J/ApJS/244/19 OSSOS. XII. Subaru/HSC obs. of 65 TNOs (Alexandersen+, 2019)
OSSOS.
XII. Variability studies of 65 trans-Neptunian objects using the Hyper
Suprime-Cam.
Alexandersen M., Benecchi S.D., Chen Y.-T., Eduardo M.R., Thirouin A.,
Schwamb M.E., Lehner M.J., Wang S.-Y., Bannister M.T., Gladman B.J.,
Gwyn S.D.J., Kavelaars JJ., Petit J.-M., Volk K.
<Astrophys. J. Suppl. Ser., 244, 19 (2019)>
=2019ApJS..244...19A 2019ApJS..244...19A
ADC_Keywords: Minor planets; Photometry, RI; Magnitudes, absolute
Keywords: Kuiper belt: general ; minor planets, asteroids: general ;
planets and satellites: surfaces
Abstract:
We present variability measurements and partial light curves of
trans-Neptunian objects (TNOs) from a two-night pilot study using
Hyper Suprime-Cam (HSC) on the Subaru Telescope (Maunakea, Hawaii,
USA). Subaru's large aperture (8m) and HSC's large field of view
(1.77deg2) allow us to obtain measurements of multiple objects with
a range of magnitudes in each telescope pointing. We observed 65
objects with mr=22.6-25.5mag in just six pointings, allowing 20-24
visits of each pointing over the two nights. Our sample, all
discovered in the recent Outer Solar System Origins Survey (OSSOS),
spans absolute magnitudes of Hr=6.2-10.8mag and thus investigates
smaller objects than previous light curve projects have typically
studied. Our data supports the existence of a correlation between the
light curve amplitude and absolute magnitude seen in other works but
does not support a correlation between the amplitude and orbital
inclination. Our sample includes a number of objects from different
dynamical populations within the trans-Neptunian region, but we do not
find any relationship between variability and the dynamical class. We
were only able to estimate periods for 12 objects in the sample and
found that a longer baseline of observations is required for a
reliable period analysis. We find that 31 objects (just under half of
our sample) have variability of Δmag greater than 0.4mag
during all of the observations; in smaller 1.25hr, 1.85hr, and 2.45hr
windows, the median Δmag is 0.13, 0.16, and 0.19mag,
respectively. The fact that variability on this scale is common for
small TNOs has important implications for discovery surveys (such as
OSSOS or the Large Synoptic Survey Telescope) and color measurements.
Description:
The Outer Solar System Origins Survey (OSSOS; Bannister+ 2016, J/AJ/152/70
and 2018, J/ApJS/236/18) was a large program on the Canada-France-Hawaii
Telescope (CFHT), which ran from 2013 through 2017. OSSOS detected and
tracked more than 800 trans-Neptunian objects with regular follow-up
observations during at least two years.
A total of 63 TNOs (37 classical, 15 resonant, 5 detached, and 6
scattering) and two Centaurs were observed on the nights of 2016
August 25 and 26, using the Hyper Suprime-Cam (HSC) on Subaru
Telescope, located on Maunakea, Hawaii, USA.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 119 65 Summary of information about the objects in our sample
table3.dat 56 1182 Photometric measurements from this Subaru/HSC data set
table6.dat 46 12 Best periods from two methods
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See also:
J/AJ/127/3023 : R magnitudes of Kuiper Belt object 2001QG298 (Sheppard+, 2004)
J/A+A/505/1283 : (84922) 2003 VS2 differential light curve (Duffard+, 2009)
J/A+A/522/A93 : Short-term variability of 29 minor planets (Thirouin+, 2010)
J/ApJS/189/336 : HST astrometry of TNOs (Benecchi+, 2010)
J/ApJ/750/99 : The Pan-STARRS1 photometric system (Tonry+, 2012)
J/A+A/569/A3 : Rotational properties of TNOs (Thirouin+, 2014)
J/A+A/584/A96 : Observations of 50 TNOs and Centaurs (Desmars+, 2015)
J/AJ/152/111 : A 2011-2013 survey of TNOs (Alexandersen+, 2016)
J/AJ/152/70 : Outer Solar System Origins Survey (OSSOS) (Bannister+, 2016)
J/AJ/153/116 : Trojan asteroids in the Kepler campaign 6 field (Ryan+, 2017)
J/AJ/154/241 : Photom. of a Kuiper Belt object: 2002CC249 (Thirouin+, 2017)
J/AJ/156/33 : Resonance sticking in the pop. of scattering TNOs (Yu+, 2018)
J/ApJS/236/18 : OSSOS. VII. TNOs complete data release (Bannister+, 2018)
