This document summarizes research determining the orbit of the potentially hazardous asteroid 2102 Tantalus. Four sets of images of the asteroid were taken using ground-based telescopes. The images were analyzed to determine the asteroid's position over time. Its right ascension and declination were calculated using a least squares plate reduction program. Photometry of the images found apparent magnitudes ranging from 16.0 to 17.5. The orbital elements of the asteroid, including eccentricity, semimajor axis, and inclination, were computed using the method of Gauss. The research provides an improved model of 2102 Tantalus' long-term trajectory.

1. 1
Determining the Orbit of Near-Earth Asteroid
2102 Tantalus
Congwen (Nancy) Xu, Westmont SSP 2014, Nehal Rawat, Westmont SSP 2014, and Anthony Flores, Westmont SSP
2014
Abstract—Discovered in 1975, 2102 Tantalus is a Potentially
Hazardous Asteroid (PHA) with an eccentric orbit affected by the
gravitational fields of nearby planets and the Sun. Using four sets
of CCD images taken near solar opposition from ground-based
telescopes, the orbital elements and trajectory of 2102 Tantalus
were determined. The FITS files were analyzed to centroid the
asteroid, and the right ascension (RA) and declination (Dec)
of the asteroid at each observation were determined through
a Least Squares Plate Reduction (LSPR) program. Photometry
performed on the images reveals apparent magnitudes on the
order of 16.0-17.5, and the orbital elements of the asteroid
were computed. Statistical uncertainty was accounted for by
fitting jackknifed data from seven observations to a Gaussian
distribution. The research indicates an eccentricity of 0.301, a
semimajor axis of 1.438 AU, an inclination of 63.602◦
, longitude
of the ascending node of 94.477◦
, an argument of perihelion of
61.425◦
, and a time of last perihelion of JD 2456738.18.
Keywords—2102 Tantalus, NEO, Orbital Elements, PHA
I. INTRODUCTION
Potentially Hazardous Asteroids (PHA) are celestial objects
with a minimum orbit intersection distance of 0.05AU and a
maximum absolute magnitude of 22.0 [1]. They are hazardous
to inner solar system planets due to their eccentric orbits. PHAs
such as 2102 Tantalus (1975 YA) have the potential to collide
with the Earth as a result of gravitational perturbations from
nearby planets and stars. At the time of discovery in December
1975, 2102 Tantalus approached the Earth at a distance of
0.047AU [4]. The most recent close approach was observed
on June 28, 2014 as seen in Figure 1. Measuring the orbits
of such asteroids is necessary for refining previous models
of the asteroid’s orbit to determine the time, trajectory, and
probability of an Earth collision.
Fig. 1. Most Recent Close Approach of 2102 Tantalus on June 28, 2014 [5]
This paper studies the orbital dynamics of 2102 Tantalus
through local observations from the 14-inch Meade and 0.6-m
Keck telescopes in Santa Barbara, California. Remote obser-
vations were also taken from the Prompt 1, Prompt 2, and
Prompt 8 telescopes at the Cerro Tololo Observatory in La
Serena, Chile. The CCD images were processed to centroid
the asteroid in each of the FITS file arrays, and a Least
Squares Plate Reduction (LSPR) program determined the right
ascension (RA) and declination (Dec) of 2102 Tantalus while
accounting for statistical uncertainty. The orbital elements of
the asteroid were computed with the Method of Gauss through
multiple computational iterations. Our results advance the
current understanding of 2102 Tantalus’ long-term trajectory
as well as provide an improved model of its orbit.
II. METHODS FOR DATA COLLECTION AND ANALYSIS
A. Observation Specifications
Th CCD images were taken from two observatories with five
different telescopes. The specifications of each observatory are
shown in Table I.
