Author: Dr. Jessie Christiansen
Co-Authors:
Type: Oral
Title: A Preview of the first TESS Data Release
Abstract Description:
The NASA Transiting Exoplanet Survey Satellite (TESS) launched in April 2018, and is currently undertaking a two-year all-sky photometric time-series survey of bright stars searching for transiting extrasolar planets. In January 2019 the first four months of data will be publicly released, including images, light curves, and catalogues of astrophysically interesting transient events. These will include both planet candidates, many of which will need additional follow-up from the ground. This will be a large-scale effort that will benefit from and involve many amateur astronomers. I will explain the contents of the public data release, how to access it, and how you can get involved in helping TESS confirm upwards of 10,000 new exoplanets.
Author: Mr. Gary Walker
Co-Authors:
Type: Oral
Title: Is sCMOS Really sCMAS?
Abstract Description:
The world of Astro Imaging has seen several technology changes. The Author has experienced Tri-X film, push processing, Fuji 400, hyper sensitizing, CCD monochrome, colored filters, and now sCMOS. Many CCD chip manufacturers have shut down their factories--many to make space for new CMOS fab lines. Leveraging from the computer chip industry fabrication technology, CMOS chips offer small pixels, high speed, low noise, high dynamic range and most important, lower cost. While this works well for DSLR's, cell phone cameras, security cameras, and machine vision applications, how does this affect Astro Imaging? At the 2016 NEAIC, the word from vendors was that for the point and stare application of long exposures common to Astronomy, the CCD was still the detector of choice. The evolution of the CMOS technology may have closed the gap. The author investigates how CMOS can best be used for the point and stare applications that Astro Imagers need.
Author: Dr. Gerard Van Belle
Co-Authors:
Type: Oral
Title: Spatially and Temporally Resolving Mira Variables
Abstract Description:
In the past century, photometric and spectroscopic observations of stars has revolutionized our understanding of the structure and evolution of these fundamental building blocks of the universe. However, one of the largely untapped frontiers into investigating essential nature of stars remains with spatially resolved observations - can we observe these objects as more than just points of light? The exciting field of ultra-high-resolution observations with optical interferometry is opening that door, with remarkable results. In the particular case of Mira variables, we have targets that are present themselves not just as spatially interesting, but their temporally dynamic natures makes the time dimension also interesting. State-of-the-art results from some of the most modern observing equipment will be presented, significantly extended by the inclusion of AAVSO data, showing unique insights into the pulsation nature of Miras.
Author: Dr. Michael West
Co-Authors:
Type: Oral
Title: A Brief History of Astronomy on Mauna Kea
Abstract Description:
More than 17,000 nights have passed since the first telescopes arrived on Maunakea. In that time, the observatories on the summit of this ancient Hawaiian volcano have been at the forefront of astronomical research. Thousands of scientific papers have been published based on observations made with these telescopes, including the discovery of planets around other stars, the most distant known galaxies, and the accelerating expansion of the universe. This talk will give an overview of the past, present and future of astronomy on Maunakea.
Author: Gary Billings
Co-Authors:
Type: Oral
Title: Apsidal motion analysis of the eccentric eclipsing binary V1103 Cas
Abstract Description:
The Algol-type eclipsing binary system V1103 Cas was discovered by Otero et al. (2006), and identified as an eccentric system with period 6.1772 days. I observed it on multiple nights from 2012 to 2017, and found the primary and secondary eclipses to be of unequal depth and duration. The secondary eclipse is displaced from phase 0.5, and that displacement is slowly varying. Differential V-filtered lightcurves were modeled (using BinaryMaker3) to determine the eccentricity (0.27) and inclination (87.5 degrees) of the system. These parameters, and 10 times of minima, were used to determine the apsidal rotation period (748 years), using the method described by Lacy (1992). The presentation will include material showing how the eclipse widths and timing will vary through the apsidal period.
Author: Rodney Howe
Co-Authors:
Type: Oral
Title: Comparison of north-south hemisphere data from AAVSO visual observers and the SDO satellite computer generated Wolf numbers
Abstract Description:
Rolling correlations and rolling covariance analysis is used for two different type data submitted to the AAVSO solar database. In this paper we look at rolling correlations from 35 visual solar observers and their Wolf numbers for north and south solar hemispheres; and compare those data with SDO (Solar Dynamics Observatory) satellite Wolf numbers calculated from HMI CCD images of north-south magnetograms and visual intensity CCD images. http://hmi.stanford.edu The SDO computer generated group, sunspot and Wolf numbers from HMI images show symmetric volatility in the plots when compared to the AAVSO solar observers who count group, sunspot and Wolf numbers from observatories on Earth. Rolling correlation can be used to examine how correlative relationships between the two solar hemisphere Wolf numbers change over time. A value of 1 means both hemispheres are synchronized with each other. A value of -1 means that if one hemisphere’s Wolf numbers decline, the other hemisphere’s numbers rise. A correlation of zero means no correlation relationship exists.
