Manual review to select a reliable rotation period of small solar system bodies (SSSBs) is a very time-consuming process. With the growing volume of lightcurve data collected by wide-field, high-cadence surveys, such manual inspection has become impractical and unsustainable. In response to this challenge, we present a new algorithm, called the significance-convergence test, which provides a quantitative way to select reliable rotation periods of SSSBs obtained from these wide-field, high-cadence surveys. This algorithm was developed based on two simulations, each containing 162,000 synthetic lightcurves generated according to the observational conditions and data properties of the surveys from the phase I of the Formation of the Outer Solar System: an Icy Legacy (FOSSIL I) and Pan-STARRS 1 (PS1). Using two parameters extracted from period analysis, the successful recoveries of the input rotation periods from the synthetic lightcurves can be distinguished from unsuccessful recoveries and noisy lightcurves. The first parameter, 1/S, indicates the significance of the best-fit spin rate, while the second parameter, C, represents the condition of convergence of the best-fit lightcurve. This algorithm can also be used as a mapping to the conventional quality code of manual review, U, defined by Warner et al. The significance-convergence test thus provides a practical alternative to manual review, which is a time-consuming and biased process.

Trans-Neptunian objects (TNOs) with large perihelion distances (q > 60 au) and semi-major axes (a > 200 au) provide insights into the early evolution of the Solar System and the existence of a hypothetical distant planet. These objects are challenging to observe, and thus their detections are still rare, yet they play a crucial role in constraining models of Solar System formation. Here we report the discovery of a Sedna-like TNO, 2023 KQ(14), nicknamed 'Ammonite', with q = 66 au, a = 252 au and inclination i = 11 degrees. The orbit of Ammonite does not align with those of the other Sedna-like objects and fills the previously unexplained 'q-gap' in the observed distribution of distant Solar System objects. Simulations demonstrate that Ammonite is dynamically stable over 4.5 Gyr. Our analysis suggests that Ammonite and the other Sedna-like objects may have shared a primordial orbital clustering around 4.2 Ga. Furthermore, the stable orbit of Ammonite favours larger orbits (similar to 500 au) rather than closer ones for a large hypothetical planet in present-day trans-Neptunian space.

Within the outer Solar System exists the Kuiper belt. This Kuiper belt is made up of many icy planetesimals, the remaining relics of planet-forming bodies that failed to evolve into a planet beyond Neptune. The smaller members of the Kuiper belt (with r mag > 22) generally show linear and featureless spectra. Additionally, due to the dimness of these objects observing their spectra can be particularly difficult. Therefore, broadband photometry is often used to characterise their surfaces. The broadband photometry can be used as a proxy for composition, as it provides enough information to characterise the optical and near-infrared spectral slopes ofthese Kuiper Belt Object (KBO) surfaces.The Colours of the Outer Solar System Origins Survey (Col-OSSOS, Schwamb et al., 2019) took near-simultaneous g-, r- and J-band broadband photometry of a sample of KBOs with unprecedented precision using the Gemini North telescope. As with previous colour surveys (e.g. Tegler et al., 2016), they showed abimodal colour distribution in optical / near-infrared colours for the dynamically ‘hot’ population. We split this colour distribution into the ‘neutral’ coloured population with (g−r) < 0.75 and the ‘red’ coloured populationwith (g−r) ≥ 0.75.The preciseness of the colour measurements of Col-OSSOS has allowed the identification of several KBOs with outlying surface colours. These objects separated out from the rest of the neutral cloud in (g−r) versus (r−J) colours, with (g−r) colour near solar colour. Using the Gemini North telescope in Hawaii we have taken extra photometry in the i− and z−bands for three of these objects (2013 JE64, 2013 JR65 and 2014 UL225). These additional filter observations will allow us to identify any possible broadband absorption features on these object’s surfaces that may have caused their outlying surface colours. Asteroid interloper 2004 EW95 (Seccull et al., 2018), along with some Jupiter Trojans and C-type asteroids (Bus & Binzel, 2002; DeMeo & Carry,2013) have been shown to have similar near solar neutral surfaces. In this presentation we will report resultsof the griz photometry of 2013 JE64, 2013 JR65 and 2014 UL225. We will make comparisons between these results and the photometry of previously identified outlying KBOs and comment on any possible similarities.ReferencesBus, S. J., & Binzel, R. P. 2002, Icarus, 158, 146DeMeo, F. E., & Carry, B. 2013, Icarus, 226, 723Schwamb, M. E., Bannister, M. T., Marsset, M., et al. 2019, ApJS, 243, 12Seccull, T., Fraser, W. C., Puzia, T. H., Brown, M. E., & Schönebeck, F. 2018, ApJ, Letters, 855, L26Tegler, S. C., Romanishin, W., Consolmagno, G. J., & J., S. 2016, AJ, 152, 2

