Search Publications
Eta Carinae: The Dissipating Occulter Is an Extended Structure
Hamaguchi, Kenji; Corcoran, Michael F.; Moffat, Anthony F. J. +11 more
Previous Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph (STIS) longslit observations of Eta Carinae (η Car) identified numerous absorption features in both the stellar spectrum, and in the adjacent nebular spectra, along our line of sight (LOS). The absorption features became temporarily stronger when the ionizing far-ultraviole…
Far-infrared polarization of the supernova remnant Cassiopeia A with SOFIA HAWC +
Hoang, Thiem; Kirchschlager, Florian; Tram, Le Ngoc +8 more
We present polarization observations of the young supernova remnant (SNR) Cas A using the High-resolution Airborne Wideband Camera-Plus (HAWC +) instrument onboard the Stratospheric Observatory for Infrared Astronomy (SOFIA). The polarization map at 154 $\mu$m reveals dust grains with strong polarization fractions (5-30 per cent), supporting previ…
Constraining Young Hot Jupiter Occurrence Rate in Stellar Associations Using 2-min Cadence TESS Data
Ma, Bo; Fang, Yuanqing; Chen, Chen +1 more
The characterization of young planet distribution is essential for our understanding of the early evolution of exoplanets. Here we conduct a systematic search for young planets from young open clusters and associations using the 2-min cadence TESS survey data. We obtain TESS light curves for a total of 1075 young stars, which are selected with the…
Estimating Ion Temperatures at the Polar Coronal Hole Boundary
Landi, Enrico; Zhu, Yingjie; Szente, Judit
The temperatures of the heavy ions (T i ) in the solar corona provide critical information about the heating mechanism of the million-degree corona. However, the measurement of T i is usually challenging due to the nonthermal motion, instrumental limitations, and optically thin nature of the coronal emissions. We present t…
Orbital parallax of binary systems compared to Gaia DR3 and the parallax zero-point offset at bright magnitudes
Groenewegen, M. A. T.
Multiple systems for which the astrometric and spectroscopic orbit are known offer the unique possibility of determining the distance to these systems directly without any assumptions. They are therefore ideal objects for a comparison of Gaia data release 3 (GDR3) parallax data, especially since GDR3 presents the results of the non-single star (NS…
CSS1603+19: a low-mass polar near the cataclysmic variable period minimum
Thorstensen, John R.; Zakamska, Nadia L.; Hwang, Hsiang-Chih +1 more
CSS1603+19 is a cataclysmic variable (CV) with an orbital period of 81.96 min, near the minimal period of CVs. It is unusual in having a strong mid-infrared excess inconsistent with thermal emission from a brown dwarf companion. Here, we present time-resolved multiwavelength observations of this system. WISE photometry indicates that the mid-infra…
Probing general relativity in galactic scales at z 0.3
Chies-Santos, Ana L.; Furlanetto, Cristina; Melo-Carneiro, Carlos R.
General Relativity (GR) has been successfully tested mainly at Solar system scales; however, galaxy-scale tests have become popular in the last few decades. In this work, we investigate the ηPPN parameter, which is commonly defined by the ratio of two scalar potentials that appears in the cosmological linearly perturbed metric. Under th…
A Review of Instrument Techniques to Measure Magnetospheric Cold Electrons and Ions
Reisenfeld, Daniel B.; Maldonado, Carlos A.; Resendiz Lira, Pedro A. +3 more
A review of the instruments and techniques to directly measure the full distributions of the cold-ion and cold-electron populations in the magnetosphere is presented. Relatively few studies have focused on the cold plasma populations of the magnetosphere due to difficulties associated with obtaining measurements. The cold particle populations are …
Permafrost molards as an analogue for ejecta-ice interactions at Hale Crater, Mars
Lucas, Antoine; Conway, Susan; Noblet, Axel +7 more
When the Hale impact crater penetrated the martian cryosphere 1Ga, landforms indicating post-impact volatile mobilisation were generated. We have found landforms in the ejecta blanket of Hale Crater similar to 'permafrost molards' found in periglacial environments on Earth, and probably related to the past or present presence of volatiles at/near …
Reddening-Free Q Parameters to Classify B-Type Stars with Emission Lines
Aidelman, Yael; Cidale, Lydia Sonia
The emission-line B-type stars constitute a heterogeneous group. Many of these stars show similar optical spectroscopic features and color indices, making it difficult to classify them adequately by means of photometric and spectroscopic techniques. Thus, it is relevant to deal with appropriate classification criteria to avoid as many selection ef…