A5052367756- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Astro and Planetary Science
- Astrophysical Phenomena and Observations
- Solar and Space Plasma Dynamics
- SAS software applications and methods
- Calibration and Measurement Techniques
- Geophysics and Gravity Measurements
- Adaptive optics and wavefront sensing
- History and Developments in Astronomy
- Inertial Sensor and Navigation
- Atmospheric Ozone and Climate
- Molecular Spectroscopy and Structure
- Color Science and Applications
- Geophysics and Sensor Technology
- Scientific Research and Discoveries
- Superconducting Materials and Applications
- Particle Detector Development and Performance
- Infrared Target Detection Methodologies
- Inorganic Fluorides and Related Compounds
- Global Health Care Issues
- Mechanics and Biomechanics Studies
East Tennessee State University
2012-2024
Southeastern Universities Research Association
2019-2023
University of Tasmania
2023
University of Oregon
1984-1987
University of New Mexico
1983
Kitt Peak National Observatory
1983
Rapidly rotating early-type stars with strong magnetic fields frequently show H$\alpha$ emission originating in Centrifugal Magnetospheres (CMs), circumstellar structures which centrifugal support due to magnetically enforced corotation of the confined plasma enables it accumulate high densities. It is not currently known whether CM escapes via Breakout (CB), or by an unidentified leakage mechanism. We have conducted first comprehensive examination properties all display CM-pattern emission....
We describe the remote facilities operated by Southeastern Association for Research in Astronomy (SARA), a consortium of colleges and universities US partnered with Lowell Observatory, Chilean National Telescope Allocation Committee, Instituto de Astrofisica Canarias. SARA observatories comprise 0.96m telescope at Kitt Peak, Arizona; 0.6m instrument on Cerro Tololo, Chile; 1m Jacobus Kapteyn Roque los Muchachos, La Palma, Spain. All are using standard VNC or Radmin protocols communicating...
The quasar 3C 279 was the target of an extensive multiwavelength monitoring campaign from 2006 January through April. An optical-IR-radio by Whole Earth Blazar Telescope (WEBT) collaboration organized around target-of-opportunity X-ray and soft γ-ray observations with Chandra INTEGRAL in mid-January, additional coverage RXTE Swift XRT. In this paper we focus on results WEBT campaign. source exhibited substantial variability optical flux spectral shape, a characteristic timescale few days....
view Abstract Citations (44) References (12) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Discovery of eclipse polarization in Algol. Kemp, J. C. ; Henson, G. D. Barbour, M. S. Kraus, Collins, W., II The first detection the stellar limb predicted by Chandrasekhar 1946 an eclipsing binary system is reported. Observations linear bright star Algol were made unifiltered light over a passband roughly 1000-5500 A, concentrated around times primary from December...
view Abstract Citations (55) References (19) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS SS 433: A 6 Year Photometric Record Kemp, J. C. ; Henson, G. D. Kraus, Carroll, L. Beardsley, I. S. Takagishi, K. Jugaku, Matsuoka, M. Leibowitz, E. Mazeh, T. Mendelson, H. homogeneous record of optical photoelectric photometric measurements this special object is presented, including over 800 observations on about 700 dates during 1979-1985, in the V band. complete...
view Abstract Citations (44) References (9) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Cygnus X-1 : optical variation on the 294 day X-ray period. Kemp, J. C. ; Barbour, M. S. Henson, G. D. Kraus, Nolt, I. Radostitz, V. Priedhorsky, W. Terrell, Walker, E. N. The recently discovered period has counterparts. A 10 yr B band photometric record shows synchronous changes of 0.01 mag amplitude, with minima coinciding minima. Stronger and weaker variations,...
We present high-precision optical polarimetric observations of the black hole X-ray binary Cygnus X-1 that span several cycles its 5.6-day orbital period. The week-long on two telescopes located in opposite hemispheres allowed us to track evolution polarization within one cycle with highest temporal resolution date. Using field stars, we determined interstellar source direction and subsequently intrinsic P int = 0.82%±0.15% a angle θ 155° ±5°. is aligned X-rays recently obtained Imaging...
view Abstract Citations (23) References (10) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Epsilon Aurigae: Polarization, Light Curves, and Geometry of the 1982--1984 Eclipse Kemp, J. C. ; Henson, G. D. Kraus, Beardsley, I. S. Carroll, L. Ake, T. B. Simon, Collins, W. Polarization light curves recent eclipse É› Aur are presented modeled, using a tilted, opaque secondary disk model atmosphere for F Ia primary star. That qualitatively explains striking...