The low-inclination component of the classical Kuiper Belt is thought to be the only population of trans-Neptunian bodies that formed in-situ (Parker et al., 2010). This population, often referred to as the cold classical objects, exhibits a ~30% observed binary fraction, much higher than for other trans-Neptunian objects (TNOs; Noll et al., 2008). The majority of cold classicals belong to the Very Red (VR) class of the bimodal TNO compositional taxonomy (Fraser and Brown, 2012). Though recently, a population of Less Red (LR) members has been identified, exhibiting a 100% binary fraction (Fraser et al., 2017). These so-called blue binaries are thought to be survivors of a push-out process that occurred during a smooth phase of Neptune’s outward migration. Here we report 20 new (g-r) and (r-J) colours of cold classical objects gathered as part of the Colours of the Outer Solar System Origins Survey (Col-OSSOS; Schwamb et al., 2019), bringing the total sample of cold classicals with measured colours to 21 with simultaneous optical and NIR colours, and 103 cold classical TNOs with optical colours alone. In this sample, 29 objects have been identified as binary (Parker, A., personal communication).Cold classical colours span the full range of optical-NIR colours exhibited by the dynamically excited TNO populations, though they strongly favour red objects; the VR:LR ratio is ~12 compared to ~3 for the excited TNOs. Moreover, the VR cold classicals have a redder colour distribution than the VR excited TNOs, with the former exhibiting a mean (g-r)~0.95 and the latter, a mean (g-r)~0.8.The optical colour distribution of binary cold classicals is significantly different than that of the single (or unresolved) cold classical systems (see Figure 1), with the binary sample exhibiting a tail of lower spectral slopes than is found in the sample of singles. The Kolmogorov-Smirnov test comparing the optical colour distributions of the single and binary samples says that there is a only a 0.3% chance the two samples share the same colour distribution. The Col-OSSOS sample on its own shows a similar result, with a 2% probability of the null hypothesis. This argues for a different origin of some or all of the binary cold classicals over the unresolved or single objects population, and is compatible with the hypothesis that the blue binaries are contaminants having been pushed out from regions closer to the Sun. Figure 1: cumulative optical colour distributions of the single (or unresolved; solid) and binary (dashed) cold classical TNOs. The vertical line demarks the division between less red and very red compositional classes. Spectral slope is reported in percent reddening per 100 nm normalized in the V-band.

