J/AJ/152/221 New extreme trans-Neptunian objects (Sheppard+, 2016)
New extreme trans-Neptunian objects: toward a super-Earth in the outer solar
system.
Sheppard S.S., Trujillo C.
<Astron. J., 152, 221-221 (2016)>
=2016AJ....152..221S 2016AJ....152..221S (SIMBAD/NED BibCode)
ADC_Keywords: Solar system ; Minor planets ; Magnitudes ; Surveys
Keywords: comets: general - Kuiper belt: general -
minor planets, asteroids: general - Oort Cloud -
planets and satellites: individual: Sedna, 2012 VP113
Abstract:
We are performing a wide and deep survey for extreme distant solar
system objects. Our goal is to understand the high-perihelion objects
Sedna and 2012 VP113 and determine if an unknown massive planet exists
in the outer solar system. The discovery of new extreme objects from
our survey of some 1080 square degrees of sky to over 24th magnitude
in the r-band are reported. Two of the new objects, 2014 SR349 and
2013 FT28, are extreme detached trans-Neptunian objects, which have
semimajor axes greater than 150 au and perihelia well beyond Neptune
(q>40au). Both new objects have orbits with arguments of perihelia
within the range of the clustering of this angle seen in the other
known extreme objects. One of these objects, 2014 SR349, has a
longitude of perihelion similar to the other extreme objects, but 2013
FT28 is about 180° away or anti-aligned in its longitude of
perihelion. We also discovered the first outer Oort Cloud object with
a perihelion beyond Neptune, 2014 FE72. We discuss these and other
interesting objects discovered in our ongoing survey. All the high
semimajor axis (a>150au) and high-perihelion (q>35au) bodies follow
the previously identified argument of perihelion clustering as first
reported and explained as being from an unknown massive planet in 2014
by Trujillo & Sheppard, which some have called Planet X or Planet
Nine. With the discovery of 2013 FT28 on the opposite side of the sky,
we now report that the argument of perihelion is significantly
correlated with the longitude of perihelion and orbit pole angles for
extreme objects and find there are two distinct extreme clusterings
anti-aligned with each other. This previously unnoticed correlation is
further evidence of an unknown massive planet on a distant eccentric
inclined orbit, as extreme eccentric objects with perihelia on
opposite sides of the sky (180° longitude of perihelion
differences) would approach the inclined planet at opposite points in
their orbits, thus making the extreme objects prefer to stay away from
opposite ecliptic latitudes to avoid the planet (i.e., opposite
argument of perihelia or orbit pole angles).
Description:
The majority of the area surveyed was with the Cerro Tololo
Inter-American Observatory (CTIO) 4m Blanco telescope in Chile with
the 2.7 square degree Dark Energy Camera (DECam). DECam has 62
2048*4096 pixel CCD chips from Lawrence Livermore Berkeley Labs with a
scale of 0.26arcsec per pixel. The r-band filter was used during the
early observing runs (2012 November and December and 2013 March, May,
and November) and the ultra-wide VR filter was used in the later
observations (2014 March and September and 2015 April).
Before DECam became operational, the initial IOC survey was begun
using the 0.255 square degree SuprimeCam on the 8m Subaru telescope,
the 0.16 square degree IMACS on the 6.5m Magellan telescope, and the
0.36 square degree Mosaic-1.1 on the Kitt Peak National Observatory
(KPNO) 4m Mayall telescope. The observing nights and conditions of the
survey fields are shown in Table1.
Usable survey data required no significant extinction from clouds and
seeing less than 1.5 arcsec at the CTIO 4m and KPNO 4m. In general,
the exposure times were set to reach the 24th magnitude with the
r-band filter and 24.5 magnitude with the VR filter during the night.
In the best seeing of 0.8 arcsec, integration times were around 330s,
while in the worst seeing exposure times were up to 700s. This allowed
our survey to obtain a similar depth regardless of the seeing
conditions. The Subaru and Magellan observations went deeper, with the
target depth of around 25.5 magnitudes in the r-band and useful seeing
being less than 1.0 arcsec.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 69 904 Inner Oort Cloud survey observations
table2.dat 72 7 New extreme distant solar system objects
table3.dat 64 19 Stability of extreme trans-Neptunian objects
table4.dat 66 5 Other new interesting distant solar system objects
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See also:
B/astorb : Orbits of Minor Planets (Bowell+ 2014)
J/ApJ/720/1691 : Observations of the distant Kuiper belt (Schwamb+, 2010)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "Y:M:D" Date Date of the observation
12- 19 A8 --- Inst Instrument used to obtain the data (CTIO4m,
KPNO4m, Magellan, or Subaru) (1)
21- 24 F4.1 h T [1/48] Amount of time between first and last
field images
26- 29 F4.2 arcsec Seeing [0.5/1.5] Average seeing for the night (θ)