TABLE I. OBSERVATORY AND TELESCOPE SPECIFICATIONS
Observatory Location Latitude
Longitude
Telescope Field of View
Westmont
College
G60 N 34 26’ 59.24”
W 119 39’ 33.59”
0.6m Keck 17’ x 17’
Westmont
College
G60 N 34 26’ 59.24”
W 119 39’ 33.59”
14in Meade 20’ x 16’
Cerro Tololo
Observatory
807 S 30 10’ 03.50”
W 70 48’ 19.40”
Prompt 1 10’ x 10’
Cerro Tololo
Observatory
807 S 30 10’ 03.50”
W 70 48’ 19.40”
Prompt 2 21’ x 16’
Cerro Tololo
Observatory
807 S 30 10’ 03.50”
W 70 48’ 19.40”
Prompt 8 22.6’ x 22.6’
The STL-1001E Charge-coupled Device (CCD) used at the
main 0.6m Keck telescope in Westmont College has a 1024 x
1024 pixel array (24.6 mm x 24.6 mm). The device was used
with a pixel scale of 1 arcsecond/pixel. The STL-1301E CCD
used at the 14” Meade telescope at the Westmont Campus
has a 1280 x 1024 pixel array (20.5mm x 16.4 mm) that
encompasses 1.3 million pixels 16 x 16 microns in size [3].
Both types of CCD cameras allow for 1x1, 2x2, and 3x3

2. 2
binning, which were experimented with throughout different
observation sessions for the best quality images.
Three telescopes in Chile were also available for use through
the Cerro Tololo Observatory(CTIO). Proposals were sent to
the Prompt 1, Prompt 2, and Prompt 8 telescopes for remote
image collection. Of the three telescopes, Prompt 8 has the
largest pixel scale at 0.663 arcseconds/pixel compared to the
0.59 arcsecond/pixel scale of both Prompt 1 and Prompt 2 [6].
Default binning is 1x1 binning. All three of these telescopes
have a diameter of 16” [7].
B. Observation Preparation
For each observation, the approximate Right Ascen-
sion (RA), Declination (Dec), and Apparent Magnitude of
the asteroid were found through the JPL Horizons web-
site(http://ssd.jpl.nasa.gov/horizons.cgi) from the beginning
time of observation to the end time with 10 minute intervals.
The Hour Angle (HA) at the beginning of observation was
calculated using the Local Sidereal Time (LST) and Right
Ascension.
HA = LST − RA (1)
Star Finder Charts were also included according to the
telescopes’ field of view to help locate the asteroid relative
to nearby stars used as references. These charts were found
from the USNO Database [2].
C. Asteroid Location
Using the Hour Angle and Declination estimates, the rough
position of the asteroid in the sky was determined. A bright star
within 30◦
of the asteroid’s position was located in order to do a
pointing calibration of the telescope. The telescope was slewed
to the reference star and the star was centered in the telescope’s
field of view. Images were taken and focused using CCDSoft’s
focusing tools. After the telescope pointing calibration was
set, the telescope was moved to the target asteroid’s field of
view. A subframe of the field of view was selected, continuous
images were taken with a 2-5 second exposure time, and the
focus was adjusted using the DFM control paddle. Fine focus
was achieved when the stars in the subframe were as small
and radially symmetric as possible. The subframe option was
then dechecked to view the entire image selection, which was
matched with the star patterns on the Sky6 chart and compared
to the star finder charts to determine the exact location of the
asteroid.
D. CCD Images
A total of four independent measurable observations were
made from June 15, 2014 to July 30, 2014. For each obser-
vation, multiple sets of images were taken, with at least 3
sets of 5 images each. There was a 5-10 minute time span
between successive image sets, which was used to identify the
location of the asteroid in the imageby tracking the asteroid’s
movement. Five images were taken in rapid succession in
each set to ensure that temporary disturbances such as cosmic
rays could be eliminated through median combination of the
images. Only one of the three sets from each observation was
used in the final measurements to determine RA and Dec.
The exposure time and binning of the image sets varied
based on the magnitude and rate of the asteroid at the time
of observation. Small exposure time reduced the likelihood
of streaking in the images but also led to fainter images.
Likewise, a large binning (3x3) prevented streaking but also
greatly increased the uncertainty of the measurements. The
exposure time and binning of the images are shown in Table
II.
