Contents

Editorials & Short Articles
News & Announcements
Abstracts of 5 Accepted Papers
Titles of 2 Submitted/Other Papers
Titles of 30 Conference Contributions
Newsletter Information

EDITORIALS & SHORT ARTICLES

The first issue of the Distant EKOs newsletter was well received, and with this second issue there are some new additions:

• A Distant EKOs webpage is now available at: http://www.boulder.swri.edu/ekonews

  The web pages contain current and past issues of the newsletter in various formats (PostScript, PDF, HTML) so those of you who prefer not extracting and compiling the L^ATEX version can get the issues there.

  Also on these pages are:
  Extensive lists of articles and references with links to the abstracts and full articles;
  Tables of all EKOs and Centaurs, giving coordinates and published observations (photometry by filter, spectroscopy, etc.) for each object, with links to each article that presents the data;
  A glossary targeted to the casual web-reader, journalist, etc. who may not know some of the specialized terms you may use in your papers. (If you have or know of similar glossary/jargon definition pages that I could include as links, or if you would like to add some definitions I missed, let me know.)
  Links to other related sites of interest to Kuiper belt researchers.

• Also in response to those who weren't able or interested in dealing with the L^ATEX version of the newsletter, at the beginning of each issue that is e-mailed out, there is a plain-text list of the contents (just titles, and references with contact/link information) at the beginning of the e-mail message. So now you can just browse that information to find out what new items are available, then go to the Distant EKOs webpage for more details.

And thanks again to everyone who has given me feedback on the Newsletter and the web pages. Any comments/suggestions are always welcome.

NEWS & ANNOUNCEMENTS

A new Centaur, 1998 SG₃₅, has been discovered, bringing the total number of known Centaurs to eight. See MPEC 1998-S41 (http://cfa-www.harvard.edu/cfa/ps/mpec/J98/J98S41.html). Observers are encouraged to obtain recovery observations to avoid losing this object.

PAPERS ACCEPTED TO JOURNALS

Pencil-Beam Surveys for Faint Trans-Neptunian Objects

B. Gladman¹, J. Kavelaars², P. Nicholson³, T. Loredo³and J.A. Burns³

¹ Observatoire de Nice, B.P. 4229, 06304 Nice Cedex 4, FRANCE
² Dept. of Physics and Astronomy, McMaster University, CANADA
³ Department of Astronomy, Cornell University, USA

Motivated by a desire to understand the size distribution of objects in the Edgeworth-Kuiper belt, an observing program has been conducted at the Palomar 5-m and Canada-France-Hawaii 3.6-m telescopes. We have conducted pencil-beam searches for outer solar system objects to a limiting magnitude of . The fields were searched using software recombinations of many short exposures shifted at different angular rates in order to detect objects at differing heliocentric distances. Five new trans-neptunian objects were detected in these searches. Our combined data set provides an estimate of trans-neptunian objects per square degree brighter than . This estimate is a factor of 3 above the expected number of objects based on an extrapolation of previous surveys with brighter limits, and appears consistent with the hypothesis of a single power-law luminosity function for the entire trans-neptunian region. Maximum likelihood fits to all self-consistent published surveys with published efficiency functions predicts a cumulative sky density $\Sigma(<R)$ obeying $\log \Sigma = 0.76(R-23.4)$ objects per square degree brighter than a given magnitude R.

