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These images of comet Hale-Bopp were aquired in the early morning of March 13th, with the DA 8" refractor mounted with the SBIG ST-6 CCD. Each image highlights different size structures near the comet's nucleus. The base image is a composite of thirteen four second V-band images, which have been shifted and co-added to increase the signal-to-noise ratio, while avoiding saturation of the central coma. This base image has been convolved with different size gaussian profiles (to limit the smallest visible structure size in each image) and then laplacian filtered to enhance the small scale structures. The arc structures near the nucleus are likely to be dust shells ejected by an active jet on the comet's surface, modulated by the comet's rotation. The direction of motion of the comet is approximately diagonal in these images (from the top right to the bottom left); this was inferred from a trailed star image visible on the original unfiltered composite image. The apparent ability of even the 8" refractor to illustrate such features (which were reported in the IAU circulars only a few days before this image was taken) is a testament to the truly spectacular nature of this comet. Currently, there are plans to image Hale-Bopp in a similiar manner over several days time, in an attempt to detect motion and evolution of these dramatic features. Hale-Bopp is currently circumpolar at Toronto's latitude, and is bright enough to be readily detected even in the daylight sky; the only limitation now is the weather!
The spectrum of comet Hale-Bopp shown on the cover was acquired on February 9th, using the DDO 74"
telescope. The obvious emission feature at 5165 Angstroms is the head of the
Swan C2 band - this is often the dominant emission feature of comet spectra.
The absorption features just blue-ward of this are absorption lines from the
solar spectrum.
Last week, an open meeting was held to discuss the direction for changes at the Dunlap Observatory. A lively discussion generated lots of new ideas and revived some old, forgotten ones. One of the themes which emerged was one of more integration with the department, through more undergraduate and graduate exposure, as well as increased public awareness through more public. Students and faculty alike seemed enthusiastic about the prospects of using the DDO in new and exciting ways.
One of the purposes of reviving the DOINGS and modifying the name to give it a more inclusive identity is to facilitate integration of the various elements of the department. With centres in Scarborough, Erindale, St. George and DDO, we often don't see each other often enough or long enough to catch up on our "doings." The new DOINGS is much easier and less expensive to produce, and has the potential of enhancing a sense of community. The response from outside has been great, so it seems that putting the DOINGS on the WWW was a good move.
To make the DOINGS really work, we need input from a broad
spectrum of the community: students, faculty, staff, and alumnae.
It only takes a few minutes to submit a paragraph to COMINGS AND
GOINGS or to write a few paragraphs about some interesting
phenomenon or experience, whether or not it is astronomical. We
would especially like to see more input from staff. A closer
knit community can more easily handle pressures from outside.
Lillian Lanca has joined the office staff at DA on February 10,
replacing Nella who is now on maternity leave. Welcome, Lillian!
Bob Garrison will be observing with Chris Corbally for ten nights
starting 23 April, using the new Vatican Advanced Technology
Telescope (VATT) on Mt. Graham near Tucson.
John Percy participated in a special symposium at Yale University in
honour of the 90th birthday of Dorrit Hoffleit. For those of you who
do not know who she is, suffice it to say that she was the second
winner (after Carl Sagan) of the American Astronomical Society's
Annenberg Award for outstanding and sustained contributions to
astronomy education. Among many other things, she was Director,
for two decades, of the Maria Mitchell Observatory on Nantucket,
where she developed a summer program to introduce undergraduates
to astronomical research and education. For most of the two decades,
the program was targeted to women, and many outstanding astronomers
(including Andrea Dupree, Nancy Evans, and Gretchen Harris) got their
start in astronomy at MMO. Dorrit is also the editor of several
important catalogues, including the Bright Star Catalogue, and has
made contributions to research in variable stars, stellar spectroscopy,
meteor science, and the history of astronomy. She remains cheerfully
and productively active in "retirement" at Yale.
Phil Kronberg was an invited speaker at the NASA Goddard Space
Flight Center on May 9th 1996, and also at the International
Symposium on Extremely High Energy Cosmic Rays in Tokyo Japan in
September 1996.
Bob Garrison has been spending a few days per quarter at Yerkes
Observatory helping to sort through the rich and varied legacy of
W.W. Morgan who died in 1994. A memorial room has been
established at Yerkes to display some of Morgan's favorite books
and artwork. A large collection of professional and personal
memorabilia, including a few hundred personal notebooks, is being
stored in the archives of the University of Chicago, where Morgan
spent 68 of his 88 years.
Phil Kronberg gave the weekly colloquium at the Aspen Institute of Physics on
August 20th 1996, entitled "Extragalactic Magnetic Fields". He was a
member of the advisory committee for the Aspen Workshop on Cosmological
Magnetic Fields.
