Distant EKOs, Issue #89  (October 2013)


News & Announcements
Abstracts of 3 Accepted Papers
Title of 1 Submitted Paper
Title of 1 Other Conference Contribution
Conference Information
Newsletter Information


There were 2 new Centaur/SDO discoveries announced since the previous issue of Distant EKOs:

2013 RN30, 2013 TP145

Reclassified objects:

2011 GM27 (SDO $\rightarrow$ TNO)

Current number of TNOs: 1259 (including Pluto)
Current number of Centaurs/SDOs: 377
Current number of Neptune Trojans: 9

Out of a total of 1645 objects:
   642 have measurements from only one opposition
     631 of those have had no measurements for more than a year
       324 of those have arcs shorter than 10 days
(for more details, see: http://www.boulder.swri.edu/ekonews/objects/recov_stats.jpg)


Discovery of a New Member of the Inner Oort Cloud from The Next Generation Virgo Cluster Survey
Ying-Tung Chen1, J.J. Kavelaars2, Stephen Gwyn2, Laura Ferrarese2, Patrick Côté2, Andrés Jordán3, Vincent Suc3, Jean-Charles Cuillandre4, and Wing-Huen Ip1

1 Institute of Astronomy, National Central University, No. 300, Jhongda Rd, Jhongli City, Taoyuan County 32001, Taiwan
2 Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC V9E 2E7, Canada
3 Departamento de Astronomíca y Astrofísica, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Macul 7820436, Santiago, Chile
4 Canada-France-Hawaii Telescope Corporation, 65-1238 Mamalahoa Hwy., Kamuela, HI 96743, USA

We report the discovery of 2010 GB174, a likely new member of the Inner Oort Cloud (IOC). 2010 GB174 is one of 91 Trans Neptunian Objects (TNOs) and Centaurs discovered in a 76 deg2 contiguous region imaged as part of the Next Generation Virgo Cluster Survey (NGVS) -- a moderate ecliptic latitude survey reaching a mean limiting magnitude of $g^\prime \simeq 25.5$ -- using MegaPrime on the 3.6m Canada France Hawaii Telescope. 2010 GB174 is found to have an orbit with semi-major axis $a\simeq350.8$ AU, inclination $i
\simeq 21.6^\circ$ and pericentre $q\sim48.5$ AU. This is the second largest perihelion distance among known solar system objects. Based on the sky coverage and depth of the NGVS, we estimate the number of IOC members with sizes larger than 300 km ($H_V \le 6.2$ mag) to be $\simeq 11\,000$. A comparison of the detection rate from the NGVS and the PDSSS (a characterized survey that `re-discovered' the IOC object Sedna) gives, for an assumed a power-law LF for IOC objects, a slope of $\alpha \simeq 0.7 \pm 0.2$, with only two detections in this region this slope estimate is highly uncertain.

Published in: The Astrophysical Journal Letters, 775, L8 (2013 September 20)

For preprints, contact charles@astro.ncu.edu.tw
or on the web at http://iopscience.iop.org/2041-8205/775/1/L8/
and http://arxiv.org/abs/1308.6041

A Study of the High-inclination Population in the Kuiper Belt -
1. The Plutinos
J. Li1, L.-Y. Zhou1, and Y.-S. Sun1

1 School of Astronomy and Space Science & Key Laboratory of Modern Astronomy and Astrophysics in Ministry of Education, Nanjing University, Nanjing 210093, PR China

The dynamics of the high-inclination Plutinos is systematically studied. We first present the peculiar features of the 2:3 Neptune mean motion resonance (NMMR) for inclined orbits, especially for the correlation of resonant amplitude $A_{\sigma}$ with inclination i. Using the numerical integrations for the age of the Solar system, the dynamical structure of the 2:3 NMMR is mapped out on the plane of semi-major axis versus i for different eccentricities. We have shown that i of stable resonant orbits could be as high as $90^{\circ}$; and the stable region is roughly surrounded by the contours of $A_{\sigma}=120^{\circ}$. These new findings allow us to further explore the 2:3 NMMR capture and retention of planetesimals with initial inclinations $i_0 \le 90^{\circ}$ in the frame of the planet migration model. We find that the outward transportation of Plutinos is possible for any inclined or even perpendicular orbits.

The role of i0 in the formation of Plutinos during Neptune's migration is highlighted and interesting results are obtained: (1) The capture efficiency of the 2:3 NMMR decreases drastically first with the increase of i0, but it then raises instead when i0 exceeds $\sim50^{\circ}$; (2) The magnitude of i-variation is limited to less than $5^{\circ}$ for any i0, and moreover, for Plutinos with $i\ge48^{\circ}$, their i are forced to decrease throughout the outward migration; (3) Plutinos with $i\ge48^{\circ}$ are certainly outside the Kozai mechanism, since an inclination increase is prohibited by the migrating 2:3 NMMR; (4) The 7:11 inclination-type NMMR could be responsible for nearly-circular Plutinos, and a minimum $i_0\sim15^{\circ}$ is required to intrigue this mechanism.