To appear in: Astronomical Journal, 116, 2042-2054

For preprints contact gladman@obs-nice.fr

Observations of Distant Solar System Bodies

P. Magnusson¹, C.-I. Lagerkvist¹, J.S.V. Lagerros¹M. Dahlgren¹M. Lundström¹

¹ Astronomiska Observatoriet, Box 515, S-752 20 Uppsala, Sverige

Multicolour VRI photometry and astrometry of one Centaur and seven Edgeworth-Kuiper objects were obtained. One object, 1994 JQ₁, may be as red as 5145 Pholus, the reddest minor planet previously known. The Centaur 1995 DW₂ has more moderate colour indices, similar to main-belt asteroids. Seven R-magnitudes were obtained for 1994 JS, 1995 FB₂₁, and 1995 GY₇. No light variation above the expected noise is evident, apart from a few outliers. A total of 47 astrometric positions were obtained for the eight objects. The four nights of observations with the ESO New Technology Telescope covered 0.52 square degrees. Two previously unknown objects, 1995 FB₂₁ and 1995 GY₇, were discovered. We estimate the density of Edgeworth-Kuiper objects brighter than R=24 to be 5.3 per square degree of sky near the ecliptic.

To appear in: Astronomische Nachrichten, 319, 251

A Dust Ring around Eridani: Analog to the Young Solar System

J.S. Greaves¹, W.S. Holland¹, G. Moriarty-Schieven¹,
T. Jenness¹, W.R.F. Dent², B. Zuckerman³, C. McCarthy³,
R.A. Webb³, H.M. Butner⁴, W.K. Gear⁵ and H.J. Walker⁶

¹ Joint Astronomy Centre, 660 N. A`ohoku Place, University Park, Hilo, HI 96720
² Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, U.K.
³ Department of Astronomy, University of California, Los Angeles, Los Angeles, CA 90095
⁴ SMTO, University of Arizona, Tucson, AZ 85721
⁵ Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT, U.K.
⁶ CLRC, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, U.K.

Dust emission around the nearby star Eridani has been imaged using a new submillimetre camera (SCUBA at the JCMT). At 850 wavelength a ring of dust is seen, peaking at 60 AU from the star and with much lower emission inside 30 AU. The mass of the ring is at least 0.01 M in dust, while an upper limit of 0.4 M in molecular gas is imposed by CO observations. The total mass is comparable to the estimated amount of material, 0.04-0.3 M , in comets orbiting the Solar System.

The most probable origin of the the ring structure is that it is a young analogue to the Kuiper Belt in our Solar System, and that the central region has been partially cleared by the formation of grains into planetesimals. Dust clearing around Eri is seen within the radius of Neptune's orbit, and the peak emission at 35-75 AU lies within the estimated Kuiper Belt zone of 30-100 AU radius. Eri is a main-sequence star of type K2V (0.8 M) with an estimated age of 0.5-1.0 Gyr, so this interpretation is consistent with the early history of the Solar System where heavy bombardment occurred up to  0.6 Gyr. An unexpected discovery is substructure within the ring, and these asymmetries could be due to perturbations by planets.

To appear in: Astrophysical Journal Letters, 506, L133

For preprints, contact jsg@jach.hawaii.edu
or on the web at http://www.journals.uchicago.edu/ApJ/journal/contents/ApJL/v506n2.html

Search for Trans-Neptunian Objects: An Automated Technique Applied to Images Obtained with the UH 8k CCD Mosaic Camera

P. Rousselot¹, F. Lombard¹, and G. Moreels¹

¹ Observatoire de Besançon, BP 1615, 25010 Besançon Cedex, France

In this paper we present the results obtained with a new program dedicated to the automatic detection of trans-Neptunian objects (TNOs) with standard sets of images obtained in a same field of view. This program is available freely from the World Wide Web server of the Observatory of Besançon (http://www.obs-besancon.fr/www/publi/philippe/tno.html) and is designed to be used with the Munich Image Data Analysis System (MIDAS) developed by The European Southern Observatory (ESO). It has been tested with observational data collected with the UH 8k CCD mosaic Camera on October 27, 1997, at the prime focus of the CFH telescope (Mauna Kea, Hawaii). These observational data had lead, by the classical method of blinking, to a first detection of a new TNO with a magnitude estimated at 23.6 and an unusually high orbital inclination (i33). The program managed to detect this object, as well as detecting another TNO (23.9), confirming its ability to detect faint moving objects. To appear in: Astronomy & Astrophysics

