J/AJ/159/25 PS1 light curves and rotation periods of new asteroids (Lo+, 2020)
Asteroid discovery and light curve extraction using the Hough transform: a
rotation period study for subkilometer main-belt asteroids.
Lo K.-J., Chang C.-K., Lin H.-W., Tsai M.-F., Ip W.-H., Chen W.-P.,
Yeh T.-S., Chambers K.C., Magnier E.A., Huber M.E., Wainscoat R.J.
<Astron. J., 159, 25 (2020)>
=2020AJ....159...25L 2020AJ....159...25L
ADC_Keywords: Minor planets; Magnitudes, absolute; Photometry, ugriz;
Surveys
Keywords: Period determination ; Surveys ; Light curves ; Asteroids ;
Main belt asteroids ; Astronomical methods
Abstract:
The intranight trajectories of asteroids can be approximated by
straight lines, and so are their intranight detections. Therefore, the
Hough transform, a line detecting algorithm, can be used to connect
the line-up detections to find asteroids. We applied this algorithm to
a high-cadence Pan-STARRS 1 (PS1) observation, which was originally
designed to collect asteroid light curves for rotation period
measurements. The algorithm recovered most of the known asteroids in
the observing fields and, moreover, discovered 3574 new asteroids with
magnitude mainly of 21.5<wp1<22.5mag. This magnitude range is
equivalent to subkilometer main-belt asteroids (MBAs), which usually
lack rotation period measurements due to their faintness. Using the
light curves of the 3574 new asteroids, we obtained 122 reliable
rotation periods, of which 13 are super-fast rotators (SRFs; i.e.,
rotation period of <2hr). The required cohesion to survive these SFRs
range from tens to thousands of Pa, a value consistent with the known
SFRs and the regolith on the Moon and Mars. The higher chance of
discovering SFRs here suggests that subkilometer MBAs probably harbor
more SFRs.
Description:
During 2016 October 26-31, a high-cadence observation was carried out
using Pan-STARRS 1 (PS1) to collect a large sample of asteroid light
curves for a rotation period measurement (Chang+, 2019, J/ApJS/241/6).
The observation was conducted using a cadence of ∼10 minutes to
repeatedly scan eight consecutive PS1 fields in the wP1 band
(i.e., combination of gP1, rP1, and iP1). Moreover, several
exposures in each gP1 (∼400-550nm), rP1 (∼550-700nm),
iP1 (∼690-820nm), and zP1 (∼820-920nm) band were also taken in the
first night between the exposures of the wP1 band to obtain asteroid
colors. Table 1 shows the summary of the observation.
The source catalogs obtained from this high-cadence observation were
used as our running cases for the Hough transform algorithm.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 53 8 Pan-STARRS 1 (PS1) observation in 2016 october
table2.dat 54 3574 Information of the new asteroids
table3.dat 57 129647 Light curve data set
table4.dat 72 122 The 122 reliable rotation periods
table5.dat 74 13 The 13 super-fast rotators
table6.dat 74 9 The nine super-fast-rotator candidates
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See also:
II/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers+, 2016)
J/A+A/508/1503 : Photometry of 3 main belt asteroids (Marciniak+, 2009)
J/A+A/529/A107 : Photometry of 4 main belt asteroids (Marciniak+, 2011)
J/A+A/545/A131 : Photometry of 8 main belt asteroids (Marciniak+, 2012)
J/ApJ/759/L8 : WISE/NEOWISE observations main belt asteroids (Masiero+, 2012)
J/ApJ/770/7 : WISE/NEOWISE Main Belt asteroids family member (Masiero+,2013)
J/A+A/561/A45 : Asteroid (341843) 2008 EV5 WISE light curves (Ali-Lagoa+,2014)
J/A+A/562/A48 : Light curves of asteroid (25143) Itokawa (Lowry+, 2014)
J/AJ/150/75 : Asteroid light curves from PTF survey (Waszczak+, 2015)
J/ApJ/814/65 : Jupiter HST light curves (Karalidi+, 2015)
J/ApJS/219/27 : Surveys of asteroid rotation periods using iPTF (Chang+, 2015)
J/A+A/596/A40 : Main-belt asteroids optical light curves (Szabo+, 2016)
J/AJ/152/54 : Spectroscopy main-belt Ch/Cgh-type asteroids (Vernazza+, 2016)
J/ApJ/818/176 : HST/WFC3 NIR photometry of 2M1207b (Zhou+, 2016)
J/ApJS/227/20 : Rotation periods of asteroids using iPTF (Chang+, 2016)
J/ApJS/234/37 : R-band K2 photometry of main-belt asteroids (Molnar+, 2018)
J/ApJS/237/19 : KMTNet LCs of ∼1000 main-belt asteroids (Erasmus+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 I1 --- Field [1/8] Observed field number
