Photometry of asteroids taken in 2015 - Minor Planet Photometry

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Photometry of asteroids taken in 2015


Obs Code





Time (UT)



150d 20' 30"

-33d 42' 22"





151d 5' 45"

-33d 56' 51"





150d 20' 30"

-33d 42' 22"









SCT 0.25m

G11 Gemini v2





SCT 0.35m

Paramount MX





SCT 0.30m EQ8 f5/5 TCF ST10XME Q68

CDK 0.61m

MI-1250 Fork





Bracket next to Date Range indicate the location and system used. All period are light time corrected. An asterisk (*) after the name indicate published light curve in Minor Planet Bulletin.
Text colour correlate to the instrument system used for data aquisition.
PSABA: Photometric Survey of Asynchronous Binary Asteroids CALL: Collaborative Asteroid Light curve Link

176 Iduna

Test target using the 5" refractor with ST8300 (SBIG) camera for the first few sessions and ended with one session using 12" SCT with ST10XME (SBIG). The instruments proved to be quite good photometric instruments. Derived period is consistent with previous work

495 Eulalia

Requested observation by B. Warner and David Vokrouhlicky for shape modeling and H-G calculation.
starting date is 25/03/15 where the asteroid is rising in the early morning . Maybe a problem due to its proximity to the milky way galaxy.

07/05: very clear observing condition with 3 days post full moon . Low humidity and gentle breeze condition. images appear to be very well focused and contained. seeing was excellent. light curve looks clean with only very slight scatters.

908 Buda

David Vokrouhlicky requested observation of the asteroid for light curve analysis. Data pooled with Roger Groome
Data derived from Sep and Oct. sessions pointed to a period of 14.57h.  however so far December data is more towards 13.9h. more data will show definitive period.
973 Aralia
Preliminary light curve indicated a 10h period is quite likely. continue observation will clear up the uncertainty.
05/05: Full moon project. the first night data was deleted due to proximity to moon. only data on 0705 is useful and 06/05 is borderline.
07/05: light curve starting to take shape and period is narrowed down to 7.3h. data of 06/05 has a slight dip on the phase 0.25
1563 Noel
PSABA target on its 4th apparition

1264 Letaba
This target was selected from CALL advance selection website for favourable asteroid. The criteria was a relatively bright (instrumental mag of 14 ) to be observed around full moon. Both 14" and 12" scope from BMO was used to observe the asteroid . Initial observation of the first night 03/04 show a large amplitude of 0.30mag and the following 2 nights 03/05 and 03/06 showing a period of 3.238h +/- 0.008h with a smaller amplitude of 0.04mag.

Stephens observed in 2003 and found the period to be 32.16 + 0.03 h with amplitude 0.20 + 0.03mag. where as Behrend found in 2006 the period to be >12 with amplitude of a small 0.04mag.
After a month of observations, it was noted that during a long session of 8 hours, the light curve show a much longer primary period of >13h instead of the short 3.23h period noted earlier.

The final light curve period show 84.14h and magnitude of 0.16mag. the intial 3 nights showing attenuations were attributed to observation anomaly and were discarded.

1566 Icarus
NEO during its June 2015 close approach at instrument magnitude of 13.5mag.

1685 Toro

Request from David V. for a long term study of the YORP effect
) YORP effect in NEAs, enlarging the sample
(1685) Toro
Several apparitions by others in 1973-2008, 2012.
2010 05 08 to 12 - Observed (D. Higgins)
2013 04 07 to 08 - Observed (Prompt)
2015 07 01 to 06 - Observed (Leura)
2016 03 09 - 2n (D65); not needed actually, as it was observed by J. Oey in July 2015
2018 04 16 - 2n (Prompt or Leura)
2018 05 16 - 2n (Prompt or Leura)

future plan for its observations is shown above.
1829 Dawson

Binary suspect unconfirmed.
1829 Dawson

Dual period search. Primary period
1741 Giclas

Despite an extensive search was done together with Roger Groom from Perth West Australia for binary signature, the campaign failed to find repeating attenuation in the data. Changing in geometry was the most likely cause of failure. 
1829 Dawson

Dual period search. Attenuation shown.
2166 Handahl

PSABA target with no attenuation detected.
2015 CN13

A NEO observation that only 1 night was obtained during its close approach. This observation is in support of Brian Warner's observation in the attempt to confirm the commensurate rotational period close to that of the earth. It is either 24h or 12h. most likely 24h
2343 Siding Spring

An MBA of H=13.3 that mean a diameter of 6.85km.
A confirmed binary with a secondary light curve that may be caused by second satelite as reported in CBET 4206.  The Primary period is shown in the light curve.

