Categoría: Papers and Letters

 

In the main belt of asteroids, there exist pairs of asteroids that are on highly similar heliocentric orbits. They were discovered by Vokrouhlický and Nesvorný (2008) who showed that the asteroid pairs cannot be random coincidences of unrelated asteroids from the local asteroid population, but most of them must be genetically related pairs.

Being motivated by the progress in our knowledge and understanding of asteroid pairs, we underwent a thorough photometric study of a sample of nearly 100 asteroid pairs.

http://aptog.com/wp-content/uploads/2019/07/astpairscomplex_Icarus_333_pp429_463.pdf

We report on the discovery that minor planet 5674 Wolff
is a fully-synchronous binary system with an orbital
period of 93.7 ± 0.2 h. The combined primary+secondary
rotation amplitude is 0.52 ± 0.02 mag. A lower limit on
the secondary-to-primary mean diameter ratio is D2/D1 =
0.80.

http://aptog.com/wp-content/uploads/2019/07/2016MPBu___43__250A.pdf

https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/sty3250/5228750?guestAccessKey=2ed14d75-36d3-4ea8-856f-8b3d0d813ca9

The study of minor planets is motivated both by fundamental science of Solar System origins (some of these bodies contain the most pristine materials from the early ages of the planetary nebula), and by practical reasons concerning space exploration and impact frequency with Earth. Among minor bodies, near-Earth asteroids (NEAs) are a particularly important group: these objects are nearby the Earth’s orbit and they represent both resources and hazards to humans. This is the case of 2014 JO₂₅.

We report that asteroid 2207 Antenor is a very likely
binary asteroid candidate. If confirmed, it would be the
fifth known binary Jovian Trojan asteroid.

45-419 Stephens etal – 2207

The near-Earth asteroid (NEA) 1993 RA was observed
with the 2.5-m Isaac Newton Telescope (INT) in full
Moon conditions for 8h total during three successive
nights (2017 Oct 3-6). The composite lightcurve could
be fit by a 3-order period P = 5.64 ± 0.01 h with
amplitude of 0.13 mag; other solutions are possible.

2018MPBu___45___96V

CCD photometric observations of the near-Earth
asteroid (190166) 2005 UP156 in 2017 May show it to
be a fully-synchronous binary with rotation and orbital
period P = 40.542 ± 0.008 h. The estimated effective
diameter ratio of the two bodies is 0.8 ± 0.1. However,
the 0.5 mag out-of-eclipse lightcurve indicates quite
elongated shapes and so the size ratio should be viewed
with caution.

2017MPBu___44__324W

Lightcurves of six Mars-crossing and eight main-belt
asteroids were obtained at APT-Observatory Group
from 2017 April to September. In addition, two more
asteroids were captured in 2014 and 2015 during the
EURONEAR project. Analysis of rotation period,
lightcurve amplitude, and physical parameters (size and
axis size relationship) are presented.

2018MPBu___45___92A

We report that asteroid (24495) 2001 AV1 is a binary
asteroid. It is another candidate for the special case of
very wide binaries. The primary lightcurve has a period
of 24.083 ± 0.005 h and an amplitude 0.58 ± 0.05 mag.
and the secondary lightcurve has a period of 2.7375 ±
0.0001 h.

2017MPBu___44__319S

IAU CBET 4570

(20882) 2000 VH57
B. D. Warner, Center for Solar System Studies (CS3), Landers, CA, USA.,
A. Aznar Macias, APT Observatories Group, M. Serra-Ricart and J.
Licandro, Instituto de Astrofísica de Canarias-IAC, and P. Pravec,
Ondrejov Observatory report that photometric observations obtained with a
0.25-m telescope at the CS3 facility in Landers, CA, USA, and 0.45-m telescope
at the Canary Astrophysics Institute, from 2018 September 15 through October 20
reveal that the inner main-belt minor planet (20882) 2000 VH57 is a binary system
with an orbital period of 32.81 +/- 0.02 hr. The primary shows a period of
2.5586 +/- 0.0001 hr and has a maximum lightcurve amplitude of 0.15 mag at solar
phase angles from 19 degrees in mid-September down to 2 degrees in mid-October.
The nearly-symmetrical shape and amplitude of the lightcurve suggest that the
primary shape is near spheroidal.

2018 November 08,  Daniel W. E. Green

http://www.cbat.eps.harvard.edu/cbet/RecentCBETs.html

IAU CBET 4565

(100015) 1989 SR7
V. Benishek, Belgrade Astronomical Observatory; P. Pravec, H. Kucakova,
K. Hornoch, and P. Kusnirak, Ondrejov Observatory; J. Oey, Blue Mountains
Observatory, Leura, NSW, Australia; R. Groom, Darling Range Observatory,
Perth, Western Australia; A. Aznar, Astronomia Para Todos Observatories Group,
Spain; and A. Sota, Observatorio de Sierra Nevada, Instituto de Astrofisica de
Andalucia-CSIC, report that photometric observations taken with a 0.35-m
telescope at the Sopot Observatory in Serbia, a 0.65-m telescope at the
Ondrejov Observatory, a 0.35-m telescope at the Blue Mountains Observatory, a
0.30-m telescope at the Darling Range Observatory, and a 0.90-m telescope at
the Sierra Nevada Observatory during Sept. 9-Oct. 12 reveal that minor planet
(100015) is a binary system with an orbital period of 20.65 ± 0.01 hr. The
primary shows a period of 2.4172 ± 0.0002 hr and has a lightcurve amplitude
of 0.05 mag at solar phases 7-22 degrees, suggesting a nearly spheroidal
shape. Mutual eclipse/occultation events that are 0.13 to 0.21 magnitude deep
indicate a secondary-to-primary mean-diameter ratio of 0.35 ± 0.02. The
mean absolute R magnitude in the Cousins system is H_R = 15.55 ± 0.11,
assuming the phase-relation slope parameter G = 0.24 ± 0.11.

