91st Spring Meeting of the AAVSO: Paper Session Abstracts

For my advanced astronomy class, Physics 251, many of our laboratory exercises were co-operative assignments where each student contributed observations and data towards a common goal. Observations of supernovae and gamma-ray burst afterglow candidates were natural targets of opportunity. This past Spring Semester we observed SN2002ap and GRB020406. We observed the supernova with R and V filters and unfiltered several nights near maximum. We also observed the error region near GRB020406 and found some new, dim very cool infrared rich stars. The results from these observations will be reported. These targets provided excellent, applied examples of the material being covered in lecture.

Kirk S. Holtgrewe and D. T. Durig

We observed the cataclysmic variable star 1 RXP J113123+4322.5 while it was undergoing its recent outburst. We collected data using R and V filters, alternating the filters every two minutes. We obtained two to three hour-long data sets on two different nights. The light curve was analyzed using Mathematica. The period determined was near 95 minutes and there was some indication of a lower amplitude, higher frequency variation also.

Margarita Karovska

I'll present the latest results from our long-term study of Mira and its companion. These include the results from a recent HST study of the accretion processes in Mira AB interacting system showing significant unexpected variability in the UV.

I'll also describe the results from a recent mid-IR study of the dust environment in the system showing strong deviations from a spherical symmetry in the dust envelope of Mira.

Kevin B. Marvel

I will present images and analysis of millimeter observations of TX Cam and IK Tau. Specifically, I will show observations of the HCN distribution around these stars as well as discuss an unsuccessful search for methanol and CCH. Future millimeter arrays will greatly expand the knowledge of the chemistry in evolved star atmospheres.

Albert Zijlstra

Mira variables are among the brightest variable stars in the sky. Many have been known for over a century, and although they are normally found to be very stable, there are a number of intriguing exceptions. In this talk I will discuss several cases of Mira variables, which show evidence for period changes in the long-term light curves. Three different types of period instability are found: long-term continuous evolving periods, sudden large changes in an otherwise stable period, and fluctuating periods. The history and evolution of the star R Hya will be discussed. In the final part of the talk, a link is made between the Mira instabilities and the structures observed in their descendents, the planetary nebulae.

Bob Nelson

The author has written a Windows program that writes and reads files to interface with the Wilson-Devinney (star modeling) program. Some solutions to systems recently studied at the Mt John Observatory in New Zealand (WY Hor, TU Mus) will be presented.

Charles J Rodkey

One of the obstacles to ground based observing of GRB's is the short life of the afterglow. NASA's Swift satellite will reduce the notification time to seconds and increase the number of observed GRB's to approximately 150 per year. Amateurs with the right equipment can play a role in the follow-up. This Penn State led mission will have a multitude of research targets and opportunities.

Karen Jean Meech

In 2004 NASA will launch the Deep Impact Mission with the goal of exploring the interior of the nucleus of comet 9P/Tempel 1. On July 3, 2005 a 370-kilogram impactor will be released from the Deep Impact spacecraft colliding with the comet twenty-four hours later at 10.2 kilometers per second. Within a few hundred seconds the blow will excavate a crater equivalent in size to a football field and seven stories deep, while the flyby spacecraft takes imaging and spectroscopic data.

Comets are primordial remnants of the solar system's origin but whose surfaces are altered heavily since their formation. In order to understand the chemical and physical evidence from the early solar system, samples of pristine matter are necessary. The Deep Impact Mission impactor carves down to this pristine material. In this talk I will highlight the mission objectives in addition to the ground/space based observing plans and results to date.

Monday, July 1st, 4:20 pm - 6:30 pm

Messier Objects
      Diane Campbell, middle school science teacher
      Pebble Richwine, biology teacher
      Rosa Hemphill, chemistry teacher
      Timothy Slater, astronomy educator

High school teachers describe their humorous adventures in navigating the Hawaiian skies for the first time in search of the illusive Messier objects.

The challenge of locating variable stars with Dobsonian telescopes and producing a light curve to excite others will be discussed.

We have acquired use of Lowell Observatory 31" telescope as a test bed for long distance remote observing by high school students. The observing procedure involves target selection and development of night observing scripts. Single night of data can acquire up to 700 CCD images on 50-60 variable stars. We will discuss the results to date.

University of Chicago Stardial project images downloaded from the Internet were used to discover a Mira-type variable star in the constellation Aquila by a 2001 Hawaii TOPS high school student. The mentoring process by an AAVSO member contacted by the TOPS teacher and the resultant science fair project will be discussed.

We will discuss how 12 teachers and students developed photography skills in using 35 mm cameras attached to telescopes in order to take magnificent photographs of the moon. Besides sharing our successes and failures of developing techniques from the darkroom, we also used a barlow lens to magnify the moon surface. Using this enlargement of a small area, we applied geometry and trigonometry to calculate the depth of a crater using the length of its shadow.

Images collected by several groups with telescope projects having CCD cameras and photometers attached to laptop computers were used to produce a light curve of variable star V703 Scorpii.

The TOPS team, using a spectrograph and CCD camera attached to a laptop computer, will discuss its results of the solar and other spectral lines obtained.

Star Night VIII, is an on-going - educational partnership involving parents, community, and McKinley High School Complex; to provide aspects of astronomy in science education with students of 4th and 5th graders at Lanakila School, Honolulu, Hawaii. High School students participated as a service-learning project.

Teachers who take part in the University of Hawaii Institute for Astronomy Towards Other Planetary Systems (TOPS) Teacher Enhancement Workshop have the opportunity to make observations as part of their experience. The observations made by one teacher will be presented.

