The Vera C. Rubin Observatory is a new NSF/DOE-funded facility on Cerro Pachón, Chile. It houses the 8.4m Simonyi Survey Telescope and the 3.2 Gigapixel LSSTCam camera. The Observatory is in the final stages of commissioning, expected to enter operations by the end of 2025. Once operational, Rubin will execute the Legacy Survey of Space and Time (LSST). Enabled by its 9.6 square degree field of view and a cadence covering the sky every 3-4 days to ~24.5 mag, the LSST dataset will dramatically advance numerous area of astronomy, including our understanding of the Solar System by delivering the largest catalog of small bodies to date.

This talk will present the first public Solar System-related results from Rubin's early commissioning efforts. We will discuss the discovery yields, measured performance of the observatory, early comparison to predictions, and talk through the expectations for further data during commissioning's Science Validation surveys. With a steady stream of public solar system discoveries expected to start in late commissioning, small bodies are likely to be one of the first areas of highly impactful early science. We hope this talk will help prepare the Solar System community for those imminent opportunities, and illustrate the transformational capabilities that Rubin is about to bring.

How to cite: Jurić, M., Heinze, A., Kurlander, J., Bernardinelli, P., Moeyens, J., Greenstreet, S., Bellm, E., and Sullivan, I.: Initial Rubin Solar System results: Performance, first discoveries, and expectations for operations, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-242, https://doi.org/10.5194/epsc-dps2025-242, 2025.

The Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) will provide an unprecedented dataset to explore the Solar System’s small body inventory. The survey will discover nearly 4 million new Solar System bodies. This is nearly 3 times the current inventory of main-belt asteroids and 6 times more trans-Neptunian objects than are currently known today.  The LSST will go beyond just discovery; with a 10-year baseline, the survey will be able to measure broad-band optical colors and phase curves and capture episodes of cometary activity, orbit changes, rotational breakup events, and rotational brightness variations. Planetesimals are the bricks and mortar left over after the construction of planets. Their compositions, shapes, densities, rotation rates, and orbits help reveal their formation history, the conditions in the planetesimal-forming disk, and the processes active in the Solar System today. LSST will transform our current view of the Solar System and let us peer back into the Solar System’s past like never before.

The LSST Solar System Science Collaboration (SSSC) has identified key software products/tools that the Rubin user community must develop to achieve the planetary community’s LSST science goals. Near the top of the SSSC’s software roadmap is a Solar System survey simulator to enable comparisons of model small body orbital and size/brightness distributions to LSST discoveries. For the past several years, we have been developing Sorcha, an open-source community LSST Solar System Survey Simulator handling the scale of the LSST data and the ability to predict on-sky positions for billions of simulated Solar System objects. Sorcha takes a model Solar System small body population and uses the pointing history, observation metadata, and expected Rubin Observatory detection efficiency to output what LSST should find so that the numbers and types of simulated detections can be directly compared to the number and types of real small bodies found in the actual LSST survey.  In this presentation, we will provide an overview of Sorcha, highlight the software design and architecture, provide a demonstration of how Sorcha works, and present key science cases for Sorcha in the context of early LSST Solar System science during the first year of the survey

How to cite: Schwamb, M., Meritt, S., Fedorets, G., Cornwall, S., Bernardinelli, P., Jurić, M., Holman, M., Kurlander, J., Eggl, S., Oldag, D., West, M., Kubica, J., Murtagh, J., Jones, L., Yoachim, P., and Lyttle, R. and the Sorcha Team: Sorcha: A Solar System Survey Simulator for the Legacy Survey of Space and Time, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-1075, https://doi.org/10.5194/epsc-dps2025-1075, 2025.

The NSF-DOE Vera C. Rubin Observatory is a new 8m-class survey facility presently being commissioned in Chile, expected to begin the 10yr-long Legacy Survey of Space and Time (LSST) by the end of 2025. Using the purpose-built Sorcha suvey simulator, and near-final observing cadence, we perform the first high-fidelity simulation of LSST’s solar system catalog for key small body populations. We show that the final LSST catalog will deliver over 1.1 billion observations of small bodies and raise the number of known objects to 1.27E5 near-Earth objects, 5.09E6 main belt asteroids, 1.09E5 Jupiter Trojans, and 3.70E4 trans-Neptunian objects. These represent 4-9x more objects than are presently known in each class, making LSST the largest source of data for small body science in this and the following decade. We characterize the measurements available for these populations, including orbits, griz colors, and lightcurves, and point out science opportunities they open. Importantly, we show that ~70% of the main asteroid belt and more distant populations will be discovered in the first two years of the survey, making high-impact solar system science possible from very early on. We make our simulated LSST catalog publicly available, allowing researchers to test their methods on an up-to-date, representative, full-scale simulation of LSST data.