To appear in: Monthly Notices of the Royal Astronomical Society

Preprints available on the web at http://arxiv.org/abs/1310.0907 and

The Small Numbers of Large Kuiper Belt Objects
Megan E. Schwamb1,2,3,4, Michael E. Brown4, and Wesley C. Fraser4,5

1 Institute of Astronomy and Astrophysics, Academia Sinica, 11F of Astronomy-Mathematics Building, National Taiwan University. No.1, Sec. 4, Roosevelt Rd, Taipei 10617, Taiwan
2 Yale Center for Astronomy and Astrophysics, Yale University,P.O. Box 208121, New Haven, CT 06520
3 Department of Physics, Yale University, New Haven, CT 06511, USA
4 Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
5 Herzberg Institute of Astrophysics, National Research Council, 5071 W. Saanich Road,Victoria, BC, V9E 2E7, Canada

We explore the brightness distribution of the largest and brightest (m(R)<22) Kuiper belt objects (KBOs). We construct a luminosity function of the dynamically excited or hot Kuiper belt (orbits with inclinations > 5$^{\circ}$) from the very brightest to m(R)=23. We find for m(R) ${\hbox{\rlap{\hbox{\lower4pt\hbox{$\sim$}}}\hbox{$<$}}}$ 23, a single slope appears to describe the luminosity function. We estimate $\sim$12 KBOs brighter than m(R)$\sim$19.5 are present in the Kuiper belt today. With 9 bodies already discovered this suggests that the inventory of bright KBOs is nearly complete.

To appear in: The Astronomical Journal

Preprints available at http://arxiv.org/abs/1310.7049


The Size-distribution of Scattered Disk TNOs from that of JFCs between 0.2 and 15 km Effective Radius

Michael J.S. Belton1

1 Belton Space Exploration Initiatives, Tucson, AZ, USA

Submitted to: Icarus

For preprints, contact mbelton@dakotacom.net


Positions of Pluto Extracted from Digitized Pulkovo Photographic Plates Taken in 1930 - 1960
E.V. Khrutskaya1, J.-P. De Cuyper2, S.I. Kalinin1, A.A. Berezhnoy1, and G. de Decker2

1 Pulkovo Observatory, 65/1 Pulkovskoye chaussee, Saint Petersburg, 196140, Russia
2 Royal Observatory of Belgium, Ringlaan 3, B-1180 Ukkel, Belgium

We present the results of determination of Pluto's positions derived from photographic plates taken in 1930-1960. Observations were made with Normal Astrograph at Pulkovo Observatory. Digitization of these plates was performed with high precision scanner at Royal Observatory of Belgium (ROB Digitizer). Mean values of standard errors of plate positions (x,y) lie between 12 and 18 mas. The UCAC4 catalogue was used as an astrometric calibrator. Standard errors of equatorial coordinates obtained are within 85 to 100 mas. Final table contains 63 positions of Pluto referred to the HCRF/UCAC4 frame. This work was performed with support from the Russian Foundation for Basic Research (project no. 12-02-00675a).

Published in: Proc. of All-Russian Astronomical Conference, Saint Petersburg,

2013 September 23-27, 2013, 265

For preprints, contact deimos@gao.spb.ru
or on the web at http://arxiv.org/abs/1310.7502


48th ESLAB Symposium: New insights into volcanism across the Solar System
First announcement


Dear colleagues,

We are pleased to invite you to the 48th ESLAB Symposium on "New insights into volcanism across the Solar System". The Symposium will take place from 16-20 June 2014 at the European Space Research and Technology Centre (ESTEC) located in Noordwijk, The Netherlands.

It will focus on volcanism in the Solar System. Of particular interest, but not limited to, will be new insights obtained over the last years from international space missions to planets (e.g., MESSENGER, LRO, Selene, etc.), Moons and cryo-volcanism. The connection with Earth by will be covered by experts on terrestrial volcanism.

The format will be made up of plenary sessions on topics related to volcanism in the Solar System, with contributed oral and poster presentations. Part of the Symposium may be devoted to parallel sessions on specialized topics where details can be discussed at greater length. This will depend on the response to the Call for Papers.

The second announcement with the call for abstracts and other detailed information is available on the meeting website: | http://congrexprojects.com/2014-events/48-ESLAB/ |

Pre-registration is already available on this website which will ensure that you receive regular updates from the Symposium organisers.

Financial support may be available for students.

Kind regards,

The LOC, 48th ESLAB

Newsletter Information

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.

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Moving ... ??

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Joel Parker 2013-12-12