Simon Lilly was in town for the week of 17 March, visiting from
Cambridge University, where he is on Research Leave this year.
Phil Kronberg was a Winter 1997 Series colloquium seaker at the
Case Western Reserve University Physics Department (Jan 16th 1997),
and is the Physics Department colloquium speaker at the University of
Michigan on May 5th 1997. Topic: "Magnetic Fields Outside of
Galaxies: Recent Measurements and Near-Future Prospects".
And lots of other little goodies. So don't say "there's nothing new at
the Science Centre" or "the Science Centre is just for kids".
Last fall George Bryant, a travel writer for The Toronto Star, related the tale of the good ship Warrimoo, which in late-1899 was en route from Vancouver to Australia. Her captain, no doubt not without forethought, found the ship approaching the intersection of the international dateline and the equator close to midnight on December 31, and cut the engines just when he claimed to have reached this point at that critical time. (Let's not spoil the fun by asking the uncertainty in the navigation; suffice to say he wasn't using the GPS system.) Since the ship had been travelling in a south-westerly direction, the passengers were in a remarkable position: Walking from the stern to the bow they went from near-mid-winter to near-mid-summer, from the northern hemisphere to the southern hemisphere, from a Monday to the previous Sunday, from one month to the previous month, from one year to the previous year, and, finally, from one century to the previous century. (Yes, yes, purists. I know, I know. They were really a year out, but what the hell....) And, of course, by strolling back to the stern they could reverse it all once more.
Want to bet that some cruise organizer out there is already planning the
same thing for 1999 (and maybe 2000), with the added attraction of going from
one millenium to another? Interestingly, given the precision of modern GPS
navigation, only one ship is going to be able to claim that exact point of
intersection between the equator and the dateline. Wonder who'll win.
"Tel" - a word of Mesapotamian origin, referring to the mound created when successive generations of people inhabiting an area build newer structures on top of older ones.
I visited the archaeological site of Tel Abrak on Mar 21st, in the Emirate of Umm Al Quwain. There are a number of archaeological sites in the UAE, but this one is particularly exciting. Most sites in the world tell us about how a group of people lived during a certain period in history. However, a Tel shows us what happened during several ages, and also yields up clues surrounding the transition between them.
Tel Abrak was inhabited for about one thousand years, starting around 2500 BC. Presently the coastline is barely visible at the horizon, but in 2500 BC the water was only a few 100 metres away. The oldest structure is the foundation of a round tower, about 40 metres in diameter. This defensible structure was large enough for several people to live inside of it. The newer structures are additions in and around the tower. One new structure was the late addition of a kiln.
The walls are of two types: the tower and some interior walls were made from shaped stones sealed on top of one another, whereas other interior walls were made from clay.
A potentially exciting find was a tomb located in one corner of the tower. Unfortunately, all work on Tel Abrak ceased about 4 years ago, due to a border dispute between two Emirates - the current border runs right down the centre of the site, with the tomb being on the side whose government is opposed to further excavations. The tomb was covered with a tarpaulin, and refilled with dirt, to protect it for a future generation.
Tea & Oreos in the Astro Lounge at 3:30.
Bring your own dirt sifter.
I should also mention an interesting AAS session on "Careers Outside
Academe". Although not an education activity, per se, it did have many
implications for the way in which we educate astronomy majors and graduate
students. Several astronomy graduates now working outside astronomy
(including Martine Simard Normandin from our department) gave enlightening
presentations on career opportunities outside academe, and the skills and
attitudes required.
Doug Hube (PhD Toronto 1968) currently Professor, Department of Physics at
the University of Alberta and Joan Hube (BA Toronto 1961), currently in
the Office of the Faculty of Science, University of Alberta are members
of the local
organizing committee for the 1997 Annual General Meeting of CASCA to be
held in Edmonton, June 14-18. A registration package has been sent to all
members of CASCA. More details about the meeting, and about Edmonton and
Alberta, can be found on the CASCA'97 webpage:
Featured speakers at CASCA'97 include Vera Rubin and Alex Filippenko
We look forward to a large attendance and an opportunity to welcome past,
present and future friends and colleagues to Edmonton.
The ASP is a non-profit society, and our projects are designed to break
even. We still need your support through membership and donations. Often
we have "specials" - sign up (or sign up your friends), and receive a free
copy of an ASP Conference Series volume. I would be happy to tell you
more, or hear your comments about the ASP, or sign you up. E-mail can
be sent to me at the address
jpercy@erin.utoronto.ca
I thought I'd let you know what an ex-undergrad and Telescope Operator is up to.