The Colours of the Outer Solar System Origins Survey (Col-OSSOS, Schwamb et al., 2019) has examined the surface compositions of Kuiper Belt Objects (KBOs) by way of broadband g-, r- and J-band photometry, using the Gemini North Hawaii Telescope. This survey showed a bimodal distribution in the colours of the objects surveyed, consistent with previous colour surveys (Tegler et al., 2016). These broadband surface colours can be considered a proxy for surface composition of these KBOs, so this survey allows the frequency of different surface compositions within the outer Solar System to be explored. The bimodality of the observed colours suggests the presence of some sort of surface transition within the Kuiper belt, perhaps due to a volatile ice-line transition in the pristine planetesimal disk that existed before Neptune’s migration. The Outer Solar System Origins Survey (OSSOS, Bannister et al., 2018), from which Col-OSSOS selected objects brighter than 23.6 r-band magnitude, has well characterised and quantified biases, so allowing for comparisons between the observations and numerical models of the Kuiper belt.By applying different colour transitions to the primordial planetesimal disk, in this work we explore the possible positions for ice line/colour transitions within the planetesimal disk that existed before Neptune’s migration. Within Schwamb et al. (2019), a simplified toy model was used to investigate the possible position of this transition. Nesvorny et al. (2020) has investigated the primordial colour fraction, in particular how it can create the inclination distribution that we see in the colours of KBOs today. In this work we use a full dynamical model of the Kuiper belt to more precisely pinpoint the possible location of this transition. We make use of the model by Nesvorny & Vokrouhlicky (2016) of Neptune’s migration from 23 au to 30 au, and the consequent perturbation of the Kuiper belt into its current form. This model allows precise tracking of the objects from their pre-Neptune migration to post-Neptune migration positions, allowing various colour transition positions in the initial disk, an example of which is shown in Figure 1, to be compared with the Col-OSSOS observations of the modern day disk.Figure 1: An example red/neutral transition at 27 au. The left plots show the objects in the primordial disk, while the right plots show the objects post-Neptune migration from the model of Nesvorny & Vokrouhlicky (2016).The OSSOS survey simulator (Lawler et al., 2018) can then be used to calculate which of the simulated objects could have been observed by OSSOS, and so selected by Col-OSSOS for surface colour observations. The colour transition within the initial disk, shown in Figure 1, is moved radially outwards through the disk and the corresponding outputs are compared with the Col-OSSOS colour observations to see which initial disk colour transition positions are consistent with the modern day Kuiper belt. We will present results combing an accurate dynamical model of the Kuiper Belt’s evolution by Nesvorny & Vokrouhlicky (2016) with Col-OSSOS photometry. We will explore multiple radial colour distributions in the primordial planetesimal disk and implications for the the positions of ice line/colour transitions within the Kuiper Belt’s progenitor populations. ReferencesBannister, M. T., Gladman, B. J., Kavelaars, J. J., et al. 2018, ApJS, 236, 18Lawler, S. M., Kavelaars, J. J., Alexandersen, M., et al. 2018, Front. Astron. Space Sci., 5, 14Nesvorny, D., Vokrouhlicky, D., Alexandersen, M., et al. 2020, AJ, in pressNesvorny, D., & Vokrouhlicky, D. 2016, ApJ, 825Schwamb, M. E., Bannister, M. T., Marsset, M., et al. 2019, ApJS, 243, 12Tegler, S. C., Romanishin, W., Consolmagno, G. J., & J., S. 2016, AJ, 152, 2

The Transneptunian Automated Occultation Survey (TAOS II) is a three robotic telescope project to detect stellar occultation events generated by TNOs. TAOS II aims to monitor about 10000 stars simultaneously at 20Hz to generate a significant event rate. The TAOS II cameras are designed to cover the 1.7 degree diameter field of view of the 1.3m telescopes with a mosaic of ten 4.5k x 2k e2v CIS 113 CMOS sensors. The CIS 113 has a back-illuminated thinned structure to provide similar performance to that of back-thinned CCDs. The CIS 113 device has 16 micron pixels with 8 outputs, with a plate scale about 0.63"/pixel. With the freedom of direct row and column addressing, star boxes with sizes of 8 x 8 pixels in each sensor can be sampled at 20 Hz or higher with a pixel rate of 1M pixel/sec per channel. The sensors, mounted on a single Invar plate, are cooled to an operating temperature of about 200K by a cryogenic cooler. The gap between two sensors is about 0.5mm. The control electronics consist of an analog part and a Xilinx FPGA based digital circuit. One FPGA is needed to control and process the signal from each CIS 113 chip. Two large PCBs were used to fanout signals from the 10 CMOS devices through the vacuum chamber wall. A synchronization circuit receives a pulse from the control building to ensure the timing error of exposures of the three cameras is within 1 ms. The cameras were delivered and installed on the TAOS telescopes in 2023 and series of tests and adjustments have been carried out to optimize the performance. In this presentation, the camera performance in the full frame mode and the window mode will be detailed. The synchronization and the adjustment among the three cameras will also be presented.