TABLE II. EXPOSURE TIME AND BINNING FOR OBSERVATIONS
Observation Exposure Time Binning
Keck1 30.0 seconds 2 x 2
Keck2 10.0 seconds 1 x 1
Keck3 30.0 seconds 2 x 2
Chile1 20.0 seconds 1 x 1
III. DATA ANALYSIS
A. Centroid
After the images were taken, they were edited and analyzed
in MaxIm DL imaging software. Once the asteroid was located,
its brightest pixel was taken for centroid calculation. A centroid
program took this brightest pixel and constructed a square
aperture of count values around it. From the aperture, a
weighted average of all the counts was taken to determine
the center of the object in question based on the brightness of
the surrounding pixels.
B. Least Squares Plate Reduction
In order to calculate the RA and Dec of the asteroid, its
centroid in the CCD images was compared to 8 surrounding
reference stars in the same field of view. Using TheSkyX
software, each reference star was located in the UCAC3
database and the known right ascension and declination was
recorded. Afterwards, the centroid of each reference star was
taken from the original image in order to calculate the plate
coefficients needed to solve for the RA and Dec of a particular
object in the same image, given by the formulas:
α = b1 + a11X + a12Y (2)
δ = b2 + a21X + a22Y (3)
where
Σαi
Σαi ∗ xi
Σαi ∗ yi
=


N Σxi Σyi
Σxi Σx2
i Σxi ∗ yi
Σyi Σxi ∗ yi Σy2
i

 ∗
b1
a11
b12
(4)
and

3. 3
Σδi
Σδi ∗ xi
Σδi ∗ yi
=


N Σxi Σyi
Σxi Σx2
i Σxi ∗ yi
Σyi Σxi ∗ yi Σy2
i

 ∗
b2
a21
b22
(5)
When the x and y coordinates of the asteroid’s centroid
were entered into the transformation equation, its RA and dec
were returned, as well as the residuals in the RA and Dec of
each individual star and the uncertainty of the overall plate
coefficients.
C. Method of Gauss
In this research, the Method of Gauss was used to determine
the orbit of the asteroid. First the position and velocity of the
asteroid in Ecliptic coordinates were calculated.
To determine the position vector of the asteroid, the fun-
damental vector triangle for objects orbiting the Sun is used
(Fig2):
Fig. 2. Vector Triangle
where
ρˆρ = r + R (6)
Once the Right Ascension and Declination of the asteroid
at each observation time (i= 1, 2, 3) were calculated, the value
of ˆρi was determined through Equation 7.
ˆρi =
cosαicosδi
sinαicosδi
sinδi
(7)
The position of the asteroid can be determined at any time
using the f and g series, where time is in modified time
(Equation 8):
r(τ) = fr2 + g˙r2 (8)
Once the position vector is determined, the velocity vector
can also be calculated using Equation 9:
˙r2 =
f3
(g1f3 − g3f1)
r1 −
f1
(g1f3 − g3f1
r3 (9)
Using several iterations of the Method of Gauss until ρ2
converged, more accurate values of the position vector and the
velocity vector were calculated, resulting in the vector orbital
elements for the time of the second observation. These results
are in equatorial coordinates 1
and need to be converted to
ecliptic coordinates before the classical orbital elements can
be calculated.
D. Classical Orbital Element Calculations
The classical orbital elements used to determine the orbit
of the asteroid are as follows:
a - Semimajor axis
e - Eccentricity of the orbit
i - Inclination
Ω - Longitude of the ascending node
ω- Argument of the perihelion
T - Time of perihelion passage
The values of the orbital elements were calculated based
on Kepler’s Equations, gravitational motion, and classical
Newtonian mechanics. The semimajor axis was calculated
using the vis-viva equation (Eq 10):
1
a
=
2
r
−
v2
µ
(10)
The eccentricity was calculated as the magnitude of the eccen-
tricity vector (Eq 11):
e = (
r0xh
µ
−
r0
|r0|
) (11)
The inclination was calculated as(Eq 12):
cosi =
h · ˆz
h
(12)
where h is given by (Eq 13):
h = r0 × ˙r0 (13)
The longitude of the ascending node was given by (Eq 14):
cosΩ =
Nx
|N|
(14)
where N is given by Eq. 15
N = ˆz × h (15)
The argument of the perihelion can be computed as (Eq 16):
cosω =
Nx
|N|
(16)
The time of perihelion passage was computed using the
mean anomaly (M) and the eccentric anomaly (E) through
Euler’s method.