31- 34 F4.1 mag rlim [23.3/25.7] Limiting magnitude in the r-band (2)
36- 39 F4.1 deg2 Area [0.5/62.1] Survey image area
41- 49 A9 --- Field Field name used at the telescope
51- 52 I2 h RAh Hour of Right Ascension (J2000)
54- 55 I2 min RAm Minute of Right Ascension (J2000)
57- 58 I2 s RAs Second of Right Ascension (J2000)
60 A1 --- DE- Sign of the Declination (J2000)
61- 62 I2 deg DEd Degree of Declination (J2000)
64- 65 I2 arcmin DEm Arcminute of Declination (J2000)
67- 69 I3 arcsec DEs Arcsecond of Declination (J2000)
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Note (1): The facilities used are defined as follows:
Subaru = The 0.255 square degree SuprimeCam on the 8m Subaru telescope;
Magellan = The 0.16 square degree Inamori-Magellan Areal Camera and
Spectrograph (IMACS) on the 6.5m Magellan telescope;
KPNO4m = The 0.36 square degree MOSAIC-1.1 on the Kitt Peak National
Observatory (KPNO) 4m Mayall telescope;
CTIO4m = The 2.7 square degree Dark Energy Camera (DECam) on Cerro Tololo
Inter-American Observatory (CTIO) 4m Blanco telescope in Chile;
Note (2): In the r-band where we would have found at least 50% of the slow
moving objects in the field.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- Gr Group (G1)
5- 14 A10 --- Name Object name
16- 19 F4.1 AU q [34.5/80.3] Perihelion (1)
21- 24 I4 AU a [143/2155] Semimajor axis (1)
26- 30 F5.3 --- e [0.68/0.98] Eccentricity (1)
32- 37 F6.3 deg i [13.07/48.24] Inclination (1)
39- 45 F7.3 deg Omega [34.9/336.84] Longitude of the ascending node
(Ω) (1)
47- 52 F6.2 deg omega [40.7/341.2] Argument of perihelion (ω) (1)
54- 57 F4.1 deg ELAT [2/17.1] Ecliptic latitude at discovery (b)
59- 62 F4.1 AU Dist [52.1/87.9] Distance at discovery
64- 66 I3 km Diam [125/550] Diameter estimate assuming a moderate
albedo of 0.10
68- 72 F5.2 mag rmag [23.35/24.8] The r-band magnitude (mr)
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Note (1): Uncertainties are shown by the number of significant digits.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- Gr Group (G1)
5- 14 A10 --- Name Object name
16- 20 F5.2 AU q [33.16/80.27] Perihelion (1)
22- 24 I3 AU a [151/499] Semimajor axis (1)
26- 29 F4.2 --- e [0.69/0.93] Eccentricity (1)
31- 34 F4.1 deg i [4.5/33.5] Inclination (1)
36- 40 F5.1 deg Omega [24.4/306.1] Longitude of the ascending node
(Ω) (1)
42- 46 F5.1 deg omegA [7/354.9] Argument of perihelion (ω) (1)
48- 52 F5.1 deg omegL [2.7/338.4] Longitude of perihelion (ω) (1)
54- 55 I2 yr Nyr [0/13] Number of years observed
57- 59 A3 --- Stable Stability (Yes or No) (2)
60 A1 --- u_Stable [:] Uncertainty flag on Stable
61- 64 A4 --- f_Stable Flag on Stable (MMR? or Res?) (3)
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Note (1): Orbits are from the Minor Planet Center (MPC) as of 2016 July.
Note (2): Stability is defined as follows:
Yes = An object is considered stable if it moved less than a few au in
semimajor axis during our 1 billion year numerical integrations using
only the known 8 major planets;
No = All unstable objects had well over 100au changes in their semimajor
axes within 1 billion years, with most lost within about 1 billion
years including 2010 VZ98 and 2007 TG422.
Note (3): Flag for interaction or resonance with Neptune is defined as follows:
MMR? = 2000 CR105 and 2005 RH52 showed stable semimajor axes, but the
stepped motion of a over time suggests they could be in a Mean
Motion Resonance (MMR) with Neptune;
Res? = 2013 FT28 also had some jumpiness in its semimajor axis, usually
about 10au for the nominal and 1σ clones orbits, suggesting
some significant resonant interactions with Neptune
(see Section 4.2.1 in the text).
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Object name
12- 13 I2 AU q [34/39] Perihelion (1)
15- 17 I3 AU a [79/103] Semimajor axis (1)
19- 22 F4.2 --- e [0.54/0.63] Eccentricity (1)
24- 28 F5.2 deg i [15.2/35.8] Inclination (1)
30- 35 F6.2 deg Omega [19.8/356.6] Longitude of the ascending node
(Ω) (1)
37- 42 F6.2 deg omega [46.6/259] Argument of perihelion (ω) (1)
44- 47 F4.1 AU Dist [48.2/69.3] Distance at discovery
49- 51 I3 km Diam [100/300] Diameter estimates assuming a moderate
albedo of 0.10
53- 56 F4.1 mag rmag [23.9/24.7] The r-band magnitude (mr)
58- 66 A9 --- N:N Location near Neptune mean motion resonance
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Note (1): The uncertainty of the orbital elements for each object is shown by
the number of significant digits.
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Global Notes:
Note (G1): The definitions of the various groupings are explained as follows:
IOC = Inner Oort Cloud (q>50 and 150<a<1000au);
OOC = Outer Oort Cloud (q>35au and a>1500au);
EDO = Extreme Detached Object (40<q<50 and 150<a<1000au);
DO = Detached/Mean Motion Resonance+Kozai Resonance (MMR+KR) Object
(q>40 and 50<a<150au);
ESO = Extreme Scattered Object (30<q<40 and 150<a<1000au).
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History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 08-Feb-2017