3- 7 F5.2 deg RAdeg [28/38] Degree of right ascension of the observed
field (J2000)
9- 13 F5.2 deg DEdeg [10/17] Degree of declination of the observed
field (J2000)
15- 17 F3.1 h Exp26 [6.3/6.8] Time duration of the 2016 Oct 26
observation (Δt)
19- 20 I2 --- N26 [23/24] Number of exposures for
the 2016 Oct 26 (Nexp)
22- 24 F3.1 h Exp27 [6.6] Time duration of the 2016 Oct 27
observation (Δt)
26- 27 I2 --- N27 [32] Number of exposures for the 2016 Oct 27 (Nexp)
29- 31 F3.1 h Exp28 [6.5] Time duration of the 2016 Oct 28
observation (Δt)
33- 34 I2 --- N28 [30/31] Number of exposures for
the 2016 Oct 28 (Nexp)
36- 38 F3.1 h Exp29 [5.7] Time duration of the 2016 Oct 29
observation (Δt)
40- 41 I2 --- N29 [25] Number of exposures for the 2016 Oct 29 (Nexp)
43- 45 F3.1 h Exp30 [6.9] Time duration of the 2016 Oct 30
observation (Δt)
47 I1 --- N30 [8] Number of exposures for the 2016 Oct 30 (Nexp)
49- 51 F3.1 h Exp31 [1.7] Time duration of the 2016 Oct 31
observation (Δt)
53 I1 --- N31 [7/8] Number of exposures for
the 2016 Oct 31 (Nexp)
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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- 6 I6 --- ID [110000/840809] Temporary identifier
8- 13 F6.2 au a [-99/23] Semi-major axis
15- 19 F5.2 au e_a [0/34] Uncertainty in a
21- 24 F4.2 --- e [0/0.94] Eccentricity
26- 29 F4.2 --- e_e [0/0.28] Uncertainty in e
31- 35 F5.2 deg i [0.11/100] Inclination
37- 41 F5.2 deg e_i [0/70] Uncertainty in i
43- 47 F5.2 mag wMAG [9/37] Absolute magnitude in wp1 band (Hw)
49- 54 F6.2 km Diam [0/106] Diameter
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- ID [110000/840809] Temporary identifier
8- 18 F11.5 d MJD [57687/57691] Modified Julian Date of
observation epoch, (JD-2400000.5)
20- 21 I2 h RAh [1/2] Hour of right ascension (J2000)
23- 24 I2 min RAm Minute of right ascension (J2000)
26- 31 F6.3 s RAs Second of right ascension (J2000)
33- 33 A1 --- DE- [+] Sign of declination (J2000)
34- 35 I2 deg DEd [8/17] Degree of declination (J2000)
37- 38 I2 arcmin DEm Arcminute of declination (J2000)
40- 44 F5.2 arcsec DEs Arcsecond of declination (J2000)
46- 50 F5.2 mag omag [13.62/22.5] Observed magnitude in Filter
52- 55 F4.2 mag e_omag [0.0/0.33] Uncertainty in omag
57- 57 A1 --- Filt Filter for omag (1)
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Note (1): Filters:
g (∼400-550nm; 1979 occurences), r (∼550-700nm; 3474 occurences),
i (∼690-820nm; 3193 occurences), z (∼820-920nm; 1764 occurences) and
w (combination of g, r, and i; 119237 occurences).
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- ID [110000/830672] Temporary identifier
8- 11 F4.2 au a [2.1/5.7] Semi-major axis
13- 16 F4.2 au e_a [0/0.62] Uncertainty in a
18- 21 F4.2 --- e [0.01/0.72] Eccentricity
23- 26 F4.2 --- e_e [0/0.2] Uncertainty in e
28- 32 F5.2 deg i [0.46/27] Inclination
34- 37 F4.2 deg e_i [0.01/6] Uncertainty in i
39- 43 F5.2 mag wMAG [17/21] Absolute magnitude in wp1 band (Hw)
45- 48 F4.2 km Diam [0.19/2.7] Diameter
50- 54 F5.2 h Per [0.51/32] Derived rotation period
56- 59 F4.2 h e_Per [0/1.8] Uncertainty in Per
61- 61 A1 --- f_Per [*] *: Half-period flag
63- 66 F4.2 mag Amp [0.26/1.4] Light curve amplitude (Δm)
68- 72 F5.2 mag wmag [21.1/22.3] Mean apparent magnitude in wp1 band
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Byte-by-byte Description of file: table[56].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- ID [220355/830672] Temporary identifier
8- 11 F4.2 au a [2.2/3.2] Semi-major axis
13- 16 F4.2 au e_a [0/0.4] Uncertainty in a
18- 21 F4.2 --- e [0.02/0.3] Eccentricity
23- 26 F4.2 --- e_e [0/0.2] Uncertainty in e
28- 32 F5.2 deg i [0.4/16] Inclination
34- 37 F4.2 deg e_i [0.01/6] Uncertainty in i
39- 43 F5.2 mag wMAG [17/21] Absolute magnitude in wp1 band (Hw)
45- 48 F4.2 km Diam [0.19/1.8] Diameter
50- 53 F4.2 h Per [0.5/1.7] Derived rotation period
55- 58 F4.2 h e_Per [0/0.01] Uncertainty in Per
60- 63 F4.2 mag Amp [0.2/0.8] Light curve amplitude (Δm)
65- 69 F5.2 mag wmag [21.2/22.3] Mean apparent magnitude in wp1 band
71- 74 I4 Pa c [3/3880] Estimated cohesion
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 05-Mar-2020