Search Publications
New precise positions in 2013-2019 and a catalog of ground-based astrometric observations of 11 Neptunian satellites (1847-2019) based on Gaia-DR2
Ren, Shulin; Fu, Yanning; Yuan, Ye +1 more
Context. Developing high-precision ephemerides for Neptunian satellites requires not only the continuation of observing campaigns but also the collection and improvement of existing observations. So far, no complete catalogs of observations of Neptunian satellites are available.
Aims: We aim to provide new, precise positions, and to compile a…
Over-expansion of a coronal mass ejection generates sub-Alfvénic plasma conditions in the solar wind at Earth
Schmieder, B.; Poedts, S.; Démoulin, P. +4 more
Context. From May 24-25, 2002, four spacecraft located in the solar wind at about 1 astronomical unit (au) measured plasma densities one to two orders of magnitude lower than usual. The density was so low that the flow became sub-Alfvénic for four hours, and the Alfvén Mach number was as low as 0.4. Consequently, the Earth lost its bow shock, and …
Ultrafaint [C II] Emission in a Redshift = 2 Gravitationally Lensed Metal-poor Dwarf Galaxy
Walter, F.; van der Wel, A.; Groves, B. +13 more
Extreme emission-line galaxies (EELGs) at redshift z = 1-2 provide a unique view of metal-poor, starburst sources that are the likely drivers of the cosmic reionization at z ≥ 6. However, the molecular gas reservoirs of EELGs—the fuel for their intense star formation—remain beyond the reach of current facilities. We present ALMA [C II] and PdBI CO…
Boyajian's Star B: The Co-moving Companion to KIC 8462852 A
Huber, Daniel; Dupuy, Trent J.; Kraus, Adam L. +2 more
The light curve of KIC 8462852, aka Boyajian's Star, undergoes deep dips the origin of which remains unclear. A faint star ≈2″ to the east was discovered in Keck/NIRC2 imaging in Boyajian et al., but its status as a binary, and possible contribution to the observed variability, was unclear. Here, we use three epochs of Keck/NIRC2 imaging, spanning…
Use of the DBM Model to the Predict of Arrival of Coronal Mass Ejections to the Earth
Kaportseva, K. B.; Shugay, Yu. S.
This paper analyzes the results of modeling coronal mass ejection (CME) propagation in 2010-2011 obtained using input data from different sources: CME catalogs SEEDS and CACTus, and predictions of the velocity of quasi-stationary solar wind fluxes, as an environment, through which CMEs propagate. As the model of quasi-stationary solar wind fluxes,…
Plasma Upflows Induced by Magnetic Reconnection Above an Eruptive Flux Rope
Long, David M.; Janvier, Miho; Brooks, David H. +6 more
One of the major discoveries of Hinode's Extreme-ultraviolet Imaging Spectrometer (EIS) is the presence of upflows at the edges of active regions. As active regions are magnetically connected to the large-scale field of the corona, these upflows are a likely contributor to the global mass cycle in the corona. Here we examine the driving mechanism(…
Spectroscopic Redshift Determination for a Sample of Distant Quasars Detected by the SRG Observatory Based on RTT-150 Observations. II
Irtuganov, E. N.; Bikmaev, I. F.; Gilfanov, M. R. +16 more
Results of the spectroscopic observations at the 1.5-m Russian-Turkish telescope for another group of 12 X-ray sources discovered by the eROSITA telescope onboard the SRG space observatory and identified by the SRGz machine learning system as candidates for distant X-ray quasars are presented. Ten objects have been confirmed as quasars at redshift…
Signature and escape of highly fractionated plasma in an active region
Brooks, David H.; Yardley, Stephanie L.
Accurate forecasting of space weather requires knowledge of the source regions where solar energetic particles (SEP) and eruptive events originate. Recent work has linked several major SEP events in 2014, January, to specific features in the host active region (AR 11944). In particular, plasma composition measurements in and around the footpoints …
A Comprehensive Astrometric Calibration of HST's WFPC2. I. Distortion Mapping
Anderson, Jay; Horch, Elliott P.; Kozhurina-Platais, Vera +3 more
Wide field planetary camera 2 (WFPC2) exposures are already some 20 years older than Gaia epoch observations, or future James Webb Space Telescope observations. As such, they offer an unprecedented time baseline for high-precision proper-motion studies, provided the full astrometric potential of these exposures is reached. We have started such a p…
Tracking Advanced Planetary Systems (TAPAS) with HARPS-N. VII. Elder suns with low-mass companions
Adamów, M.; Maciejewski, G.; Villaver, E. +3 more
Context. We present the current status of and new results from our search for exoplanets in a sample of solar-mass evolved stars observed with the HARPS-N and the 3.6 m Telescopio Nazionale Galileo (TNG), and the High-Resolution Spectrograph (HRS) and the 9.2 m Hobby-Eberly Telescope (HET).
Aims: The aim of this project is to detect and chara…