In August 2019, 2I/Borisov, the second interstellar object and first visibly active interstellar comet, was discovered on a trajectory nearly perpendicular to the ecliptic. Observations of planet forming disks and debris disks serve as probes of the ensemble properties of extrasolar planetesimals, but the passage of an active interstellar comet through our Solar System provides a rare opportunity to individually study these small bodies up close in the same ways in which we investigate objects originating from our own Outer Solar System. Ground-based observations of short period comet 67P/Churyumov–Gerasimenko revealed a coma dust composition indistinguishable from what was measured on its nucleus by the orbiting Rosetta spacecraft. Therefore when 2/I Borisov had a dust dominated tail, we attempted to study its composition with near-simultaneous griJ photometry with the Gemini North Telescope. We obtained two epochs of GMOS-N and NIRI observations in November 2019, separated by two weeks. We will report on the inferred optical-near-IR colors of 2I/I Borisov’s dust coma/tail and nucleus. We will compare our measurements to other observations of 2I/Borisov and place the interstellar comet in context with the Col-OSSOS (Colours of the Outer Solar System Survey) sample of small KBOs and interstellar object ʻOumuamua observed in grJ with Gemini North, using the same setup.

From the first phase of the high-cadence Formation of the Outer Solar System: an Icy Legacy (FOSSIL) survey, we analyzed lightcurves, ranging from one to four nights in length, of 371 trans-Neptunian objects (TNOs) for periodicity. We found 29 TNOs with periodic lightcurves, one of which is a good candidate for a close/contact binary. Another of the periodic FOSSIL TNOs could potentially have the fastest of all known TNO spin rates, with a period of 1.3 hr. We do not have total confidence in the period and thus plan to obtain a more detailed lightcurve for confirmation. The periodic TNOs have an average rotation period of 11.2 hr, close to the value obtained by Alexandersen et al., which had similar cadence, but different from other surveys. In regards to contention in the literature about whether smaller TNOs are more irregular in shape and thus have larger lightcurve amplitudes, we found that there is a weak correlation between absolute magnitude and lightcurve amplitude in a subset of 194 FOSSIL TNOs, even when using the more appropriate brightest (minimum) absolute magnitude instead of the time-averaged value.

Quaoar is a classical Trans-Neptunian Object (TNO) with an area equivalent diameter of 1,100 km and an orbital semi-major axis of 43.3 astronomical units. Based on stellar occultations observed between 2018 and 2021, an inhomogeneous ring (Q1R, Quaoar's first ring) was detected around this body. Aims. A new stellar occultation by Quaoar was observed on August 9th, 2022 aiming to improve Quaoar's shape models and the physical parameters of Q1R while searching for additional material around the body. Methods. The occultation provided nine effective chords across Quaoar, pinning down its size, shape, and astrometric position. Large facilities, such as Gemini North and the Canada-France-Hawaii Telescope (CFHT), were used to obtain high acquisition rates and signal-to-noise ratios. The light curves were also used to characterize the Q1R ring (radial profiles and orbital elements). Results. Quaoar's elliptical fit to the occultation chords yields the limb with an apparent semi-major axis of $579.5\pm4.0$ km, apparent oblateness of $0.12\pm0.01$, and area-equivalent radius of $543\pm2$ km. Quaoar's limb orientation is consistent with Q1R and Weywot orbiting in Quaoar's equatorial plane. The orbital radius of Q1R is refined to a value of $4,057\pm6$ km. The radial opacity profile of the more opaque ring profile follows a Lorentzian shape that extends over 60 km, with a full width at half maximum (FWHM) of $\sim5$ km and a peak normal optical depth of 0.4. Besides the secondary events related to the already reported rings, new secondary events detected during the August 2022 occultation in three different data sets are consistent with another ring around Quaoar with a radius of $2,520\pm20$ km, assuming the ring is circular and co-planar with Q1R. This new ring has a typical width of 10 km and a normal optical depth of $\sim$0.004. Like Q1R, it also lies outside Quaoar's classical Roche limit.