For preprints contact philippe@obs-besancon.fr

Detection of Water Ice on Nereid

M.E. Brown¹, C.D. Koresko¹, and G.A. Blake¹

¹ Division of Geological and Planetary Science, Caltech

We report the detection of the 1.5 and 2.0 m absorption bands of water ice in the near-infrared reflection spectrum of Neptune's distant irregular satellite Nereid. The spectrum and albedo of Nereid appear intermediate between those of the Uranian satellites Umbriel and Oberon, suggesting a surface composed of a combination of water ice frost and a dark and spectrally neutral material. In contrast, the surface of Nereid appears dissimilar to those of the outer solar system minor planets Chiron, Pholus, and 1997 CU₂₆. The spectrum thus provides support to the hypothesis that Nereid is a regular satellite formed in a circum-planetary environment rather than a captured object.

To appear in: Astrophysical Journal Letters, Dec 1, 1998.

Preprints on the web at http://www.gps.caltech.edu/~mbrown/papers/pubs.html

SUBMITTED PAPERS AND OTHER ARTICLES

Kuiper Belt Evolution due to Dynamical Friction
A. Del Popolo^1,2, E. Spedicato², M. Gambera^1,3
1 Istituto di Astronomia dell'Università Catania, Viale A.Doria, 6 - I 95125, Catania, Italy
³ Dipartimento di Matematica, Università Statale di Bergamo, Piazza Rosate, 2 - I 24129, Bergamo, Italy
³ Observatoria Astrofisico di Catania and CNR-GNA, Viale A.Doria, 6 - I 95125, Catania, Italy
Submitted to: Astronomy & Astrophysics

For reprints contact: antonino@astrct.ct.astro.it

Origin of Trans-Neptunian Asteroids
A. T. Van Flandern^1
1 Meta Research, P.O. Box 15186, Chevy Chase, MD 20825
Published in: Meta Research Bulletin, vol. 4, #3, pp. 42-46

Available on the web at http://www.metaresearch.org/mrb/trans-NeptunianAsteroids.htm

CONFERENCE CONTRIBUTIONS

I've done a search of the abstracts from the recent DPS meeting to find all(?) papers related to the Kuiper belt. The abstracts are available via the web links given, but also through the AAS web page: http://www.aas.org/publications/baas/v30n3/dps98/SL.htm

The discovery of two irregular Uranian satellites
Nicholson, P. D.¹, Burns, J. A.¹, Gladman, B. J.², Kavelaars, J. J.³, Marsden, B. G.⁴, Williams, G. V.⁴, Aksnes, K.⁴, & Offutt, W. B.^5
1Cornell, ²CITA, ³McMaster University, ⁴SAO, ⁵Cloudcroft NM

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DDA....30.1201N

High-eccentricity non-secular Three-Period Resonances inside Two-period Resonances (Kirkwood Gaps)
Ferraz-Mello, S.¹, Michtchenko, T.A.¹, & Roig, F.^1
1IAGUSP, Univ. Sao Paulo, Brazil

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.1001F

Elementary/Middle School Activities on Scale and Distance in the Solar System
Urquhart, M. L.^1
1U of Colorado

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.1805U

Middle School Adventures in Planetary Exploration
Limaye, S. S.¹ & Pertzborn, R. A.^1
1Space Science & Engineering Center, UW-Madison

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.1811L

Giant planet orbital migration in the early Solar system
Malhotra, R.^1
1LPI

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.2109M

Radial Migration of Planets Embedded in a Massive Planetesimal Disk
Hahn, J.M.¹ & Malhotra, R.^1
1LPI

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.2110H

Imaging a Circumstellar Disk around a Star with a Radial-Velocity Planetary Companion
Trilling, D. E.¹ & Brown, R. H.^1
1LPL

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.2303T

Signatures of Planets on Extra-solar Circumstellar Dust Disk
Liou, J.-C.¹ & Zook, H. A.^2
1GB Tech/Lockheed Martin, ²NASA/JSC