J/AJ/157/120 : TNOs & Centaurs observed within the DES (Banda-Huarca+, 2019)
J/AJ/157/228 : Cold Classical TNOs: LCs & rotational data (Thirouin+, 2019)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- ID Internal OSSOS designation;
see Bannister+ (2018, J/ApJS/236/18)
9- 12 A4 --- Field Field in which the target was observed (1)
14- 20 F7.3 au a [21.9/200.2] Barycentric semi-major axis
22- 27 F6.4 au e_a [0.001/0.5] Uncertainty in a
29- 33 F5.3 --- e [0.01/0.8] Barycentric eccentricity (2)
35- 40 F6.3 deg i [0.4/40.4] Barycentric orbital inclination (2)
42- 50 A9 --- Class Dynamical classification of the object
52- 63 A12 --- MPC Minor Planet Center designation
65- 70 F6.3 mag mrmag [22.6/25.7] Mean apparent magnitude, in mr-band
72- 76 F5.3 mag e_mrmag [0.002/0.02] Uncertainty in mrmag
78- 83 F6.3 mag HrMag [6/11] Mean absolute magnitude, in Hr-band
85- 89 F5.3 mag dmag [0.1/1.1] Maximum variation of magnitudes
measured in this work
91- 95 F5.3 mag e_dmag [0.01/0.09] Lower uncertainty on dmag
97-101 F5.3 mag E_dmag [0.01/0.1] Upper uncertainty on dmag
103-107 F5.3 mag smag [0.02/0.3] Standard deviation of the magnitudes
measured in this work
109-113 F5.3 mag e_smag [0.002/0.02] Lower uncertainty on dmag
115-119 F5.3 mag E_smag [0.002/0.02] Upper uncertainty on dmag
--------------------------------------------------------------------------------
Note (1): Field defined in Table 1 as:
-----------------------------------------------------------------
Field RA DE Obs. Night1 Obs. Night 2
h:m:s deg:':" Useful/Total Useful/Total
-----------------------------------------------------------------
LF07 00:31:33 +04:54:54 12/12 10/12
LF08 00:41:41 +05:17:52 12/12 10/12
LF09 00:42:34 +06:37:44 12/12 10/12
LF10 00:45:37 +07:59:02 12/12 10/12
LF11 01:10:00 +05:43:25 10/10 9/10
LF12 01:21:51 +06:34:20 10/10 9/10
-----------------------------------------------------------------
Note. On the second night, each field lost one or two
observations due to low transparency.
-----------------------------------------------------------------
Note (2): Uncertainties on eccentricity and inclination are always 0.001 or
smaller.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- ID Internal OSSOS designation;
see Bannister+ (2018, J/ApJS/236/18)
9- 20 A12 --- MPC Minor Planet Center designation
22- 30 F9.7 d MJD [6.3/7.7] Modified Julian Date, MJD-57620
32- 37 F6.3 mag mrmag [22.5/26.2] Magnitude measurement in r-band
39- 43 F5.3 mag e_mrmag [0.007/0.2] Random uncertainty in mrmag
45- 50 F6.3 mag Zpt [26.4/27.3] Zero-point used
52- 56 F5.3 mag e_Zpt [0.003/0.02] Systematic uncertainty on
the zero-point
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- MPC Minor Planet Center designation
14- 18 F5.2 h LCPer-PDM [6/20.3] Light curve period, PDM method (1)
20- 23 F4.2 h e_LCPer-PDM [0.02/0.3] Uncertainty in Per-PDM
25- 29 F5.1 % pPDM [30.3/100] Percent best period, PDM (2)
31- 35 F5.2 h LCPer-PDS [6/20.3] Light curve period, PDS method (1)
37- 40 F4.2 h e_LCPer-PDS [0.03/0.2] Uncertainty in Per-PDS
42- 46 F5.1 % pPDS [41.3/100] Percent best light curve period,
PDS (2)
--------------------------------------------------------------------------------
Note (1): As these objects are small, their variability is most likely
shape-dominated; shape dominated light curves have two peaks per
rotation of the object. These periods have thus been doubled to represent
the rotation period of the object.
Note (2): Percentage of resampled light curves that had a "best" light curve
period within 5σ of the reported value. Only objects where the two
methods agree on the best light curve period are included.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
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Shankman et al. Paper II. 2016AJ....151...31S 2016AJ....151...31S
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Bannister et al. Paper V. 2017AJ....153..262B 2017AJ....153..262B
Shankman et al. Paper VI. 2017AJ....154...50S 2017AJ....154...50S
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(End) Prepared by [AAS], Emmanuelle Perret [CDS] 18-Feb-2020