2850 Mozhaiskij

A PSABA target . Period is 7.832h. The period is unique and target is closed. no other  associated problem arise with the observations.
2015 FS332
NEO asteroid post close approach (4th of october) observation. Absolute magnitude is 18.3 corresponding to about 660m diameter asteroid. It is an Apollo type asteroid and classified as Potentially Hazardous Asteroid or (PHA)
Radar doppler was done during close approach obtaining a strong signal. 
Rotation period is found to be consistent with that of Radar.
3435 Boury
4364 Shkodrov
4514 Vilen

Binary events recorded only. Porb is 16.05h (PRavec 2015)
4514) VILEN
D. Pray, Sugarloaf Mountain Observatory, South Deerfield, MA, U.S.A.;
P. Pravec, K. Hornoch, P. Kusnirak, J. Vrastil and H. Kucakova, Ondrejov
Observatory; V. Chiorny and V. Shevchenko, Kharkiv Observatory; V. Reddy,
Planetary Science Institute, Tucson; W. Cooney and J. Gross, Sonoita Research
Observatory, Sonoita, AZ, U.S.A.; and D. Terrell, Southwest Research
Institute, report that photometric observations obtained during Apr. 16-May 12
reveal that minor planet (4514) is a binary system with an orbital period of
16.85 � 0.01 hr. The primary shows a period of 2.89224 � 0.00009 hr, and
it has a lightcurve amplitude of 0.09 mag at solar phases 8-14 deg, suggesting
a nearly spheroidal shape. Mutual eclipse/occultation events that are 0.07-
to 0.14-magnitude deep indicate a lower limit on the secondary-to-primary
mean-diameter ratio of 0.26.
V. Reddy, D. Takir and J. A. Sanchez, Planetary Science Institute,
Tucson; and P. S. Hardersen, University of North Dakota, Grand Forks, report
that near-infrared spectroscopic observations (0.7-2.5 microns) of minor
planet (4514), obtained on 2015 Apr. 25 using the NASA Infrared Telescope
Facility on Mauna Kea, show that it is an X/M-type minor planet with a weak
pyroxene absorption band at 1 micron.

8474 Rettig

Synchronous binary discovery apparition announced in CBET 4122. Double peak noted

16126 1999 XQ86

PSABA  and asteroid pair target that maybe binary
16831 1997 WM21

PSABA target. This data was not very well linked . Unable to conclude if there is a secondary rotation period in the light curve. C14 focuser was not functioning and we have the support of the 12" ST10XME telescope.
2468 Repin

PSABA target. a continuous set of data was taken in an attempt to confirm if this target could have a secondary light curve
An asymetric light curve that was not binary but could be due to either shape or albedo effect. (Private communication Pravec)
The asymmatry is most pronounced in the 10/04 session.
Such asymmetry could be common among NEA in high solar phases where phase effects on irregular bodies are dominant.
However for MBAs observed in low to moderate solar phases such different level of lightcurve maxima are quite unusual.

3782 Celle

Data was taken with 0.61m CDK planewave f 5.8. reduction with CCDSoft  at bin 1x1. telescope control with SkyX. good condition we obtain a precision of 0.004m.

The light curve has changed somewhat during the month of May and a primary lightcurve is obtained showing a period of 3.7641h +/- 0.0002h.

3951 Zichichi

PSABA target of returned binary at the 3rd apparition. Observation is incomplete and cut short due to poor observing condition
3982 Kastel'

PSABA target showing the primary lightcurve with period of 8.495h.
The secondary period of 5.837h is known and appear as the deviation from the main curve shown here.
4541 Mizuno

Events only observed for binary discovery as reported in CBET 4097
9068 1993 OD

PSABA target taken with 24" scope. 
16698 1995 CX

PSABA target. Data was borderline due to poor observing condition however reduction was done using APASS catalog giving an accurate internal callibration of 0.02m. Found to be long period with shallow 0.3m amplitude. Insufficient data to show if tumbling exist
16955 1998 KU48

PSABA target. Data was reduced with APASS catalog. Starting measurement was done from the image taken during transit. Catalog stars SD was 0.008m. No deviation noted

30776 1987 QY

Target of opportunity in the same fov as 2691 Sersic taken on 14th September 2015. Only a one night observing session done. Period shown is indicative only.
17584 1994 XF1

PSABA target. Initial 2 sessions were taken with short exposures. target is relatively faint at instrumental magnitude of 17th. Will increase exposure to 180s
This asteroid is found to be a tumbler with 2 period Fourier series as described at 
The observing campaign is now closed.
44091 1998 FB106

49953 1999 XL215

PSABA target. probable binary however after numerous sessions , not attenuation detected apart from the sesson 07/28. However this possible event could be due to bright moon light effecting the light curve

77357 2001 FW125
A very faint object happened to be in the same field as 6158 Shosanbetsu. The average 18.8 red Magnitude is the limit for good photometry for the 24".

