Search Publications
Observations of the Polarized Solar Corona During the Annular Eclipse of 14 October 2023
West, Matthew J.; Alzate, Nathalia; Seaton, Daniel B. +10 more
We present results of a dual eclipse expedition to observe the solar corona from two sites during the annular solar eclipse of 14 October 2023 using a novel coronagraph designed to be accessible for amateurs and students to build and deploy. The coronagraph (CATEcor) builds on the standardized eclipse observing equipment developed for the Citizen …
A Phenomenon Resembling Early Superhumps in a New SU UMa-type Dwarf Nova with a 2 hr Orbital Period
Garnavich, Peter; Littlefield, Colin; Szkody, Paula +4 more
We investigate K2BS5, an optical transient that we identified in Campaign 13 of the Kepler/K2 archives by the K2 Background Survey, and classify it as a new SU UMa-type dwarf nova. Using the light curve generated from Keplers long-cadence observation mode, we analyze the dwarf nova during quiescence and superoutburst. Following 20 days of quiescen…
Frequencies of Warm Debris Disks Based on Point Source Catalogs of Spitzer, WISE, and Gaia
Momose, Munetake; Mizuki, Toshiyuki; Aizawa, Masataka +1 more
More than a thousand warm debris disks have been detected as infrared excess at mid-infrared wavelengths, and their frequencies have been obtained for various spectral types of stars. However, the dependence of the frequencies on spectral type is still debated because the number of stars with significant and detectable infrared excess is limited. …
Whistler-mode waves in the tail of Mercury's magnetosphere: A numerical study
Henri, Pierre; Lavorenti, Federico; Califano, Francesco +1 more
Context. Mercury presents a highly dynamic, small magnetosphere in which magnetic reconnection plays a fundamental role. Aim. We aim to model the global characteristics of magnetic reconnection in the Hermean environment. In particular, we focus on waves observed during the third BepiColombo flyby. Method. In this work, we used two fully kinetic t…
Investigating the Linkage Between Spiral Trough Morphology and Cloud Coverage on the Martian North Polar Layered Deposits
Palucis, M. C.; Lutz, K. A.; Hawley, R. L.
The martian North Polar layered deposits (NPLD) are composed of alternating water-ice and dust-rich layers resulting from atmospheric deposition and are key to understanding Mars climate cycles. Within these deposits are spiral troughs whose migration affects deposition signals. To understand the relationship between NPLD stratigraphy and Martian …
Time evolution of X-ray bright points observed with NuSTAR
Krucker, Säm; White, Stephen M.; Grefenstette, Brian W. +5 more
We present analysis on two X-ray bright points observed over several hours during the recent solar minimum (2020 February 21 and 2020 September 12-13) with the Nuclear Spectroscopic Telescope Array (NuSTAR), a sensitive hard X-ray imaging spectrometer. This is so far the most detailed study of bright points in hard X-rays, emission which can be us…
LQAC-6: Sixth Release of the Large Quasar Astrometric Catalogue. A compilation of 2 073 099 objects with 1 739 187 Gaia DR3 counterparts
Barache, C.; Souchay, J.; Secrest, N. +1 more
Context. In addition to being objects of intense interest for cosmology and studies of the evolution of the universe, quasars are used to define quasi-inertial positions on the celestial sphere. Since its first publication in 2009, the purpose of the Large Quasar Astrometric Catalogue (LQAC) has been to provide the largest catalogue of bona fide q…
A statistical approach to polarimetric and photometric investigation of the intermediate-age open cluster NGC 1912
Biswas, Samrat; Medhi, Biman J.; Deb, Sushmita +3 more
This paper presents a comprehensive multiwavelength investigation of the intermediate-age open cluster NGC 1912. We identified 401 member stars for NGC 1912 using K-nearest neighbour and Gaussian Mixture Model machine learning techniques. The fundamental parameters determined for the cluster are metallicity (z) = 0.0141 $\pm$ 0.0006, log(age) = 8.…
Inversion for Inferring Solar Meridional Circulation: The Case with Constraints on Angular Momentum Transport inside the Sun
Sekii, Takashi; Hotta, Hideyuki; Hatta, Yoshiki
We have carried out inversions of travel times as measured by Gizon et al. to infer the internal profile of the solar meridional circulation (MC). A linear inverse problem has been solved by the regularized least-squares method with a constraint that the angular momentum (AM) transport by MC should be equatorward (HK21-type constraint). Our motiva…
The AH Pictoris Syndrome: Continuous Trains of Stunted Outbursts in Novalike Variables
Bruch, Albert
Novalike variables are a subgroup of cataclysmic variables (CVs) that—unlike dwarf novae—do not exhibit strong brightenings in their long-term light curves. Variations over timescales of weeks, months, or years are mostly restricted to irregular low-amplitude modulations. However, some of them occasionally suffer from so-called stunted outbursts, …