We present photometric observations and numerical simulations of 2016 SD 106 , a low-inclination ( i = 4.°8) extreme trans-Neptunian Object with a large semimajor axis ( a = 350 au) and perihelion ( q = 42.6 au). This object possesses a peculiar neutral color of g − r = 0.45 ± 0.05 and g − i = 0.72 ± 0.06, in comparison with other distant trans-Neptunian objects, all of which have moderate-red to ultra-red colors. A numerical integration based on orbital fitting on astrometric data covering eight years of arc confirms that 2016 SD 106 is a metastable object without significant scattering evolution. Each of the clones survived at the end of the 1 Gyr simulation. However, very few neutral objects with inclinations <5° have been found in the outer solar system, even in the main Kuiper Belt. Furthermore, most mechanisms that lift perihelion distances are expected to produce a very low number of extreme objects with inclinations <5°. We thus explored the possibility that a hypothetical distant planet could increase the production of such objects. Our simulations show that no 2016 SD 106 –like orbits can be produced from three Kuiper Belt populations tested (i.e., plutinos, twotinos, and the Haumea Family) without the presence of a hypothetical planet, while a few similar orbits can be obtained with it; however, the presence of the additional planet produces a wide range of large semimajor-axis/large perihelion objects, in apparent contradiction with the observed scarcity of objects in those regions of phase space. Future studies may determine if there is a connection between the existence of a perihelion gap and a particular orbital configuration of a hypothetical distant planet.

Dynamically excited objects within the Kuiper belt show a bimodal distribution in their surface colors, and these differing surface colors may be a tracer of where these objects formed. In this work we explore radial color distributions in the primordial planetesimal disk and implications for the positions of ice line/color transitions within the Kuiper belt's progenitor populations. We combine a full dynamical model of the Kuiper belt's evolution due to Neptune's migration with precise surface colors measured by the Colours of the Outer Solar System Origins Survey in order to examine the true color ratios within the Kuiper belt and the ice lines within the primordial disk. We investigate the position of a dominant, surface color changing ice-line, with two possible surface color layouts within the initial disk; (1) inner neutral surfaces and outer red, and (2) inner red surfaces and outer neutral. We performed simulations with a primordial disk that truncates at 30 au. By radially stepping the color transition out through 0.5 au intervals we show that both disk configurations are consistent with the observed color fraction. For an inner neutral, outer red primordial disk we find that the color transition can be at $28^{+2}_{-3}$ au at a 95% confidence level. For an inner red, outer neutral primordial disk the color transition can be at $27^{+3}_{-3}$ au at a 95% confidence level.

ABSTRACT We present photometric light curves of the stellar occultation event of the star UCAC4 341-187633 on 2018 August 15 by the minor planet (134340) Pluto. Photometric observations were carried out using the 2.1-m telescope at the San Pedro Mártir Observatory and the 1.3-m telescopes at Sites 2 and 3 of the Trans-Neptunian Automated Occultation Survey (TAOS II) project, and using a portable 0.4-m telescope from Bahía Asunción, Baja California Sur, Mexico. Different filters were used with the 2.1-m telescope and the TAOS II telescopes, whilst observations with the portable system were performed with no filter. The resulting light curves from the San Pedro Mártir Observatory show clear structures, with at least two bright spikes observed on ingress and one more observed on egress as the star traverses the atmosphere of the dwarf planet. The light curve from the portable telescope (440 km away) measured a longer duration for the occultation event, because the shadow of Pluto was observed at a lower latitude. Normalized light curves were created for the 2.1-m telescope, the Site 3 telescope of the TAOS II and the portable telescope. These normalized light curves show a difference in amplitude.