1Equatorial coordinates are 3-dimensional Cartesian coordinates where the
xy plane is an extension of the equatorial plane of the earth and the z-axis is
an extension of the North pole. The x-axis points in the direction of the suns
location on the celestial sphere at vernal equinox.

4. 4
E. Statistical Analysis
In order to calculate the true values and uncertainty of
the data, the data from the observations were used in the
jackknife method along with three sets of observations from
another team to find the mean value and standard deviation
of the classical orbital elements. The seven observations used
for the jackknife method are shown in Table III. The orbital
elements were computed for each possible subgroup of three
observations. The resulting values were then fit to a Gaussian
distribution. The mean and standard deviation were computed
for each value from the 35 observation combinations. Seven
observations were used to provide a larger sample set for better
measurement uncertainty and precision.
TABLE III. SEVEN OBSERVATIONS USED FOR THE JACKKNIFE
METHOD AND COMPUTING THE CLASSICAL ORBITAL ELEMENTS
Observation JD Time RA
(decimal
hours)
Dec
(decimal
degrees)
Latitude
(decimal
degrees)
Longitude
(decimal
degrees)
1 2456834.80 16.096 37.381 34.448 -119.663
2 2456850.78 15.308 1.778 34.448 -119.663
3 2456861.71 15.124 -14.501 34.448 -119.663
4 2456863.54 15.110 -16.570 -30.168 -70.805
5 2456841.85 15.642 20.679 34.448 -119.663
6 2456855.72 15.201 6.482 34.448 -119.663
7 2456859.72 15.144 -12.055 34.448 -119.663
F. Photometry
The images for each observation were used to calculate the
apparent magnitude of the asteroid. For each image, TheSkyX
software was used to determine the apparent magnitude of a
reference star within the field of view of the asteroid. The
software used the selected star as a calibration point for
determining apparent magnitude of the asteroid. This was
performed by summing the counts within the aperture of the
star. An annulus around the star was used to determine the
background count, which was then subtracted from the sum
of the star and background count to give the star count.
IV. RESULTS
A. Images
Four groups of measurable CCD images were obtained
through the individual observations. Each group of CCD
images was composed of at least 3 sets with at least 5
images per set. The image set used for processing was chosen
based on the number of available reference stars near the
asteroid. Other considerations included the image set quality
and the presence of potentially disturbing nearby objects.
When possible, the median combined image of a given set was
used for measurements, although single images from sets were
used when streaking was present in the median combined ones.
This phenomenon occurred for long exposure times, which was
generally avoided. Table IV categorizes the images that were
used from each set for measurement.
TABLE IV. IMAGES USED FOR MEASUREMENT
Observation Time Set # Image #
Keck1 2014-06-26 07:12:56.962 UT 3 5
Keck2 2014-07-12 06:44:15.00 UT 2 Median Combined
Keck3 2014-07-23 05:14:43.16 UT 2 Median Combined
Chile1 2014-07-25 01:01:55 UT 5 Median Combined
The corresponding inverted CD images are displayed in
Figures 1-4.
Fig. 3. Keck 1 Image

5. 5
Fig. 4. Keck 2 Image
Fig. 5. Keck 3 Image
Fig. 6. Chile 1 Image
B. Image Processing
After determining the centroid of the asteroid in each of
the four image sets, a Least Squares Plate Reduction was
performed on the asteroid and eight surrounding stars. By
minimizing the value of the chi-squared sum of a linear
regression, the RA and Dec of the asteroid was determined.
All images used had an RA and Dec residual on the order of
less than or equal to 10−4
degrees for the asteroid. This cutoff
was used to ensure the precision of the measurements 2
. The
results are shown in Table V.
