J/ApJS/241/6 Searching for super-fast rotators using PS1 (Chang+, 2019)
Searching for super-fast rotators using the Pan-STARRS 1.
Chang C.-K., Lin H.-W., Ip W.-H., Chen W.-P., Yeh T.-S., Chambers K.C.,
Magnier E.A., Huber M.E., Flewelling H.A., Waters C.Z., Wainscoat R.J.,
Schultz A.S.B.
<Astrophys. J. Suppl. Ser., 241, 6 (2019)>
=2019ApJS..241....6C 2019ApJS..241....6C
ADC_Keywords: Minor planets; Photometry, SDSS; Magnitudes, absolute
Keywords: minor planets, asteroids: general ; surveys
Abstract:
A class of asteroids, called large super-fast rotators (large SFRs),
have rotation periods shorter than 2hr and diameters larger than
∼0.3km. They pose challenges to the usual interior rubble-pile
structure unless a relatively high bulk density is assumed. So far,
only six large SFRs have been found. Therefore, we present a survey of
asteroid rotation periods using the Panoramic Survey Telescope and
Rapid Response System (Pan-STARRS) 1 telescope during 2016 October
26-31 to search for more large SFRs and to study their properties. A
total of 876 reliable rotation periods are measured, among which seven
are large SFRs, thereby increasing the inventory of known large SFRs.
These seven newly discovered large SFRs have diverse colors and
locations in the main asteroid belt, suggesting that the taxonomic
tendency and the location preference in the inner main belt of the six
previously known large SFRs could be a bias due to various
observational limits. Interestingly, five out of the seven newly
discovered large SFRs are mid main-belt asteroids (MBAs). Considering
the rare discovery rates of large SFR in the previously similar
surveys and the survey condition in this work, the chance of detecting
a large SFR in the inner main belt seems to be relatively low. This
probably suggests that the inner main belt harbors fewer large SFRs
than the mid main belt. From our survey, we also found a drop in the
number appearing at f>5rev/day on the spin-rate distribution for the
outer MBAs of D<3km, which was reported for the inner and mid main
belt by Chang et al. (2015, J/ApJS/219/27 ; 2016ApJ...816...71C 2016ApJ...816...71C).
Description:
The Pan-STARRS 1 (PS1) was designed to explore the visible 3π sky
and is mainly dedicated to finding small solar system bodies,
especially those potentially hazardous objects. The telescope is a
1.8m RitcheyChretien reflector located on Haleakala, Maui, which is
equipped with the Gigapixel Camera #1 to create a field of view of
7deg2. The available filters include gP1 (∼400-550nm), rP1
(∼550-700nm), iP1 (∼690-820nm), zP1 (∼820-920nm), and yP1
(>920nm), and a special filter, wP1 (i.e., combination of gP1,
rP1, and iP1), was designed for the discovery of moving object.
We used the PS1 to conduct a special campaign to collect asteroid
light curves in the wP1 band during 2016 October 26-31, in which
eight consecutive PS1 fields (i.e., ∼56deg2 in total) over the
ecliptic plane around the opposition were continuously scanned using a
cadence of ∼10min.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 130 876 The 876 reliable rotation periods
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See also:
J/ApJ/742/40 : Jovian Trojans asteroids with WISE/NEOWISE (Grav+, 2011)
J/ApJ/743/156 : NEOWISE obs. of NEOs: preliminary results (Mainzer+, 2011)
J/ApJ/741/68 : Main Belt asteroids with WISE/NEOWISE. I. (Masiero+, 2011)
J/ApJ/750/99 : The Pan-STARRS1 photometric system (Tonry+, 2012)
J/ApJS/219/27 : Surveys of asteroid rotation periods using iPTF (Chang+, 2015)
J/AJ/150/75 : Asteroid light curves from PTF survey (Waszczak+, 2015)
J/ApJS/227/20 : Rotation periods of asteroids using iPTF (Chang+, 2016)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- ID Compact object identifier (asteroid number or
MPC packed format)
10 A1 --- f_ID [ab] Flag on ID (1)
12- 17 I6 -- Planet [1489/399139]? Asteroid number
19- 33 A15 --- Name Name or preliminary designation
35- 38 F4.2 AU a [1.8/4] Semi-major axis
40- 43 F4.2 --- e [0.01/0.5] Eccentricity
45- 48 F4.1 deg i [0.3/32] Inclination
50- 52 F3.1 AU Delta [4.9/8] Mean heliocentric distance
54- 56 F3.1 AU r [4.9/8] Mean geodesic distance
58- 60 F3.1 deg alpha [4.9/8] Mean phase angle
62- 65 F4.1 km Diam [0.2/28.5] Diameter
67- 71 F5.2 mag HMag [11.7/20.5] Absolute magnitude
73- 76 F4.2 mag e_HMag [0.03/0.5] Uncertainty in HMag
78- 82 F5.2 mag mag [12/22] Apparent magnitude in PS1 wP1 filter
84- 87 F4.2 mag e_mag [0/0.2] Uncertainty in mag
89- 94 F6.2 h Per [0.5/126.4] Derived rotation period
96- 99 F4.2 h e_Per [0/9.3] Uncertainty in P
101-104 F4.2 mag Deltam [0.09/1.5] Light-curve amplitude
106 I1 --- U [2/3] Rotation period quality code
(3=highly reliable; 2=some ambiguity)
108-112 F5.2 --- a* [-5.6/3.1]? SDSS color a* (2)
114-117 F4.2 --- e_a* [0/0.6]? Uncertainty in a*
119-123 F5.2 --- i-z [-2.4/2]? SDSS (i-z) color index
125-128 F4.2 --- e_i-z [0/1.4]? Uncertainty in i-z
130 A1 --- Type Spectral type ("C"=385 occurrences,
"S"=248 occurrences or "V"=128 occurrences)
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Note (1): Flag as follows:
a = Rotation period measurements available in the LCDB.
b = Long-period objects with partial coverage on rotational phase.
Note (2): Where a*=0.89*(g-r)+0.45*(r-i)-0.57.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 27-May-2019