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.2304L

Observation of solar-system objects with the ISO satellite
Encrenaz, T.^1
1DESPA, Paris-Meudon Observatory, France

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.2601E

ISOPHOT observations of the Pluto-Charon system: Pluto's thermal lightcurve
Lellouch, E.¹, Laureijs, R.², Schmitt, B.³, Quirico, E.⁴, De Bergh, C.⁵, Crovisier, J.⁵, & Coustenis, A.^5
1Obs. Meudon, ²ISO SOC, Villafranca, ³LGGE, Grenoble, ⁴IAS, Orsay, ⁵Obs. Meudon

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.2707L

ISO Spectroscopic Observations of comets 22P/Kopff and
103P/Hartley 2
Crovisier, J.¹, Bockelee-Morvan, D.¹, Encrenaz, T.¹, Lellouch, E.¹, Altieri, B.², Leech, K.², Salama, A.², Griffin, M.³, De Graauw, T.⁴, Van Dishoeck, E.⁵, Knacke, R.⁶, & Brooke, T.Y.^7
1Obs. Paris, ²ESA, Villafranca, ³Queen Mary and Westfield College, London, ⁴SRON, Groningen, ⁵Leiden Obs., ⁶Penn. State Erie, ⁷J.P.L.

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.2708C

Centaur 5145 Pholus As a Comet Nucleus
Cruikshank, D. P.¹, Roush, T. L.¹, Bartholomew, M. J.¹, Pendleton, Y. J.¹, White, S. M.¹, Bernstein, M. P.¹, Dalle Ore, C. M.¹, Khare, B. N.¹, Geballe, T. R.², Davies, J. K.², Owen, T. C.³, Tholen, D. J.³, De Bergh, C.⁴, Bell, J. F., III⁵, Brown, R. H.⁶, & Tryka, K. A.^7
1NASA Ames, ²JAC Hawaii, ³IFA Hawaii, ⁴Obs. Paris, ⁵Cornell U., ⁶LPL Arizona, ⁷NAU/JPL

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.4201C

Pluto's Atmosphere above 1500 km
Krasnopolsky, V. A.¹ & Cruikshank, D. P.^2
1CUA/NASA GSFC, ²NASA Ames

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.4906K

Seasonal Monitoring of Pluto: 1998 Status Report
Buie, M. W.¹ & Grundy, W. M.^1
1Lowell Observatory

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.4907B

Reflectance Spectroscopy of the Individual Members of the
Pluto/Charon System: HST/NICMOS Results
Dumas, C.¹, Terrile, R. J.¹, Burgasser, A.², Brown, R.³, Rieke, M.³, Schneider, G.³, Thompson, R.³, & Koerner, D.^4
1JPL, ²Caltech, ³Univ. Arizona, ⁴Univ. Pennsylvania

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.4908D

The Diameter of Pluto: A Re-Analysis of Kuiper's Disk Meter Measurements
Marcialis, R.L.¹ & Merline, W. J.^2
1LPL/U. Arizona, ²SWRI

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.4910M

Two Distinct Populations of Kuiper Belt Objects
Tegler, S.C.¹ & Romanishin, W.^2
1Northern Arizona Univ, ²Univ Oklahoma

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.5101T

Spectroscopic observations of Edgeworth-Kuiper Belt (EKB) objects
Barucci, M.A.¹, Tholen, D. J.², Doressoundiram, A.³, Fulchignoni, M.⁴, & Lazzarin, M.^5
1Paris Obs., ²Univ. Hawaii, ³Torino Obs., ⁴Univ. Paris VII, ⁵Padova Obs.

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.5102B

Physical Studies of Kuiper Belt Objects with NICMOS
Noll, K. S.¹ & Luu, J.^2
1STScI, ²Leiden Univ.