Author: Dr. Arne A. Henden
Co-Authors:
Type: Oral
Title: APASS DR10 Has Arrived!
Abstract Description:
The AAVSO Photometric All-Sky Survey (APASS) has reached a new milestone with its Data Release 10 (DR10). Approximately 128 million stars have been calibrated from 7 < V < 17 and in passbands B,V,u',g',r',i',z'. This dataset has been made public on the AAVSO website.
APASS is designed to provide calibrated photometry everywhere in the sky and for nearly all CCD images. Much like the catalogs such as UCAC or GAIA do for astrometry, APASS gives the ability to photometrically calibrate your data without having to resort to all-sky photometry.
With DR10, the sky coverage is about 99%. There are still a few missing fields, primarily in the northern sky above declination 20 degrees. The upcoming DR11 will cover most of those fields, with about 200 new nights of data. It should be released very close to the time of the Fall meeting.
APASS is a volunteer-driven project. There are many opportunities for people at all skill levels to contribute to the project and help it reach its conclusion!
Author: Stanley A. Gorodenski
Co-Authors:
Type: Oral
Title: The Fun of Processing a Stellar Spectrum - the HARD WAY
Abstract Description:
Freeware exists for processing spectra: VSPEC, IRIS, ISIS, AUDELA, BASS, and MIDAS, to name some. One feature in common with all is that they can, to some extent, be viewed as black boxes, and they are limited to doing certain very specific functions. Not only may some users feel it would be too daunting to attempt to write computer programs to do some of the same things these packages do, many of them are limited to the extent a spectrum can be explored in a statistical and graphics sense. There are a huge number of gifted computer people in astronomy. This talk is directed toward those, like the author, who is not so gifted but found it very interesting and exciting to be able to write programs to explore a spectrum. Although there are many things one can do, such as computing equivalent width, computing radial velocity, and estimating a continuum, this talk will only focus on two things. It will show the fun of developing a Gaussian curve and using it to identify large deviations from an ideal Gaussian distribution at the pixel column level of a spectrum. It discusses some of the difficulties of doing a dark sky subtraction and it describes an exploratory method for doing one that, although it may or may not be better than the method these other packages use and actually is very computer intensive, it demonstrates what can be done if you can computer program and have a good statistical package with good programming capabilities.
Author: Joyce A. Guzik
Co-Authors: Jorge Garcia, Jason Jackiewicz
Type: Oral
Title: Discoveries for delta Scuti Variable Stars in the NASA Kepler 2 Mission
Abstract Description:
The NASA Kepler spacecraft launched nearly 10 years ago has been observing fields along the ecliptic plane for about 90 days each to detect planets and monitor stellar variability. We analyzed the light curves of thousands of main-sequence stars observed as part of the Kepler Guest Observer program. Here we summarize the statistics of discovery and properties of the pulsation amplitude spectra for about 250 delta Scuti variable stars found in Kepler 2 Campaigns 4 through 17. These stars are about twice as massive as the Sun, pulsating in many simultaneous radial and nonradial pulsation modes, with periods of about two hours. We discuss the potential and challenges for these stars of using pulsations to constrain stellar interior properties.
Author: Richard L. Berry
Co-Authors:
Type: Oral
Title: Conducting the Einstein Gravitational Deflection Experiment
Abstract Description:
In this presentation, I describe our experiment and results from the Einstein Eclipse Experiment carried out at Alpaca Meadows Observatory at the August 21, 2017 solar eclipse. For those intending in carry out a similar experiments at future solar eclipses, I describe the pitfalls we encountered and our successes in pre-eclipse preparation, image acquisition, data extraction, and data reduction. Thanks to PCC Sylvania's Dr. Toby Dittrich, students Andrew Jozwiak, Steve Pinkston, Abraham Salazar, Jacob Sharkansky, participant Jeremy Britton, donor David Vernier, and special thanks to Donald Bruns for his generous help and advice.