We present a new pipeline based on the Support Vector Machine algorithm to confirm the detection and perform classification of small solar system objects by serendipitous stellar occultations. This pipeline is designed to analyze light curves and to identify the occultation events and the classification of the occulting bodies according to their size, typically from a fraction to a few kilometers, and their distance from the Sun, typically a few tens of astronomical units. The input light curves for this pipeline were obtained from the event simulator for the Trans-Neptunian Automated Occultation Survey (TAOS II). We explore parameters affecting occultation light curves such as spectral type, apparent magnitude and finite angular size of the occulted star, angle from opposition, and readout cadence for the observations; also we assumed a Poisson noise distribution as expected from the TAOS II project. We find that occultation events, especially by trans-Neptunian objects with diameters ≥2 km are detected with 99.99%, 99.53%, and 86% efficiency for stars with a visual apparent magnitude of 12, 14, and 16, respectively at 0.05 s of exposure time. In terms of size and distance classification the overall accuracy is 94%. However, for smaller objects the confirmation and classification depends mostly upon the signal-to-noise ratio.

The Transneptunian Automated Occultation Survey (TAOS II) is a three robotic telescope project to detect stellar occultation events generated by TransNeptunian objects (TNOs). TAOS II aims to monitor about 10000 stars simultaneously at 20Hz to generate a significant event rate. The TAOS II cameras are designed to cover the 1.7 degree diameter field of view of the 1.3m telescopes with a mosaic of ten 4.5k × 2k Teledyne e2v CIS 113 CMOS sensors. The CIS 113 has a back-illuminated thinned structure to provide similar performance to that of back-thinned CCDs. The CIS 113 device has 16 micron pixels with 8 outputs, with a plate scale about 0.63"/pixel. With the freedom of direct row and column addressing, star boxes with sizes of 8 × 8 pixels in each sensor can be sampled at 20 Hz or higher with a pixel rate of 1M pixel/sec per channel. The sensors, mounted on a single Invar plate, are cooled to an operating temperature of about 200K by a cryogenic cooler. The surfaces of the sensors were mounted to be within 30 microns to maintain a flat focal plane. The gap between two sensors is about 0.5mm. The control electronics consist of an analog part and a Xilinx FPGA based digital circuit. One FPGA controls and processes the signal from each CIS 113 chip. Two large PCBs were used to fanout signals from the 10 CMOS devices through the vacuum chamber wall. A synchronization circuit receives a pulse from the control center to ensure the timing accuracy of exposures of the three cameras is within 1 ms.