141527 2002 FG7

Data observed and grouped to show the change in different phase angle. The object as it travel through the close fly-by, will change its phase angle.

163696 2003 EB50

An Apollo NEA closest approach in early december 2015.
A long period asteroid of 62.3h high probability of being a tumbler. Radar has confirmed a long rotational period consistent with the period we found. Previous work by Warner (2014) found the period to be 27h.
19289 1996 HY12

PSABA target. This is a paired asteroid with emphasis on searching for a binary component.
41588 2000 SC46

PSABA target. Multiple coverage with no deviations noted.
70799 1999 VY55

Target of opportunity in the same field as 2468 Repin. Unfortunately only 1 night was possible 10/06. Limiting magnitude of 18m Rs filter.

141527 2002 FG7
the whole 8 sessions of 03/19 show that the asteroid is tumbing. with its large 1mag amplitude, tumbling asteroid is quite common. Sessions are compared with APASS catalog stars reducing errors to 0.02m average without filters. the first session the focusing was off but the rest of the night, it was focus accurately.
the whole of the 03/18 sessions have very poor focus.

357439 2004 BL86

The close apporoach of this NEO has given the astronomical community the opportunity to observe this asteroid and discover the presence of a satelite.  It was also confirmed by RADAR observations 

The binary nature was revealed and the result reported in CBAT

141527 2002 FG7

Data was taken with 5", 14" ,24" and 12"

348400 2005 JF21 (Aug 01-15)

1st half of August the asteroid is travelling rapidly as observed from earth (14.68'/min) requiring different comparison stars and different sessions each night when it reached the closest distance from earth in mid August 15th.
The latest version of Canopus V could correctly linked individual session even when the object is approaching rapidly.
Period = 2.4146h +/- 0.0004h
Amplitude= 0.10mag
PA =36.1 - 45.6
LPAB=288.6 - 303.5
BPAB= 8.6 - (-17.4)
348400 2005 JF21 (July 2015)

The observations during the month of July show very low amplitude of 0.05m with 2 sessions showing attenuation. 
Period : 2.4299h +/- 0.0005h
Amplitude: 0.05mag
PA=31.4- 35.9
BPAB= 15.4-9.4
348400 2005 JF21 (September 2015)

Period= 2.4150h +/- 0.0002h
Amplitude= 0.13mag
PA = 74.2- 59.2
LPAB= 352.4, 0,  29.7
BPAB= (-40.2) - (-34)
348400 2005 JF21 (16/08-31/08)

This is a RADAR NEO target. This target is detected during its close approach showing 1 moon and possible 2 . Due to its fast movement, this target is not easily linked and we have been unable to confirm the binary or ternary nature of it. More observations will be carried out in later months. Currently the 14' scope was used but some success has been shown with 5" refractor during the close approach.

Period = 2.4142 h +/- 0.0004h
Amplitude = 0.14mag
PA = 48.0 - 73.9
LAPB= 305.7 - 350.1
BPAB=(-20.3) - (-40.2)
348400 2005 JF21 (1/11-30/11)

Period 2.4152h +/- 0.0003h
Amplitude: 0.10mag
PA : 33.0 - 22.2
LPAB : 46 - 54.3
BPAB: (-26.6) - (-19.5)
413577 2005 UL5

348400 2005 JF21 (1/10 -31/10)

Period: 2.4145h +/- 0.0001h
Amplitude: 0.14mag
PA: 58.4- 33.7
LPAB: 30.5 - 45.7 
BPAB: (-33.8) - ( -26.9)
(436724) 2011 UW158

This is found to be a super fast rotater asteroid. Rotation rate is 0.61072h. Radar observation show this to be an elongated object.
Observations from BMO show an amplitude of 0.76 mag but Bruce Gary found the shape to have 3.5:1 ratio after taken into account opposition effect and phase changes. the maximum amplitude during the close approach changed to >2 mag.
Most asteroids with rubble pile model will disintegrate at such high rotation period but this asteroid was a monolithic object that from the spectrometric observations consist of solid structure with high percentage of platinum.
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