Search Publications
Detailed Imaging of Coronal Rays with the Parker Solar Probe
Vourlidas, Angelos; Poirier, Nicolas; Kouloumvakos, Athanasios +13 more
The Wide-field Imager for Solar PRobe (WISPR) obtained the first high-resolution images of coronal rays at heights below 15 R⊙ when the Parker Solar Probe (PSP) was located inside 0.25 au during the first encounter. We exploit these remarkable images to reveal the structure of coronal rays at scales that are not easily discernible in im…
Analysis of Cassini radio tracking data for the construction of INPOP19a: A new estimate of the Kuiper belt mass
Laskar, J.; Fienga, A.; Iess, L. +3 more
Context. Recent discoveries of new trans-Neptunian objects have greatly increased the attention by the scientific community to this relatively unknown region of the solar system. The current level of precision achieved in the description of planet orbits has transformed modern ephemerides in the most updated tools for studying the gravitational in…
Incoherent fast variability of X-ray obscurers. The case of NGC 3783
Kaastra, J. S.; Kriss, G. A.; Arav, N. +22 more
Context. Obscuration events caused by outflowing clumps or streams of high column density and low ionised gas, shown to absorb the X-ray continuum heavily, have been witnessed across a number of Seyfert galaxies.
Aims: We report on the X-ray spectral-timing analysis of the December 2016 obscuration event in NGC 3783, which was aimed at probin…
Abell 30 - A binary central star among the born-again planetary nebulae
Jones, David; Jacoby, George H.; Hillwig, Todd C.
Eight planetary nebulae have been identified as 'born-again', a class of object typified by knotty secondary ejecta having low masses (${\sim}10^{-4}$ M⊙) with nearly no hydrogen. Abell 30, the archetype of the class, also belongs to a small subset of planetary nebulae that exhibit extreme abundance discrepancy factors (where Abell 30 i…
The State of the Heliosphere Revealed by Limb-halo Coronal Mass Ejections in Solar Cycles 23 and 24
Gopalswamy, Nat; Akiyama, Sachiko; Yashiro, Seiji
We compare the properties of halo coronal mass ejections (CMEs) that originate close to the limb (within a central meridian distance range of 60°-∼90°) during solar cycles 23 and 24 to quantify the effect of the heliospheric state on CME properties. There are 44 and 38 limb halos in cycles 23 and 24, respectively. Normalized to the cycle-averaged …
New Beta Cephei Stars from the KELT Project
Pepper, Joshua; Stassun, Keivan G.; Siverd, Robert J. +9 more
We present the results of a search for Galactic β Cephei stars, which are massive pulsating stars with both pressure modes and mixed modes. Thus, these stars can serve as benchmarks for seismological studies of the interiors of massive stars. We conducted the search by performing a frequency analysis on the optical light curves of known O- and B-t…
Cool, Luminous, and Highly Variable Stars in the Magellanic Clouds from ASAS-SN: Implications for Thorne-Żytkow Objects and Super-asymptotic Giant Branch Stars
Drout, Maria R.; O'Grady, Anna J. G.; Kochanek, C. S. +9 more
Stars with unusual properties can provide a wealth of information about rare stages of stellar evolution and exotic physics. However, determining the true nature of peculiar stars is often difficult. In this work, we conduct a systematic search for cool and luminous stars in the Magellanic Clouds with extreme variability, motivated by the properti…
Data Lab-A community science platform
Nikutta, R.; Fitzpatrick, M.; Scott, A. +1 more
Data Lab is an open-access science platform developed and operated by the Community and Science Data Center (CSDC) at NSF's National Optical-Infrared Astronomy Research Laboratory (NOIRLab). It serves public photometric survey datasets, provides interactive and programmatic data access, and SQL/ADQL query capabilities via TAP. Users also receive g…
Searching for central stars of planetary nebulae in Gaia DR2
Walton, N. A.; Chornay, N.
Context. Accurate distance measurements are fundamental to the study of planetary nebulae (PNe) but they have long been elusive. The most accurate and model-independent distance measurements for galactic PNe come from the trigonometric parallaxes of their central stars, which were only available for a few tens of objects prior to the Gaia mission.…
Dynamics of Late-stage Reconnection in the 2017 September 10 Solar Flare
Judge, Philip G.; Long, David M.; Matthews, Sarah A. +2 more
In this multi-instrument paper, we search for evidence of sustained magnetic reconnection far beyond the impulsive phase of the X8.2-class solar flare on 2017 September 10. Using Hinode/EIS, CoMP, SDO/AIA, K-Cor, Hinode/XRT, RHESSI, and IRIS, we study the late-stage evolution of the flare dynamics and topology, comparing signatures of reconnection…