Tuesday, July 2nd, 9:00 am - 10:40 am

The new Optec SSP-4 infrared photometer will be available soon. The SSP-4 will enable small telescopes to observe at J and H (1.2 and 1.6 microns); a later version may also include K (2.2 microns). Most modern lists of standard stars are for larger telescopes and array detectors. We have combined both internal lists that were used for many years at major observatories for their single-channel work, as well as those lists available on the Web, to create a comprehensive bright-star standards list for calibration of the SSP-4 photometry.

The recent M74 Supernova event caused me to wonder about the enormous energy produced and the possibility of calculating the total visible light photon flux emanating from the event. With modern linear responsive CCD equipment able to quantitate the total photon captured per pixel, this is in fact possible. I have derived a formula and method that amateurs may utilize to calculate the total visible light flux from discrete luminous objects.

We have observed the ROTSE eclipsing binary, GSC 3515:0865 in V and B, and modeled the system using the Wilson-Devinney code. We find it to be a W UMa (type A) system. However, the degree of overcontact is slight and the data do not strongly reject a detached system.

Although OW Gem has been well observed during primary eclipse, the secondary eclipse has only a handful of data points. In 2002 the secondary will be observable in the early morning hours centered on October 19, 2002 and lasts thirty days.

3444 days of observations of UZ Serpentis are discussed. Numerous instances of standstill behavior are analyzed and the argument advanced for the reclassification of UZ Serpentis.

It is prevalent to assert that all of home astronomy is stargazing. Yet stargazing can be a terribly frustrating pursuit due to weather, lifestyle conflicts, social acceptance, luminous graffiti, crime and public nuisances, park closings and other factors. In many parts of the country, the failure to experience stargazing on a satisfying and consistent manner leads to abandonment of home astronomy.

New York City exploits earthly features of home astronomy, to the extent that loss of raw stargazing does not destroy the home astronomy culture. Several examples are presented of these, including, indoor meetings, cultural events at nonastronomy facilities, architectural astronomy motifs, star-themed coffee shops. In places where raw stargazing is interdicted, features such as those enjoyed in New York can rescue and enhance an otherwise ailing home astronomy culture.

Observers who are learning the art of sunspot counting and who recognize the importance of correctly estimating the numbers of groups present sometimes ask how much variation in the group total can be expected from day to day. For example, if one had decided that five groups were present on one day, could an estimate of seven groups on the following day be considered reasonable? Three groups? Five groups again?

With the objective of being able to provide observers with appropriate expectations, this paper presents the results of a brief statistical study of Solar Division estimates that was aimed at discovering the probabilities of changes of various amounts in the mean estimates of group numbers over successive days.

The results suggest that the probability of estimating the same numbers on successive days is equal to 0.255; of plus or minus one, 0.484; of plus or minus two, 0.160; of plus or minus three, 0.089; of plus or minus four, 0.012. No differences beyond four were found.

Tuesday, July 2nd, 11:00 am - 12:00 pm

We studied the period changes from 1888 to present in long period, Mira type, variable TY Cassiopeiae by combining 275 magnitudes and useful upper limits of brightness from the Harvard College Observatory plate collection with more than 1750 visual, photovisual, and CCD (V) magnitude measurements and upper limits from the AAVSO International Database. The star is shown to have decreased in period during the early years and then to have steadily increased. These changes appear to agree with the predictions of helium-flash models of Wood and Zarro (1981, ApJ 247, 252).

Dr. Ichinohe was born in 1872 in Aomori Prefecture, graduated from University of Tokyo. He studied under E. B. Frost, E. E. Barnard and S. W. Burnham during 1905-1907 at Yerkes Observatory where he measured the radial velocities of some spectroscopic binaries. He was a pioneer of astrophysics in Japan. He left about 12,000 visual observations of variable stars that were carried out in the USA and Japan. There remained several variable star charts that were given to Prof. Pickering on May 23, 1907.

After he returned to Japan, he was instructor at the University of Tokyo and astronomer at Tokyo Observatory. He insisted on the necessity of a large telescope in Japan. He planned Taiwan Observatory at the top of Mt. Yui (3997m above sea level.) At that time, Taiwan was occupied by Japan. The main telescope was 30 inch by Grubb's. The plan was not realized by financial problems.

After he retired from the University of Tokyo, he was the editor of the monthly magazine Gendai no Kagaku (Modern Science) which he founded on the model of Nature. He was also a pioneer of science journalism in Japan. He died in 1920 at the age of 48

Recent HST and X-ray photos of Eta Carinae reveal the "Great Eruption of 1843" and the lesser eruption of 1890. From debris gases on the outskirts beyond Eta's 1843 bipolar gaseous lobes, astrophysicists surmise an earlier outburst, ranging from 400 to 2000 years ago.

Eta Carinae is too far south for the early Chinese or other northern astronomers to have recorded this outburst. Researchers are looking for possible recordings by early southern hemisphere observers.

Pre-Incan artifacts recently discovered at Tiahuanaco by Bolivian archeologists may provide an answer. In the script and artwork on these artifacts are possible signs depicting the early outburst of Eta Carinae... the recordings of a star that suddenly brightened in their night sky.

In this experiment we used a percolation algorithm and some statistical tests to explore the following null hypothesis. That the current concept in High Energy Physics (HEP) that simultaneous clicks, with two or more detectors spaced a good distance apart (5 - 10 meters), are not coincidental random clicks, but are actual Cosmic Ray Showers from high energy protons impinging on our atmosphere.