I am now working on my Ph.D. with Larry Ramsey at Penn State University, building the first spectrograph for the largest telescope in the world: the Hobby Eberly Telescope. HET is a joint project of Penn State and the University of Texas, recently constructed on the McDonald Observatory site in West Texas. It's primary mirror contains 91 1-metre segments, and is 11 m in diameter!
The spectrograph I am building is a medium resolution (R~10000) fibre-fed bench-mounted echelle, and we expect to begin producing data with it in late May or early June. I will be in Texas this April, installing and testing the spectrograph which I built here in Pennsylvania.
I'm hoping to come back to Canada after my PhD - so if anyone
knows of any job opportunities starting around mid-1999, let me know!!
..Jason Harlow..
E-mail:harlow@astro.psu.edu
WWW: http://www.astro.psu.edu/users/harlow/
Dear Brian and Bob,
Your message with the invitation to contribute reaches me at Seattle, far from my home base, Bonn, Germany. Your deadline is today, so I cannot easily contribute much.
But I note that the work of Phil Kronberg and his group is reverberating through the particle physics community throughout the world because of the constraints that he was able to put on cosmological magnetic fields, which in turn has consequences for the propagation of very high energy charged particles, be it protons at ZeV energies, or monopoles. I keep meeting Phil at conferences organized by the particle physics community.
My stay at Toronto in the late 70s keeps inspiring me to continue to consider starburst galaxies such as M82; right now I have a Chinese student and she is doing some very interesting calculations for starbursts in young galaxies.
All the best ... from Seattle.
Peter L. Biermann
March 20, 1997
Much has changed with me since the last time we talked. I am finishing up a project on recombination in the early universe. (z = 10000 to z = 100). Basically I coded a model of helium and hydrogen recombination ( and other chemistry), with 100 level atoms and many, many other details. This was a major refinement of work done in the 1960s by Peebles, who, understandably for that time, used a lot of approximations. It is an interesting field because the density of electrons with time plays a large role in the determination of the CMB temperature fluctuations on the sky today, which is what COBE measured. And you know the cosmologists believe that with the next generation of COBE satellites the parameters (H, Omega ...) of the universe will all be determined! Next week I will be doing an oral exam on this. Here the masters degree is only 1 year of courses, but before proceeding to the PhD one is expected to present an original research project and defend it.
For my thesis I am planning (with Dimitar [Sasselov]) to model the 51 Peg type planetary atmospheres. This turns out to be closer to a stellar atmospheres problem, of interacting binaries, but with a very cool planet instead of a star.
Alas, I do no observing whatsoever, but I happily write large computer programs. You were right in that the time at DDO gave me a good education about the basics of observing!
I have discovered a new sport: telemarking. It is
a hybrid between downhill and x-c skiing. 2hrs north
of Boston there are the White Mountains. They are always
crowded but skiing is extremly exhilarating. And although
there is hardly any snow here, the mountains are high
enough to have lots of it. Telemarking allows
you to skip the lift areas, and instead ski up a mountain
( a couple at 1000 ft) and then down again, turning
through thinly forested hillsides, or on a narrow trail.
Don't worry - I am still a beginner
so am slow and cautious. But I did see someone ski down
a frozen waterfall, turning in knee deep powder!
Regards,
Sara
Apr 2 G2000
Apr 9 Simon Morris, DAO
Low Redshift Ly-alpha Absorption Systems
Apr 16 G2000
Apr 23 Patrick Thaddeus, CfA, (Joint Astronomy-CITA colloquium)
Large Organic Molecules in the Interstellar Gas
Clement, C.M.; Shelton, I. The structure of the light curves of the RR Lyrae variables in the Oosterhoff type I cluster NGC 6171. 18-Feb-1997. Preprint No. 97-0225
Maceroni, C.; Rucinski, S.M. The shortest-period M-dwarf eclipsing system BW3 V38. 6-Mar-1997. Preprint No. 97-0285
Rucinski, S.M. EUVE investigation of three short-period binary stars. 13-Mar-1997. Preprint No. 97-0303
Schade, D.; Barrientos, L.F.; Lopez-Cruz, O. Evolution of
cluster ellipticals at 0.2 < z < 1.2 from Hubble Space Telescope
imaging. 28-Jan-1997. Preprint No. 97-0145
That supreme revisionist of them all, Nicholas Copernicus, at the end of his
life wrote a grand mathematical synthesis of his sun-centred theory of the
planetary system. This was his book, De Revolutionibus Orbium Coelesticum. At
the time it went over like a lead balloon, but Owen Gingerich, who has made a
crusade out of tracking down first editions of De Rev, reported recently that a
first edition is now worth US$300,000. Not bad, eh, considering that Copernicus
would never have made tenure at a modern university on his lifetime record of
one book, one preprint, one Letter, and no teaching experience.
Don Fernie