TABLE V. CENTROID AND LSPR RESULTS
Observation Centroid pixel RA Dec
Keck 1 (326.01, 396.99) 16h 05m 43.62s +37◦
22’ 51.23”
Keck 2 (550.99, 776.00) 15h 18m 30.09s +01◦
46’ 41.08”
Keck 3 (289.01, 227.00) 15h 07m 25.43s -14◦
30’ 04.32”
Chile 1 (494.91, 148.26) 15h 06m 34.50s -16◦
34’ 13.50”
C. Classical Orbital Elements
The classical orbital elements were computed based on the
RA and Dec of the asteroid in seven observations. The final
computed orbital elements are the mean value of the orbital
elements from 35 jackknifed sets of three observations each.
Table VI displays computed orbital elements.
2See appendices for LSPR residuals

6. 6
TABLE VI. 2102 TANTALUS ORBITAL ELEMENTS
Orbital
Element
Mean Value Standard Deviation
a 1.438 0.342
e 0.301 0.007
i 63.602 2.665
Ω 94.477 1.051
ω 61.425 14.615
T 2456738.18 8.570
TABLE VII. 2102 TANTALUS ORBITAL ELEMENTS COMPARED TO
JPL VALUES
Orbital
Element
Mean Value Standard De-
viation
JPL Values JPL
Uncertainty
a 1.4379 0.3417 1.2900 1.04E-09 AU
e 0.3014 0.0067 0.2991 6.24E-08
i 63.6018 2.6647 64.0077 1.69E-05◦
Ω 94.4769 1.0509 94.3731 6.94E-06◦
ω 61.4251 14.6153 61.5443 1.79E-05◦
T 2456738.176 8.5701 2456737.7682 2.20E-05 JED
D. Photometry
TABLE VIII. PHOTOMETRY (APPARENT MAGNITUDE
MEASUREMENTS)
Observation Reference Star Apparent
Magni-
tude of
Star
Apparent
Magni-
tude of
Asteroid
Keck 1 UCAC3 255:114437 16.22 16.68
Keck 2 UCAC3 184:122929 16.03 16.84
Keck 3 UCAC3 152:152928 14.83 17.58
Chile 1 UCAC3 147:146961 15.59 17.86
E. Ephemeris Generation Check
Unfortunately, the ephemeris generation using calculated
orbital elements produced similar RA values to those expected
but the generated declination was extremely different from
what was originally observed.
TABLE IX. EPHEMERIS GENERATION CHECK COMPARISON:
OBSERVED VS. PREDICTED VALUES
Time
(JD)
RA Observed Dec
Observed
RA Calculated Dec
Calculated
2456861.72 15h 07m 25.43s -14 30’ 4.32 15h 10m 47.4s 2◦
58’ 6.1”
V. DISCUSSION
In order to calculate the classical orbital elements of 2102
Tantalus, sets of images were taken from 4 observations
spanning from June 15, 2014 to July 30, 2014. Unfortunately,
due to inclement weather in the middle of this time period,
most images were recorded either at the very beginning of
the period or the very end. As a result of this, some of the
observations used in the jackknife method for determining the
classical orbital elements were close in time. This resulted in
values that greatly differed from those predicted by JPL. On the
other hand, data from observations that occurred on opposite
ends of the time period resulted in values of classical elements
that were closer to JPL predictions. The effect of this variation
was mitigated as the sample size of the data increased, allowing
the data to be fit to a Gaussian model more accurately.
Moreover, when using the jackknife method on observations
taken only a few Julian days apart, the orbital determination
program failed to converge on a plausible value. Therefore,
while the jackknife method should have resulted in 35 data
points, only 34 could be used because the incorrect conver-
gence resulted in a data value. This was not a statistical outlier.
Additionally, due to Tantalus’s speed, not all data were taken
from combined image sets. For example, when a thirty second
exposure time in the Keck1 set caused 2102 Tantalus to streak,
a single image instead of a median combined image had to
be taken for analysis. While this increased the possibility of
a cosmic ray saturating the image, extreme care was taken to
choose an image from the third set where Tantalus was a single
distinguishable point and no cosmic rays or other polluting
sources were present.