Beyond the orbit of Neptune lies a sea of small icy bodies known as the Kuiper belt. The surfaces of these Kuiper Belt Objects (KBOs) have remained relatively unprocessed since their formation as a consequence of their distance from the Sun. This means that we can investigate their formation conditions in the early Solar System by studying their surfaces today. Generally, the small and most numerous KBOs are quite dim (r mag > 22), and so it is difficult to study their surfaces spectroscopically. Instead, we can use broadband photometry to take effectively very low-resolution spectra of their surfaces. When studied spectroscopically, the surfaces of smaller KBOs have generally shown very flat and featureless spectra within certain wavelength ranges. This means that broadband photometry (within those wavelength ranges) can reveal enough information to characterise the optical and near-infrared spectral slopes of these planetesimals. The Colours of the Outer Solar System Origins Survey (Col-OSSOS) has obtained optical and near-infrared broadband photometry of a sample of 92 KBOs, at unprecedented precision (~ ±0.03 mag in optical wavelengths). These broadband surface colours allow small, dynamically excited KBOs to be characterised into a bimodal colour distribution (as with previous colour surveys), along with the identification of potentially outlying surface colours. As a side effect of Col-OSSOS’s observing technique we have a sample of objects with repeated optical colours, and some repeated near-infrared colours. We also have taken additional optical photometry of a small sample of KBOs with outlying surface colours. This allows us to investigate the possibility of photometric variation across multiple epochs for this sample of objects. Col-OSSOS observed sequential broadband filters on timescales less than the typical periods of small KBOs. Therefore, we can simultaneously fit a linear lightcurve and photometric colours to our photometry and potentially rule out lightcurve effects causing photometric variations. This means that differing colours across multiple epochs implies either differing surface composition, or that our approximation of linear brightness variability across the observing sequence is invalidated. We will present this sample and discuss implications for the spectrovariable population within the Kuiper belt.

In this work, we present the general procedure for the robotic observations of the Transneptunian Automated Occultation Survey (TAOS II). The project aims to detect small TNOs (Transneptunian Objects) by serendipitous stellar occultations. To do so TAOS II will operate three 1.3 m telescopes equipped with CMOS cameras which are able to read about 10,000 stars in multiple subapertures at a 20 Hz cadence. At such rates, it will be possible to identify diffraction features in the lightcurves, helping us to estimate a distance and object size to each occultation event. TAOS II is installed in the Observatorio Astronómico Nacional in San Pedro Mártir, Ensenada, México (OAN-SPM). The site has good observing conditions, typically with around 260 useful nights per year. Here, we describe the different process to be performed in a typical observing night: system start up and shut down, monitoring observing conditions, acquisition of calibration images, field selection, pointing, camera synchronization, determination of aperture sizes and positions, and high speed image acquisition.

We present the discovery of 2013 VZ70, the first known horseshoe coorbital companion of Saturn. Observed by the Outer Solar System Origins Survey for 4.5 yr, the orbit of 2013 VZ70 is determined to high precision, revealing that it currently is in “horseshoe” libration with the planet. This coorbital motion will last at least thousands of years but ends ∼10 kyr from now; 2013 VZ70 is thus another example of the already-known “transient coorbital” populations of the giant planets, with this being the first known prograde example for Saturn (temporary retrograde coorbitals are known for Jupiter and Saturn). We present a theoretical steady-state model of the scattering population of trans-Neptunian origin in the giant planet region (2–34 au), including the temporary coorbital populations of the four giant planets. We expose this model to observational biases using survey simulations in order to compare the model to the real detections made by a set of well-characterized outer solar system surveys. While the observed number of coorbitals relative to the scattering population is higher than predicted, we show that the number of observed transient coorbitals of each giant planet relative to each other is consistent with a trans-Neptunian source.

The Transneptunian Automated Occultation Survey (TAOS II) is a blind occultation survey with the aim of measuring the size distribution of Trans-Neptunian Objects with diameters in the range of 0.3 ≲ D ≲ 30 km. TAOS II will observe as many as 10,000 stars at a cadence of 20 Hz with all three telescopes simultaneously. This will produce up to ∼20 billion photometric measurements per night, and as many as ∼6 trillion measurements per year, corresponding to over 70 million individual light curves. A very fast analysis pipeline for event detection and characterization is needed to handle this massive data set. The pipeline should be capable of real-time detection of events (within 24 hours of observations) for follow-up observations of any occultations by larger TNOs. In addition, the pipeline should be fast and scalable for large simulations where simulated events are added to the observed light curves to measure detection efficiency and biases in event characterization. Finally, the pipeline should provide estimates of the size of and distance to any occulting objects, including those with non-spherical shapes. This paper describes a new data analysis pipeline for the detection and characterization of occultation events.