‘s Tom Swarbrick, the academic revealed that the chances of there being life on the faraway planet are at ’50/50’."
Dr Nikku Madhusudhan of the Institute of Astronomy at the University of Cambridge, who led the study, said of the findings: “Given everything we know about this planet, a hycean world with an ocean that is teeming with life is the scenario that best fits the data we have.”
AAS Action for Maryland Voters Let's meet to submit Congressional Appropriations Requests for Senators Van Hollen and Alsobrooks. Join on Zoom on Friday, April 18 at noon Eastern at https://bit.ly/3Y1cJq2. We will show you how to request funds for NASA, NSF, and DOE Office of Science. We will walk you through the process to submit an Appropriations Request to fund agencies that matter to you. Attendees from other states welcome!
"A ν look at the Sun: Probing the conditions of the solar core using 8B neutrinos," submission to arXiv by Melanie A. Zaidel and John F. Beacom.
33,000 jobs in the state of Maryland are supported by NASA.
"Although the budget would continue support for ongoing missions such as the Hubble Space Telescope and the James Webb Space Telescope, it would kill the much-anticipated Nancy Grace Roman Space Telescope, an observatory seen as on par with those two world-class instruments that is already fully assembled and on budget for a launch in two years."
Door label reads: “Data Closet.”
Me in a constellation bow tie in front of the Capitol Building.
Histogram of contributions to whoseline from 2017 to 2025, showing zero activity for seven years.
Demo video displaying a stellar spectrum with atomic spectral lines overlaid interactively.
Figure 10: Feasibility of detecting an Enceladus-like opposition effect signal in an exoplanet phase curve using both JWST and the future Habitable Worlds Observatory. The first panel shows the results when we use phase curves with an eclipse present and the second panel shows results without an eclipse present. The red line shows the FWHM value of the injected signal and the blue and orange points show the retrieved value, with 1-sigma errorbars. We find that, as expected, this signal is easier to detect in phase curves without an eclipse present, however this is still way beyond feasibility for both JWST and Habitable Worlds.
Figure 9: Simulated phase curve model of K2-141b, a super-Earth (red points, with green errorbars). The blue line shows the best fit of our opposition effect model. The noise here is at a level consistent with 10^3 JWST observations (top panel) and 10^5 observations (bottom panel).
Figure 5: Best fit models to one of one of Enceladus’ phase curves (filter 798 nm) for three different models: a pure single Henyey-Greenstein model with no additional opposition peak, shadow hiding model, and coherent backscattering model. Top panel shows the fits and the second panel shows the residuals of these best fits. It is clear that the model with no opposition peak is the worst fit to the data. The other two models produce, by eye, almost identical fits, which is expected since the functional forms are similar. However the residuals still show subtle differences. Using the LOO model selection statistic allows us to conclude that the coherent backscattering model is preferred by 7/12 of the phase curves, however not significantly. The corner plot showing the posteriors for the shadow hiding model are in Appendix A, Figure A.2.
Text from a proposal for TRAPPIST-1 observations at APO in 2016: "Just over one week ago, three new planets were announced in Gillon et al. (2016) that have the exoplanet community abuzz. TRAPPIST-1 b, c and d planets with radii within 16% the size of Earth’s, orbiting an M8 M = 0.08M star. The transits of these tiny planets would only impart very weak changes in the total flux of the host star if they orbited a Sun-like star, but the radius of the host star is more similar to Jupiter than to the Sun (R = 0.1R ). Therefore these planets likely have the largest known transit depths for planets of their size to date. Spectroscopy of the TRAPPIST-1 atmospheres will have to wait for JWST (Gillon et al., 2016), but these planets may be candidates for transit timing variations (TTVs) today. Periodic variations in the times of transit of exoplanets due to gravitational interactions between the planets in multi-planet systems can be used to measure the masses of planets and detect non-transiting planets (Agol et al., 2005; Ballard et al., 2011; Nesvorn´y et al., 2012). The two inner planets in the system have periods Pb = 1.510848 d and Pc = 2.421848 d, and assuming both planets have Ma,b = M⊕, the planets should have transit timing variations on the order of 0.5 minutes. If we can detect these TTVs, we can constrain on the masses of these likely rocky worlds."
Figure 3 of Petz & Kochanek (2025). Caption: "The Gaia DR3 𝑀𝐺 and 𝐵𝑃 − 𝑅𝑃 color-magnitude diagram of the final candidates divided into groups based on the dashed lines. The curves are solar metallicity 1 and 10 Gyr MIST isochrones. One type of light curve is shown in each group."
Color composite DSS image of the Andromeda Galaxy with an overlay of the Roman Space Telescope Wide Field Imager (WFI) footprint. Shown in the interactive data visualization and analysis tool `jdaviz`.
Gigantic container of Caffe Vita coffee beans, ready for bringing joy and solace.
Baby touching an electric guitar.
DSS image of HD 140283.
“Suspicious "Pile of Meat' Police were alerted to a questionable quantity of meat dropped near a dumpster.”