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.5103N

Infrared Spectroscopy of Centaurs and Irregular Satellites
Brown, M. E.^1
1Caltech

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.5104B

Evolution of an Initial Massive Edgeworth-Kuiper Belt: Accretion and Collisional History
Davis, D. R.¹ & Farinella, P.^2
1Planetary Science Institute, ²Universit'a di Pisa

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.5105D

Collisional and Cratering Rates in the Kuiper Belt: Applications to Surface Activation and Modification
Durda, D. D.¹ & Stern, S. A.^1
1Southwest Research Institute

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.5106D

Simulations of the Formation of the Oort Cloud of Comets
Dones, L.¹, Duncan, M. J.², Levison, H. F.³, & Weissman, P. R.^4
1NASA Ames and SJSU Foundation, ²Queen's University, ³Southwest Research Institute, Boulder, ⁴Jet Propulsion Laboratory

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.5107D

Stellar Perturbations of the Kuiper Belt
Weissman, P. R.^1
1Jet Propulsion Laboratory

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.5108W

The Spacewatch Survey for Bright Kuiper Belt Objects
Larsen, J. A.^1
1Lunar and Planetary Laboratory, University of Arizona

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.5109L

Search for Trans-Neptunian Objects: a new MIDAS context confronted with some results obtained with the UH 8k CCD Mosaic Camera
Rousselot, P.¹, Lombard, F.¹, & Moreels, G.^1
1Observatoire de Besanceon

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.5110R

Progress Report on the 1.8-meter Spacewatch Telescope
McMillan, R. S.¹, Bressi, T. H.¹, Descour, A. S.¹, Gehrels, T.¹, Larsen, J. A.¹, Montani, J. L.¹, Perry, M. L.¹, Read, M. T.¹, & Tubbiolo, A. F.^1
1LPL/U.Az.

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.5111M

Spectroscopic investigation of the Centaurs
Lazzarin, M.¹ & Barucci, M.A.^2
1Astronomy Dpt., Padova University, ²Observatoire de Paris

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.5112L

1-2 Micron Grism Spectroscopy of Centaurs and Kuiper Belt Objects from NICMOS
McCarthy, D.W.¹, Campins, H.¹, Kern, S.¹, Brown, R. H.¹, Stolovy, S.¹, & Rieke, M.^1
1UAZ

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.5113M

The Dusty Carbon Monoxide Coma of (2060) P/Chiron
Sekiguchi, T.¹, Watanabe, J.¹, & Boice, D. C.^1
1National Astronomical Observatory of Japan

Abstract available at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998DPS....30.5114S

The Distant EKOs Newsletter is dedicated to provide researchers with easy and rapid access to current work regarding the Kuiper belt (observational and theoretical studies), directly related objects (e.g., Pluto, Centaurs), and other areas of study when explicitly applied to the Kuiper belt.

We accept submissions for the following sections:

• Abstracts of accepted papers
• Titles of submitted (but not yet accepted) papers and conference articles
• Thesis abstracts
• Short articles, announcements, or editorials
• Status reports of on-going programs
• Requests for collaboration or observing coordination
• Table of contents/outlines of books
• Announcements for conferences
• Job advertisements
• General news items deemed of interest to the Kuiper belt community

A LaTeX template for submissions is appended to each issue of the newsletter, and is sent out regularly to the e-mail distribution list. Please use that template, and send your submission to: ekonews@boulder.swri.edu The Distant EKOs Newsletter is available on the World Wide Web at: http://www.boulder.swri.edu/ekonews Recent and back issues of the Newsletter are archived there in various formats. The web pages also contain other related information and links.

Distant EKOs is not a refereed publication, but is a tool for furthering communication among people interested in Kuiper belt research. Publication or listing of an article in the Newsletter or the web page does not constitute an endorsement of the article's results or imply validity of its contents. When referencing an article, please reference the original source; Distant EKOs is not a substitute for peer-reviewed journals.

Moving ... ??

If you move or your e-mail address changes, please send the editor your new address. If the Newsletter bounces back from an address for three consecutive issues, the address is deleted from the mailing list. All address changes, submissions, and other correspondence should be sent to: ekonews@boulder.swri.edu