Search Publications
Properties of Flare Events on M Stars from LAMOST Spectral Survey Based on Kepler and TESS Light Curves
Han, Xianming L.; Misra, Prabhakar; Long, Liu +7 more
A catalog of M stars has been published from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope data release 7 (LAMOST DR7). We cross-matched the LAMOST M catalog with Kepler, Kepler 2 (K2) and Transiting Exoplanet Survey Satellite (TESS) surveys. We obtained the light curves from the Kepler and TESS surveys. We detected 20,047 flare ev…
Astrometric VLBI observations of H2O masers in an extreme OH/IR star candidate NSV 17351
Kurayama, Tomoharu; Honma, Mareki; Orosz, Gabor +14 more
The results of astrometric very long baseline interferometry (VLBI) observations toward an extreme OH/IR star candidate NSV 17351 are presented. Using the VERA (VLBI Exploration of Radio Astrometry) VLBI array , we observed 22 GHz H2O masers of NSV 17351 and derived an annual parallax of 0.247 ± 0.035 mas, which corresponds to a distanc…
The Long-term Monitoring Results of Insight-HXMT in the First 4 yr Galactic Plane Scanning Survey
Zhang, Shuang-Nan; Liu, Yuan; Wang, Chen +7 more
The first X-ray source catalog of the Insight-HXMT Galactic Plane (∣b∣ < 10°) Scanning Survey (GPSS) is presented based on the data accumulated from 2017 June to 2021 August. The 4 yr limit sensitivities at main energy bands can reach 8.2 × 10-12 erg s-1 cm2 (2-6 keV), 4.21 × 10-11 erg s-1 …
Spatial and temporal distribution of sinuous ridges in southeastern Terra Sabaea and the northern region of Hellas Planitia, Mars☆
Williams, Rebecca M. E.; Anderson, Ryan B.; Gullikson, Amber L.
Sinuous ridges are an important yet understudied component of Mars' hydrologic history. We have produced a map of sinuous ridges, valleys and channels, and tectonic ridges across southeastern Terra Sabaea and into northern Hellas Planitia (10°-45° S, 35°-80° E) using a CTX mosaic. Although we mapped different types of ridges and negative relief fe…
Evidence of an upper ionospheric electric field perturbation correlated with a gamma ray burst
Ubertini, Pietro; Bazzano, Angela; Zannoni, Ugo +68 more
Earth's atmosphere, whose ionization stability plays a fundamental role for the evolution and endurance of life, is exposed to the effect of cosmic explosions producing high energy Gamma-ray-bursts. Being able to abruptly increase the atmospheric ionization, they might deplete stratospheric ozone on a global scale. During the last decades, an aver…
Not So Fast, Not So Furious: Just Magnetic
Villaver, Eva; Landstreet, John D.; Bagnulo, Stefano
WD 0810-353 is a white dwarf within the 20 pc volume around the Sun. Using Gaia astrometric distance and proper motions, and a radial velocity derived from Gaia spectroscopy, it has been predicted that this star will pass within 1 pc of the solar system in about 30 kyr. However, WD 0810-353 has been also shown to host a magnetic field with a stren…
Rapidly Evolving Transients in Archival ZTF Public Alerts
Filippenko, Alexei V.; Yang, Yi; Li, Wenxiong +8 more
We search the archival Zwicky Transient Facility public survey for rapidly evolving transient (RET) candidates based on well-defined criteria between 2018 May and 2021 December. The search yielded 19 bona fide RET candidates, corresponding to a discovery rate of ~5.2 events per year. Even with a Galactic latitude cut of 20°, eight of the 19 events…
Confinedness of an X3.1-class Solar Flare Occurred in NOAA 12192: Analysis from Multi-instrument Observations
Guglielmino, S. L.; Zuccarello, F.; Ferrente, F. +1 more
The nonassociation of coronal mass ejections with high energetic flares is sparse. For this reason, the magnetic conditions required for the confinedness of major flares is a topic of active research. Using multi-instrument observations, we investigated the evolution and effects of confinedness in an X3.1 flare, which occurred in active region (AR…
The Maunakea Spectroscopic Explorer: Thousands of fibers, infinite possibilities
Sobeck, Jennifer; Barden, Samuel C.; Sheinis, Andrew
The Maunakea Spectroscopic Explorer (MSE) is a massively multiplexed spectroscopic survey facility that will replace the Canada–France–Hawai'i Telescope over the next two decades. This 12.5‑m telescope, with its 1.5 square degree field of view, will observe 18,000–20,000 astronomical targets in every pointing from 0.36 to 1.80 m at low/moderate re…
Optimizing machine learning methods to discover strong gravitational lenses in the deep lens survey
Jones, Tucker; Keerthi Vasan, G. C.; Sheng, Stephen +2 more
Machine learning models can greatly improve the search for strong gravitational lenses in imaging surveys by reducing the amount of human inspection required. In this work, we test the performance of supervised, semi-supervised, and unsupervised learning algorithms trained with the ResNetV2 neural network architecture on their ability to efficient…