Author: Stephen Levine
Co-Authors: Arne Henden, Dirk Terrell, Doug Welch, Brian Kloppenborg
Type: Poster
Title: Solar System Objects and the AAVSO Photometric All-Sky Survey (APASS)
Abstract Description:
The AAVSO Photometric All-Sky Survey, data release 10 (APASS DR10) can be used for photometric calibration of observations of moving objects. Because APASS provides calibrated photometry over the whole sky, it makes it much simpler to tie together observations of objects, like asteroids and comets, that move appreciable distances over the time they are observed. Because the photometric standards are in each image, it will also be possible to recover photometry at the few percent level from non-photometric nights. In addition to providing calibration for new observations, the original APASS data comprise over 500,000 images, each 7.8 square degrees in size, taken over the course of more than nine years. We have searched those images for known Solar System bodies, and present the initial results of this search. For many of the objects found, we have simultaneous five color (B,V, g', r', and i') photometry. APASS provides photometric standards in at least five colors over the magnitude range 7 to 17, which makes it a good match for calibration for telescopes ranging from a few inches in size up to several meters.
Author: Jesse D'Shawn Harris
Co-Authors: Dr. Lucian Undreiu
Type: Poster
Title: Beta Cepheid and Mira Variable Stars: A Spectral Analysis
Abstract Description:
The purpose of this project is to investigate and compare the spectra of several variable stars, belonging to two classes, Beta Cephei and Mira, while trying to correlate our observations with the photometric survey maintained by AAVSO. For this study we have used a SBIG STT 8300 CCD camera, in conjunction with an LHIRES III Spectrograph, that was attached to a 16” Meade SCT telescope.
The short pulsation periods (0.1 – 0.3 days) of Beta Cephei variables enabled us to follow their evolution through the entire cycle of pulsation. The identification of H Balmer and neutral He lines, which are originating in the upper atmospheric layers, confirms the spectral class (early B-type). The Beta Cephei intricate dynamics of the pulsation mechanism is revealed by the changes in the width of strong spectral lines, as well as by the line doubling. BW Vulpelculae is of particular interest, due to its large amplitude of pulsation, reflected in the variability in its spectrum with progression through its period.
Mira variables are cool, red giants, pulsating slow (>100 days), while having large fluctuations in brightness. We collected and compared spectra of several Mira variables, identifying TiO and ZrO bands, typical for their spectral class (late M/S). Studying this class of variable stars is definitely relevant, as they offer us a way to see the future evolution of stars similar to our own Sun.
Author: Franz-Josef Hambsch
Co-Authors: C. S. Jeffery
Type: Oral
Title: New intense multiband photometric observations of the hot carbon star V348 Sgr
Abstract Description:
V348 Sgr is one of four hot carbon-rich and hydrogen-deficient stars. It is also a central star of a planetary nebula with a strong stellar wind, an infrared dust excess, and a circumstellar dust shell. Since July 2014, near daily multi-band photometric observations have been obtained at the Remote Observatory Atacama Desert (ROAD) close to San Pedro de Atacama, Chile. Strong variations of the brightness of V348 Sgr have been observed, ranging from magnitude 19 to 11.2 in V band. No clear periodicity is discernible in the data. The observed light curve shows much more variation and on a much shorter time scale than that of R CrB, the prototype hydrogen deficient, carbon- and helium rich star. The star becomes markedly redder during extinction phases as a consequence of obscuring dust. The particular challenge in this case is to understand what triggers the production of dust.
Author: Kristine Larsen
Co-Authors:
Type: Poster
Title: Variable Stars and Cultural Astronomy
Abstract Description:
Cultural astronomy encompasses the interdisciplinary, international, and multicultural fields of ethnoastronomy (the study of the astronomical knowledge and practices of current cultures) and archaeoastronomy (the study of the astronomical knowledge and practices of ancient cultures). Numerous universities across the US (and beyond) have developed cultural astronomy courses in recent decades in recognition of the sophisticated astronomical knowledge developed across the globe without the use of modern technology (i.e. the telescope or imaging technology). Cultural astronomy provides a lens through which to study of how individuals and cultures interacted with the heavens in personal and meaningful ways. While calendars, creation myths, celestially aligned structures, and navigation are usually the most common examples touted, what we now know to be variable stars have also played a role in the astronomical observations and mythology of numerous cultures. These include observations of supernovae, sunspots visible to the unaided eye, and possibly even Algol and other naked eye variables. Stellar variability has also been suggested as the reason why the Pleiades are widely known as a group of seven individuals (persons or animals) in mythologies from across the world despite the fact that only six are easily visible. This poster surveys these examples through a multicultural lens and suggests strategies for incorporating them in cultural astronomy courses and outreach programs.
Author: Michael Joner
Co-Authors:
Type: Oral
Title: Small Observatory Operations: 2018 Highlights from the West Mountain Observatory
Abstract Description:
The West Mountain Observatory (WMO) is an off-campus astronomical observatory operated by Brigham Young University. WMO is located about 23 km southwest of the main BYU campus in Provo, Utah at an elevation of 2120 m. Observations are done for a variety of student and faculty projects using the three small telescopes (0.3 m, 0.5 m, and 0.9 m) housed at WMO. I will present a summary of recent upgrades and improvements at WMO along with observational highlights from 2018 that include targets ranging from solar system objects out to active galaxies with a lot of ground to cover in between.
