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The Companion Mass Distribution of Post Common Envelope Hot Subdwarf Binaries: Evidence for Boosted and Disrupted Magnetic Braking?
El-Badry, Kareem; Nagarajan, Pranav; van Roestel, Jan +6 more
We measure the mass distribution of main-sequence (MS) companions to hot subdwarf B stars (sdBs) in post-common envelope binaries (PCEBs). We carried out a spectroscopic survey of 14 eclipsing systems ("HW Vir binaries") with orbital periods of 3.8 < Porb < 12 hr, resulting in a well-understood selection function and a near-comple…
A Suite of Classical Cepheids Tied to the Binary Cluster Berkeley 58 and NGC 7790
Majaess, Daniel; Turner, David G.
The classical Cepheids CE Cas A, CE Cas B, CF Cas, and CG Cas are likely members of the binary open cluster comprising NGC 7790 and Berkeley 58. The clusters are of comparable age and in close proximity, as deduced from differentially dereddened UuB P BVGR P photometry, and Cepheid period-age relations. Gaia DR3 astrometr…
JWST's PEARLS: Improved Flux Calibration for NIRCam
Grogin, Norman A.; Hathi, Nimish P.; Koekemoer, Anton M. +23 more
The Prime Extragalactic Areas for Reionization and Lensing Science, a James Webb Space Telescope (JWST) GTO program, obtained a set of unique NIRCam observations that have enabled us to significantly improve the default photometric calibration across both NIRCam modules. The observations consisted of three epochs of 4-band (F150W, F200W, F356W, an…
Toward Exoplanet Transit Spectroscopy Using JWST/MIRI's Medium Resolution Spectrometer
Deming, Drake; Lustig-Yaeger, Jacob; Fu, Guangwei +9 more
The Mid-Infrared Instrument Medium Resolution Spectrometer (the MRS) on JWST has potentially important advantages for transit and eclipse spectroscopy of exoplanets, including lack of saturation for bright host stars, wavelength span to longward of 20 µm, and JWST's highest spectral resolving power. We here test the performance of the MRS for time…
Astrometry as a Tool for Discovering and Weighing Faint Companions to Nearby Stars
Brandt, Timothy D.
This tutorial covers the use of absolute astrometry, in particular from the combination of the Hipparcos and Gaia missions, to identify faint companions to nearby stars and to measure the masses and orbits of those companions. Absolute astrometry has been used with increasing success to discover new planets and brown dwarfs and to measure masses a…
Near-Earth Object Observations using Synthetic Tracking
Zhai, Chengxing; Shao, Michael; Choi, Philip +5 more
Synthetic tracking (ST) has emerged as a potent technique for observing fast-moving near-Earth objects (NEOs), offering enhanced detection sensitivity and astrometric accuracy by avoiding trailing loss. This approach also empowers small telescopes to use prolonged integration times to achieve high sensitivity for NEO surveys and follow-up observat…
Likelihood-based Jump Detection and Cosmic Ray Rejection for Detectors Read Out Up-the-ramp
Brandt, Timothy D.
This paper implements likelihood-based jump detection for detectors read out up-the-ramp, using the entire set of reads to compute likelihoods. The approach compares the χ 2 value of a fit with and without a jump for every possible jump location. I show that this approach can be substantially more sensitive than one that only uses the d…
Database Design for SpExoDisks: A Database and Web Portal for Spectra of Exoplanet-forming Disks
Banzatti, Andrea; Hinkel, Natalie R.; Wheeler, Caleb H.
Data access—or the availability of new and archival data for use by the larger community—is key for scientific advancement. How data is presented, searched, and formatted determines accessibility and it can be difficult to find a solution that fits the needs of a given subdiscipline. We present a generalized roadmap for developing a specialty astr…
The Valuable Long-period Cluster Cepheid KQ Scorpii and other Calibration Candidates
Minniti, Dante; Majaess, Daniel; Turner, David G. +2 more
The classical Cepheid KQ Sco is a valuable anchor for the distance scale because of its long pulsation period ($28^{\rm d}.7$) and evidence implying membership in the open cluster UBC 1558. Analyses tied to Gaia DR3 astrometry, photometry, spectroscopy, radial velocities, and 2MASS-VVV photometry indicate a common distance of $2.15\pm0.15$ kpc (\c…
Star Image Centering with Deep Learning. II. HST/WFPC2 Full Field of View
Casetti-Dinescu, Dana I.; Girard, Terrence M.; Baena-Gallé, Roberto +2 more
We present an expanded and improved deep-learning (DL) methodology for determining centers of star images on Hubble Space Telescope/Wide-Field Planetary Camera 2 (WFPC2) exposures. Previously, we demonstrated that our DL model can eliminate the pixel-phase bias otherwise present in these undersampled images; however that analysis was limited to th…