Abstract We have monitored over a 10-year interval the light variations of five evolved stars with very large mid-infrared excesses. All objects appear to oxygen-rich or mixed and carbon-rich chemistries. They all vary in light: four small range ∼0.2 mag fifth larger ∼0.7 mag. Spectral types from G2 B0. Periodic pulsations are found for first time three cooler ones, IRAS 18075–0924 (123 days), 19207+2023 (96 20136+1309 (142 days). No significant periodicity is hotter but they on shorter...
view Abstract Citations (23) References (14) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The broad-band circular polarization of sunspots, 0.37-4.5 microns Kemp, J. C. ; Henson, G. D. Sunspot was examined with a sensitivity exceeding 3 millionths over the range 3700 A to 4.5 microns. Spectropolarimetric scans were performed an aperture 10 arcsec determine spatially averaged wavelength dependencies. slow scan also undertaken Ca II H and K lines. Passbands...
view Abstract Citations (15) References (10) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Discovery of Optical Circular Polarization in Lambda Andromedae Kemp, J. C. ; Henson, G. D. Kraus, Dunaway, M. H. Hall, S. Boyd, L. Genet, R. Guinan, E. F. Wacker, W. McCook, P. It is found that the RS CVn-type star has variable broad-band optical circular polarization, amplitude 0.002-0.004 percent, based on 59 nights' data during 1982, 1985, and 1986. The...
Aims: This paper extends previous studies in modeling time varying linear polarization due to axisymmetric magnetic fields rotating stars. We use the Hanle effect predict variations net line polarization, and geometric arguments generalize these results other mechanisms. Methods: Building on work of Lopez Ariste et al., we simple analytic models stars that are symmetric except for an field lightcurve effect. highlight effects variable as a function viewing inclination axis obliquity....
We present ten years of new photometric monitoring the light variability five evolved stars with strong mid-infrared emission from surrounding dust. Three are known carbon-rich proto-planetary nebulae (PPNe) F$-$G spectral types; nature other two was previously unknown. For three PPNe, we determine or refine pulsation periods IRAS 04296+3429 (71 days), 06530$-$0213 (80 and 23304+6147 (84 days). A secondary period found for each, a ratio P$_2$/P$_1$ 0.9. The variations small, 0.1-0.2 mag....
Polarization is a powerful tool for understanding stellar atmospheres and circumstellar environments. Mira semi-regular variable stars have been observed decades some are known to be polarimetrically variable, however, the V Canes Venatici displays an unusually large, unexplained amount of polarization. We present ten years optical polarization observations obtained with HPOL instrument, supplemented by published spanning total interval about forty CVn. find that CVn shows large variations...
Observations have been made of Beta Lyrae from 1.2 to 4.6 microns during the period 1977 1982 acquire reasonably complete light curves with much smaller errors than previous results. The clearly show how depth primary eclipse decreases relative secondary at longer wavelengths. A comparison Wilson's thick-disk model (fitted visual and UV data) is close for depths 3.5 micrometers, but not micrometers. At all wavelengths, observed shapes bottom eclipses a sharper turnaround that model.
We observed the short-period eclipsing system XY UMa (which displays RS CVn phenomena) on two nights in early 1982 at UBV bands. The light curves show both primary and secondary eclipses are asymmetrical that a distortion wave of small amplitude has minimum near phase 0.25. On night 1/31/82, we recorded flare-like episode 0.57 whose duration was about 30 minutes. total energy outburst 9% system's flux U, 4% B, 3% V.
Abstract Mira and semi-regular variable stars have been studied for centuries but continue to be enigmatic. One unsolved mystery is the presence of polarization from these stars. In particular, we present 40 years measurements prototype o Ceti V CVn find very different phenomena each star. The fraction position angle found small highly variable. On other hand, large variable, 2–7%, its approximately constant, suggesting a long-term asymmetric structure. We suggest number potential scenarios...
view Abstract Citations (17) References (15) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Variable Polarization and Activity in Arcturus Kemp, J. C. ; Henson, G. D. Kraus, Beardsley, I. S. Carroll, L. Duncan, K. High-sensitivity measurements of the blue light (B) polarization this bright, nearby star on 65 nights have led to discovery intrinsic variable polarization, with amplitude about 0.005 percent. There may be a period or semiperiod around 45 days,...
Cultural Astronomy sits at the intersection of our study universe and human experience, exploring how we observe stars, interpret their motions, incorporate them into perspectives nature reality. "Astronomy in Appalachia" is a new Planetarium show, developed for East Tennessee State University, that explores inherited experience night sky Appalachia can be used as part education, serve cross-cultural point connection. Using Earth's seasons an anchor, show highlights several Appalachian folk...
We examine over 160 archival H$\alpha$ spectra from the Ritter Observatory for interacting binary $\beta$~Lyr obtained between 1996 and 2000. The emission is characteristically double-peaked, but asymmetric, with an absorption feature that persistently blueshifted. Using a set of simplifying assumptions, phase varying line profiles are calculated formed entirely in Keplerian disk, separately off-center bipolar flow. However, dynamic spectrum data indicate blueshifted not always present, even...
The semi-regular variable star V Canum Venaticorum (V CVn) is well known for its unusual linear polarization position angle (PA). Decades of observing CVn reveal a nearly constant PA spanning hundreds pulsation cycles. This phenomenon has persisted through variability that varied by two magnitudes in optical brightness and the amplitude over 0.3 6.9%. Additionally, fraction varies inversely with brightness. paper presents measurements obtained three We find maximum does not always occur...