Author: Ariana Hofelmann
Co-Authors: Brian Hill
Type: Oral
Title: Stepping Stones to TFOP: Experience of the Saint Mary's College Geissberger Observatory
Abstract Description:
We upgraded our college's Meade 0.4m telescope, including its software, mount and imaging train, in order to perform exoplanet photometry. We used a variety of resources, beginning with Dennis Conti's Exoplanet CHOICE course. We will summarize the data-taking processes and analysis software typically used for this type of photometry. After having been accepted into the TESS Followup Observing Program Sub Group 1 (TFOP SG1), we have been going through a process of imaging and submitting false positives that conform to their data submission requirements. We hope our experience and the encouragement of the TFOP program leaders will inspire other AAVSO members to go through similar steps.
Author: Lew Cook
Co-Authors: Enrique de Miguel, Geoff Stone, Gary E. Walker
Type: Oral
Title: The Faint Cataclysmic Variable V677 Andromeda
Abstract Description:
More than 5000 CCD/CMOS photometric observations of the cataclysmic variable V677 Andromeda were made in the years 2015, 2016 and 2018 and the light curves are compared. The light curves are found to differ slightly from year-to-year for an unknown reason and there is also a dependence on the level of activity in this binary pair. In its active state, the light curve exhibits a double humped shape, while in the declining state, the double hump in large part disappears. Our sparse photometry in this state nonetheless strongly suggests it is replaced by a single-hump shaped light curve. The star was too faint for us to observe in the inactive state except for stacked images covering entire cycles. A refined estimate of the period from our 2018 data was found to be 105 minutes, 18.6 seconds, however it is not firmly established if this is the orbital period or a “superhump” period.
Author: Ken Steiner
Co-Authors:
Type: Oral
Title: Cold War Spy in the Sky now Provides an Eye on the Cosmos
Abstract Description:
The 12 meter satellite communications dish at Pisgah Astronomical Research Institute (PARI) was updated and converted from an electronic spy role to an astronomical radio telescope after being dormant for 20 years. The presentation will compare radio and optical telescopes and look at the cold war mission of this instrument when PARI was formerly a Department of Defense facility (Rosman Station).
After the dormancy of 20 years the story of the update and conversion to a radio telescope will be illustrated along with the current student involvement at PARI with the newly commissioned instrument. Finally we will look at the variable star observation on August 21, 2017, to our knowledge the first time a solar eclipse was observed by a large radio telescope.
Author: Michael Nicholas
Co-Authors:
Type: Poster
Title: Bright Star Monitor Network
Abstract Description:
The AAVSO Bright Star Monitor telescopes are a subset of the larger AAVSOnet network located at sites around the world. Each site is equipped with a a small telescope, a high grade astronomical camera and standard photometric filters. They are operated robotically, and are locally supported by AAVSO member volunteers. Each telescope is capable of performing precise CCD photometric measurements on the sky’s relatively bright stars; those in the range of 3.0 to 13.0 V magnitudes. It is available free to all AAVSO members.
Author: Isobel Snellenberger
Co-Authors: Adam Kline
Type: Poster
Title: Camera characterization and first observation after upgrade of Feder observatory
Abstract Description:
We prepared the Paul P. Feder Observatory at the Minnesota State University Moorhead Regional Science Center to observe exoplanet transits after recent upgrades of the camera and control system. We characterized the camera by measuring linearity, gain, read noise, and dark current. We also discuss how we minimize tracking error without a guide camera. We observed a transit of the exoplanet Kelt 16b, the first exoplanet transit observed with the new system. The goal is to observe exoplanet candidates identified by the Transiting Exoplanet Survey Satellite (TESS).
Author: Tom Alessi
Co-Authors: Craig Richardson
Type: Oral
Title: Charitable Giving Strategies to fit any Donor
Abstract Description:
Everyone can create a legacy. There are many different methods to make gifts to charities. Some are financial transactions, some provide various tax benefits. In general, the Internal Revenue Code (IRS) can provide a variety of tax benefits but adherence to the strict rules is important.
The presentation will cover a quick overview of possible gifting strategies, so you have a high-level understanding of each and how they can be used to benefit the American Association of Variable Star Observers (AAVSO), either now or in the future, and the benefits available to you as a donor to the organization. Clearly, everyone who desires to can create a lasting legacy through a gift to the AAVSO .