J/ApJ/749/10 SDSS observations of Kuiper belt objects (Ofek, 2012)
Sloan Digital Sky Survey observations of Kuiper belt objects: colors and
variability.
Ofek E.O.
<Astrophys. J., 749, 10 (2012)>
=2012ApJ...749...10O 2012ApJ...749...10O
ADC_Keywords: Photometry, SDSS ; Minor planets
Keywords: Kuiper belt: general - planetary systems - techniques: photometric
Abstract:
Colors of trans-Neptunian objects (TNOs) are used to study the
evolutionary processes of bodies in the outskirts of the solar system
and to test theories regarding their origin. Here I describe a search
for serendipitous Sloan Digital Sky Survey (SDSS) observations of
known TNOs and Centaurs. I present a catalog of SDSS photometry,
colors, and astrometry of 388 measurements of 42 outer solar system
objects. I find weak evidence, at the ~ 2σ level (per
trial), for a correlation between the g - r color and inclination of
scattered disk objects and hot classical Kuiper Belt objects. I find a
correlation between the g - r color and the angular momentum in the z
direction of all the objects in this sample. These findings should be
verified using larger samples of TNOs. Light curves as a function of
phase angle are constructed for 13 objects. The steepness of the
slopes of these light curves suggests that the coherent backscatter
mechanism plays a major role in the reflectivity of outer solar system
small objects at small phase angles. I find weak evidence for an
anticorrelation, significant at the 2σ confidence level (per
trial), between the g-band phase-angle slope parameter and the
semimajor axis, as well as the aphelion distance, of these objects
(i.e., they show a more prominent "opposition effect" at smaller
distances from the Sun). However, this plausible correlation should be
verified using a larger sample. I discuss the origin of this possible
correlation and argue that if this correlation is real it probably
indicates that "Sedna"-like objects have a different origin than other
classes of TNOs. Finally, I identify several objects with large
variability amplitudes.
Description:
I retrieved a list of the orbital elements of all known (numbered and
unnumbered) minor planets in the solar system from the Jet Propulsion
Laboratory (JPL) Horizons system (updated for 2010 August 2). I used
the SDSS (York et al. 2000AJ....120.1579Y 2000AJ....120.1579Y) CasJobs utility to generate
a catalog of all the images that are available in the SDSS database.
The catalog contains all the images included in the SDSS data release
7 (DR7), Segue, and Stripe 82 (Abazajian et al. 2009, Cat. II/294).
I cross-correlate SDSS observations with the ephemerides of
solar-system bodies with a > 10 AU. I present a catalog of SDSS
photometric and astrometric measurements of such minor planets based
on SDSS observations. After removing possible contaminated
measurements, I am left with 388 observations of 42 unique objects.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 83 388 Astrometric measurements of solar system objects
identified in SDSS images
table2.dat 113 388 Photometric properties of solar system objects
identified in SDSS images
table3.dat 106 42 Mean photometric properties of outer solar
system objects identified in SDSS images
--------------------------------------------------------------------------------
See also:
B/astorb : Orbits of Minor Planets (Bowell+ 2013)
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 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/A+A/508/451 : Light curves of 5 Trans-Neptunian Objects (Perna+, 2009)
J/AJ/133/26 : Solar phase curves of distant icy bodies (Rabinowitz+, 2007)
J/A+A/468/L13 : Photometry of the trans-Neptunian object 2005FY9 (Ortiz+, 2007)
http://www.sdss.org/ : SDSS home page
http://www.minorplanetcenter.net/ : Minor Planet Center home page
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- ID Minor planet number or provisional designation
12- 22 F11.6 d ODate [1081.82/4466.71] Julian Date of r' band
observation; JD-2450000
24- 27 I4 --- Run SDSS run number (1)