VI. CONCLUSION
According to the calculated orbital elements, 2102 Tantalus
has a semi-major axis(a) of 1.438AU with a standard deviation
of 0.342AU, an eccentricity of orbit of 0.301 with a standard
deviation of 0.007, an angle of inclination of 63.602◦
with a
standard deviation of 2.665◦
, a longitude of the ascending node
of 94.477◦
with a standard deviation of 1.051◦
, an argument
of perihelion of 61.425◦
with a standard deviation of 14.615◦
,
and a time of last perihelion of JD 2456738.18 with a standard
deviation of 8.57 Julian days.
Although the values are not entirely consistent with the JPL
Orbital Elements, the observations lend greater understanding
to the trajectory and orbit of 2102 Tantalus. The uncertainties
are larger than ideal despite small LSPR residuals. Possible
error could have derived come from inaccurate convergence
of the OD program for observations that were too close in
Julian date. However, the effect of this phenomenon was
minimized by the jackknife method. Some selected reference

7. 7
stars radially spread around the asteroid were not used because
they were unavailable in TheSkyX database. In this case,
alternate reference stars were selected instead.
Compared to the JPL ephemerides, the RA and Dec of
the asteroid as determined by the calculated classical orbital
elements were similar to the values in the database. The
calculated declination deviated from the JPL value more than
the RA. This is most likely due to the inconsistency between
JPL and the calculated values for the semimajor axis. The
other orbital elements were extremely close in value to the JPL
values and corroborate the database’s predictions (see Table
VII).
Furthermore, alternate methods to determine the orbit of the
asteroid such as the Method of Laplace or using the Method
of Gauss with higher orders of the f and g series can improve
calculated results.
APPENDIX A
LSPR RESIDUALS
TABLE X. KECK 1 RESIDUALS
Target Ob-
ject
RA Dec σRA σDec
Asteroid 16h 05m 43.62s +37◦
22’ 51.23” 0.04337s 0.2623”
Ref 1
UCAC3
255:114500
16h 06m 18.27s +37◦
20’ 29.09” -0.01512s 0.1439”
Ref 2
UCAC3
255:114450
16h 05m 37.45s +37◦
21’ 31.01” -0.0070s -0.0408”
Ref 3
UCAC3
255:114483
16h 05m 59.14s +37◦
23’ 05.86” 0.0575s -0.1692”
Ref 4
UCAC3
255:114466
16h 05m 46.87s +37◦
25’ 18.21” -0.0291s 0.1186”
Ref 5
UCAC3
255:114440
16h 05m 24.48s +37◦
26’ 32.72” -0.0416s -0.3219”
Ref 6
UCAC3
255:114430
16h 05m 18.14s +37◦
26’ 23.70” 0.0331s 0.2733”
Ref 7
UCAC3
255:114482
16h 05m 58.50s +37◦
27’ 06.92” 0.0339s 0.2225”
Ref 8
UCAC3
255:114490
16h 06m 07.83s +37◦
25’ 52.77” -0.0316s -0.2264”
TABLE XI. KECK 2 RESIDUALS
Target Ob-
ject
RA Dec σRA σDec
Asteroid 15h 18m 30.09s +01◦
46’ 41.08” 0.0191s 0.6042”
Ref 1
UCAC3
184:122914
15h 18m 31.29s +01◦
46’ 11.14” 0.0119s -0.2053”
Ref 2
UCAC3
184:122873
15h 18m 17.18s +01◦
47’ 55.93” 0.0237s -0.0119”
Ref 3
UCAC3
184:122867
15h 18m 15.56s +01◦
48’ 06.53” 0.0178s -0.1383”
Ref 4
UCAC3
184:122840