2018 October 23,  Daniel W. E. Green

http://www.cbat.eps.harvard.edu/cbet/RecentCBETs.html

IAU CBET 4563

(2178) KAZAKHSTANIA
V. Benishek, Belgrade Astronomical Observatory; P. Pravec, H. Kucakova,
and K. Hornoch, Ondrejov Observatory; V. Chiorny, Kharkiv Observatory; F.
Pilcher, Organ Mesa Observatory, Las Cruces, NM, U.S.A.; A. Aznar, Astronomia
Para Todos Observatories Group, Spain; and V. Casanova, Observatorio de Sierra
Nevada, Instituto de Astrofisica de Andalucia, Consejo Superior de
Investigaciones Cientificas, report that photometric observations taken with a
0.35-m telescope at the Sopot Observatory in Serbia, a 0.65-m telescope at the
Ondrejov Observatory, a 0.70-m telescope at the Chuguev station of the Kharkiv
Observatory in Ukraine, a 0.35-m telescope at the Organ Mesa Observatory, and
a 0.90-m telescope at Sierra Nevada Observatory during Sept. 18-Oct. 15 reveal
that minor planet (2178) is a binary system with an orbital period of 18.504
± 0.006 hr. The primary shows a period of 3.0183 ± 0.0002 hr and has a
light-curve amplitude of 0.31 mag at solar phases 8-11 degrees. Mutual
eclipse/occultation events that are 0.07 to 0.15 magnitude deep indicate a
secondary-to-primary mean-diameter ratio of 0.26 ± 0.02. The secondary
appears synchronous and has a light-curve amplitude (in the combined primary
plus secondary light curve) of 0.02 mag, suggesting a moderately elongated
shape with the equatorial axis ratio of 1.3 ± 0.1.

http://www.cbat.eps.harvard.edu/cbet/RecentCBETs.html

Despite many decades of minor planet studies focused
on external and dynamical properties, there are still
hundreds of asteroids that have never been measured.
Presented here are the results of photometric analysis
applied to five main-belt asteroids. In addition to
calculating rotation period, axis ratios assuming a simple
ellipsoidal shape and the estimated minimum density of
each asteroid are reported.

2017MPBu___44__276A

Associated tables:

IAU CBET nº4523

(15745) YULIYA
A. Aznar, Observatorio Isaac Aznar, Aras de los Olmos, Spain;
O. Vaduvescu, Isaac Newton Group (ING) and Instituto de Astrofisica de
Canarias (IAC), Spain; T. Wilson, Isaac Newton Group (ING), University
College London (UCL), U.K.; T. Zegmott, Isaac Newton Group (ING),
University of Kent, U.K., and P. Pravec, Ondrejov Observatory, report
that photometric observations taken within the European Near Earth
Asteroids Research (EURONEAR) program with a 1.2-m telescope at the
Mercator Observatory, La Palma, Canary Island, Spain, during
Apr. 26-May 6 reveal that minor planet (15745) is a binary system with
an orbital period of 15.63 +/- 0.02 hr.  The primary shows a period of
3.2486 +/- 0.0003 hr and has a lightcurve amplitude of 0.10 mag at solar
phases 35.1-35.2 degrees, suggesting a nearly spheroidal shape.  Mutual
eclipse/occultation events that are 0.15- to 0.21-magnitude deep indicate
a lower limit on the secondary-to-primary mean-diameter ratio of 0.43.

IAU CBET nº4517:

(17700) 1953 XU_1 = 1997 GM_40 = 1999 VD_53

D. Pray, Sugarloaf Mountain Observatory, South Deerfield, MA, U.S.A.;
P. Pravec, H. Kucakova, K. Hornoch, and P. Kusnirak, Ondrejov Observatory;
J. Oey, Blue Mountains Observatory, Leura, NSW, Australia; V. Benishek,
Belgrade Astronomical Observatory; A. Aznar, Astronomia Para Todos
Observatories Group, «European Near Earth Asteroids Research (EURONEAR)»,
Spain; and A. L. Comazzi, Instituto de Astrofisica de Andalucia, CSIC,
Spain, report that photometric observations obtained with a 0.50-m
telescope at the Sugarloaf Mountain Observatory, a 0.65-m telescope at the
Ondrejov Observatory, a 0.61-m, a 0.35-m and a 0.31-m telescopes at the
Blue Mountains Observatory, a 0.35-m telescope at the Sopot Observatory in
Serbia, and a 0.90-m telescope at Sierra Nevada Observatory during
Mar. 20-May 10 reveal that minor planet (17700) is a binary system with an
orbital period of 15.49 ± 0.02 hr. The primary shows a period of 3.8382
± 0.0002 hr and has a lightcurve amplitude of 0.13 mag at solar phases
8-15 degrees, suggesting a nearly spheroidal shape. Mutual
eclipse/occultation events that are up to 0.20-magnitude deep indicate a
lower limit on the secondary-to-primary mean-diameter ratio of 0.31.
There occurred two additional 0.14- to 0.18-magnitude-deep attenuations on
Mar. 20 and 25 that were not aligned with the 15.49-hr orbital period,
suggesting presence of a third body in the system. The mean absolute
magnitude of the whole system in the Cousins R photometric system is H_R =
13.98 ± 0.05 with the phase relation slope parameter G = 0.35 ± 0.05.