29- 30 I2 --- ReRun SDSS rerun number (1)
32 I1 --- CamCol SDSS camcol number (1)
34- 36 I3 --- Field SDSS field number (1)
38- 47 F10.6 deg RAdeg Observed SDSS Right Ascension in decimal
degrees (J2000)
49- 57 F9.6 deg DEdeg Observed SDSS Declination in decimal
degrees (J2000)
59- 68 F10.6 deg RAPdeg Predicted SDSS Right Ascension in decimal
degrees (J2000)
70- 78 F9.6 deg DEPdeg Predicted SDSS Declination in decimal
degrees (J2000)
80- 83 F4.2 arcsec Dist [0.01/1.48] Angular distance between observe
and predicted position
--------------------------------------------------------------------------------
Note (1): Identifies the unique SDSS ugriz image.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- ID Minor planet number or provisional designation
12- 22 F11.6 d ODate [1081.82/4466.71] Julian Date of r' band
observation; JD-2450000
24- 29 F6.3 AU R [8.7/49.1] Heliocentric distance
31- 36 F6.3 AU Delta [8.6/48.2] Geocentric distance Δ
38- 41 F4.2 deg beta [0.08/6.46] Phase angle β
43- 46 F4.1 mag Vmag [19.2/22] Predicted V-band magnitude at
time of SDSS observation
48 I1 --- Type [3/6] SDSS type; 6-star, 3-galaxy
50- 55 F6.3 mag umag [20.82/22.14]? SDSS u-band magnitude (1)
57- 62 F6.3 mag gmag [19.39/22.96]? SDSS g-band magnitude (1)
64- 69 F6.3 mag rmag [18.89/22.59] SDSS r-band magnitude (1)
71- 76 F6.3 mag imag [18.79/22.26]? SDSS i-band magnitude (1)
78- 83 F6.3 mag zmag [18.72/21.01]? SDSS z-band magnitude (1)
85- 89 F5.3 mag e_umag ? SDSS u-band magnitude error (1)
91- 95 F5.3 mag e_gmag ? SDSS g-band magnitude error (1)
97-101 F5.3 mag e_rmag SDSS r-band magnitude error (1)
103-107 F5.3 mag e_imag SDSS i-band magnitude error (1)
109-113 F5.3 mag e_zmag ? SDSS z-band magnitude error (1)
--------------------------------------------------------------------------------
Note (1): In cases in which the error magnitudes are larger than 0.2 mag, I
replaced the SDSS magnitude with blanks. However, I kept the errors in
the table. Note that the absolute planetary r-band magnitude of
measurement number 18 of object 145452, measurement number 7 of object
145453, and measurement number 13 of object 145480 deviate by more
than one magnitude from the median absolute planetary magnitude and
are probably bad measurements. These measurements are listed in this
table but are not used in the subsequent analysis (e.g., they are not
shown in Figure 3 and they are excluded from the phase-angle slope
parameter fits summarized in Table 4).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- ID Minor planet designation
12 A1 --- f_ID [HCO] Name: H=Huya, C=Ceto, O=Orcus
14- 15 I2 --- Nobs [1/49] Number of r-band observations in table2
17- 21 F5.3 mag Hu [4.11/5.996]? Median absolute planetary u-band
magnitude, not corrected for phase angle
23- 28 F6.3 mag Hg [2.702/12.511]? Median absolute planetary
g-band magnitude, not corrected for phase angle
30- 35 F6.3 mag Hr [2.222/12.296] Median absolute planetary
r-band magnitude, not corrected for phase angle
37- 42 F6.3 mag Hi [2.082/11.961]? Median absolute planetary
i-band magnitude, not corrected for phase angle
44- 49 F6.3 mag Hz [2.054/10.067]? Median absolute planetary
z-band magnitude, not corrected for phase angle
51- 55 F5.3 mag e_Hu [0/0.331]? Standard deviation in Hu (2)
57- 61 F5.3 mag e_Hg [0/0.245]? Standard deviation in Hg (2)
63- 67 F5.3 mag e_Hr [0/0.504] Standard deviation in Hr (2)
69- 73 F5.3 mag e_Hi [0/0.409]? Standard deviation in Hi (2)
75- 79 F5.3 mag e_Hz [0/0.199]? Standard deviation in Hz (2)
81- 85 F5.3 mag DHr [0/0.852] Range in Hr over all measurements,
excluding the three bad measurements
87- 93 F7.3 AU amaj [12.632/549.606] Semimajor axis
95- 99 F5.3 --- e [0.008/0.935] Orbital eccentricity
101-106 F6.3 deg i [1.837/41.698] Orbital inclination
--------------------------------------------------------------------------------
Note (2): Standard deviation (StD) after removing the three bad
measurements (see Note (1) of table 2).
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 06-Nov-2013