15h 18m 06.39s +01◦
48’ 25.71” -0.0070s 0.0549”
Ref 5
UCAC3
184:122843
15h 18m 07.38s +01◦
47’ 25.47” -0.0156s -0.2366”
Ref 6
UCAC3
184:122856
15h 18m 11.39s +01◦
42’ 42.74” -0.0066s 0.9933”
Ref 7
UCAC3
184:122870
15h 18m 16.48s +01◦
42’ 34.14” -0.0027s -0.7823”
Ref 8
UCAC3
184:122935
15h 18m 36.00s +01◦
49’ 35.02” -0.0216s 0.3261”
TABLE XII. KECK 3 RESIDUALS
Target Ob-
ject
RA Dec σRA (hr) σDec
(deg)
Asteroid 15h 07m 25.43s -14◦
30’ 4.32” 1.1764e-05 0.0001307
Ref 1
UCAC3
152:152928
15h 07m 20.54s -14◦
29’ 45.57” -1.2437e-05 -0.0001390
Ref 2
UCAC3
152:152909
15h 07m 11.94s -14◦
29’ 55.60” 4.1622e-06 -5.1605e-05
Ref 3
UCAC3
152:152901
15h 07m 06.13s -14◦
28’ 05.67” -1.2466e-05 0.0002100
Ref 4
UCAC3
152:152899
15h 07m 05.15s -14◦
26’ 47.97” 1.2684e-05 -8.8184e-05
Ref 5
UCAC3
151:157820
15h 07m 14.71s -14◦
32’ 41.02” -1.1402e-06 -4.4892e-05
Ref 6
UCAC3
151:157841
15h 07m 27.86s -14◦
32’ 49.98” 1.2299e-05 9.1443e-05
Ref 7
UCAC3
151:157854
15h 07m 34.53s -14◦
31’ 42.27” -6.3594e-06 -4.4953e-06
Ref 8
UCAC3
152:152962
15h 07m 34.70s -14◦
27’ 56.05” 3.2587e-06 2.5931e-05

8. 8
TABLE XIII. CHILE 1 RESIDUALS
Target Ob-
ject
RA Dec σRA (hr) σDec
(deg)
Asteroid 15h 06m 34.50s -16◦
34’ 13.50” 5.0264e-06 5.5884e-05
Ref 1
UCAC3
147:146952
15h 06m 33.53s -16◦
33’ 46.64” 9.162e-06 0.00011
Ref 2
UCAC3
147:146945
15h 06m 28.96s -16◦
33’ 36.66” -6.0785e-07 -3.987e-05
Ref 3
UCAC3
147:146940
15h 06m 26.84s -16◦
32’ 30.73” 1.9408e-07 -1.237e-05
Ref 4
UCAC3
147:146950
15h 06m 31.97s -16◦
35’ 12.74” -1.1353e-07 -1.7407e-05
Ref 5
UCAC3
147:146933
15h 06m 23.12s -16◦
35’ 18.45” -4.0644e-06 -7.1762e-06
Ref 6
UCAC3
147:146970
15h 06m 41.92s -16◦
33’ 59.17” 9.5395e-07 -1.7507e-05
Ref 7
UCAC3
147:146978
15h 06m 45.44s -16◦
33’ 00.09” -4.9148e-06 -1.8593e-05
Ref 8
UCAC3
148:145844
15h 06m 22.02s -16◦
29’ 46.13” -6.0978e-07 -4.9114e-07
ACKNOWLEDGMENT
Thank you to the SSP faculty and staff for providing the
instruction, resources, and support necessary for completing
this research report. Special thanks to Dr. Michael Faison, Dr.
Cassandra Fallscheer, Ms. Martinez and TAs Andrew, Daksha,
Christine, and James.
REFERENCES
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and Catalogue Data. Web. 26 July 2014. http://www.nofs.navy.mil/tmp/
fch6ScjEQ fch.html
[3] Santa Barbara Instrument Group, Model STL-1301e Typical Specifica-
tions, STL-1001E Operating Manual. Web. 26 July 2014.
[4] Jet Propulsion Laboratory, 2102 Tantalus (1975 YA), JPL Small-Body
Database Browser. Web. 26 July 2014. http://ssd.jpl.nasa.gov/sbdb.cgi?
sstr=2102+Tantalus
[5] Jet Propulsion Laboratory, Orbit Diagram: 2102 Tantalus (1975 YA),
JPL Small-Body Database Browser. Web. 26 July 2014.
[6] SKYNET, Our Telescopes, SKYNET: Our Scopes. Web. 26 July 2014.
http://skynet.unc.edu/index.php?selection=telescopes
[7] University of North Carolina, Introduction to SKYNET, Prompt
Telescopes. Web. 26 July 2014. http://user.physics.unc.edu/∼reichart/
ASTR101L-1.pdf