How to cite: Kurlander, J. and the Sorcha Predictions Team: Predictions of the LSST Solar System Yield: Near-Earth Objects, Main Belt Asteroids, Jupiter Trojans, and Trans-Neptunian Objects, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-418, https://doi.org/10.5194/epsc-dps2025-418, 2025.

The giant planet region of the Solar System (5.2 au < a < 30.1 au) can be a highly chaotic and dynamic environment of small body science, whose resident minor bodies can offer unique insights into both early Solar System formation and present-day evolution processes. Co-orbiting with Neptune in a 1:1 resonance, the Neptune Trojans (NTs) are a family of objects that can be dynamically stable on the order of billions of years (e.g., Lin et al., 2022). Numerical studies show that Neptune’s outwards migration is capable of capturing and retaining NTs (e.g., Gomes & Nesvorný, 2016), implying that the present day observed population may retain some information about the primordial protoplanetary disk conditions. Further in from Neptune, the Centaurs are a class of objects on giant-planet-crossing orbits, evolving inwards due to their many gravitational perturbations. They are an intermediate population, with colour distributions similar to smaller trans-Neptunian Objects (TNOs) (e.g., Wong & Brown, 2017), and physical sizes more typical of the nuclei of Jupiter family comets (e.g., Fernández et al., 2013). Understanding Centaur properties in ensemble is therefore a means of providing insight into the evolution of dynamically scattering TNOs into present day comets, as well as probing the evolution of how their surfaces are processed.

Over decades of observations, the Minor Planet Center (MPC) only notes <30 NTs, and∼300 Centaurs to date. These small sample sizes are set to be revolutionised with dawning of the Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST). With first light having already occurred in July, the LSST is scheduled to commence operations in late 2025. One of its main science goals is to ”create an inventory of the Solar System”, cataloguing as many objects as possible across all orbital classes. This is achieved through its unprecedented combination of depth (m_r ∼24.7), coverage in 6 broadband optical/NIR filters (ugrizy), and its observing cadence of 30s visits to 18,000 deg² of the southern hemisphere every three nights over its full decadal observational baseline. Early estimates for the LSST’s performance predicted an order of magnitude increase in Near Earth Objects, Main Belt Asteroids, Jupiter Trojans, and TNOs (Ivezić et al., 2007; LSST Science Collaboration et al., 2009; Jones et al., 2015; Ivezć et al., 2019), with more refined estimates detailed in Kurlander et al. (2025a). Predictions for the LSST’s discovery metrics, including the total number of observations available per object, when they are discovered, and how many will be discovered, are vitally important in understanding the potential for small body science within the LSST through light curve, phase curve, and surface colour studies. Further, such predictions are crucial in understanding the gaps in the LSST’s observation cadence, which will enable the design of follow-up observational campaigns to supplement and bolster the LSST.

In this work, we present the very first estimates for the Neptune Trojan and Centaur discoveries within the LSST. We use the best available dynamical models for both populations (Nesvornŷ et al., 2019; Lin et al., 2021), and absolute magnitude and colour distributions drawn from Dark Energy Survey Neptune Trojan discoveries (Bernardinelli et al., 2025) and Pan-STARRS1 Centaur discoveries (Kurlander et al., 2025b). We use the new high-fidelity survey simulator Sorcha (Merritt et al., In Press; Holman et al., In Press) in order to generate ephemerides using the in-built N-body integrator ASSIST (Holman et al., 2023) (itself an extension of REBOUND, Rein & Liu, 2012; Rein & Spiegel, 2015). Sorcha is able to take the most recent LSST cadence simulations (SCOC, 2024), in order to forward bias these objects and simulate LSST discoveries. We highlight the year 1 science potential for both populations, including discovery numbers, and the prospects for light/phase curve and surface colour studies. The implications for understanding the Neptune Trojan colour-inclination dependency, as well as assumptions of symmetry of the L4 and L5 clouds are also discussed. Finally, we will discuss Centaur activity searches in the era of the LSST.

How to cite: Murtagh, J., Schwamb, M., Bernardinelli, P., Lin, H. W., Merritt, S., Kurlander, J., Cornwall, S., Jurić, M., Fedorets, G., Holman, M., Eggl, S., Nesvorný, D., Volk, K., Jones, R. L., Yoachim, P., Moeyens, J., Kubica, J., Oldag, D., West, M., and Chandler, C. O.: The Captured and the Crossing: Predictions for the LSST Discovery Yields for Neptune Trojans and Centaurs, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-719, https://doi.org/10.5194/epsc-dps2025-719, 2025.

Cometary activity — visible as tails or comae — offers a fleeting glimpse into the icy, volatile-rich small bodies of our solar system. Yet, despite the anticipated discovery of five million minor planets by the Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST; Ivezic et al. 2019; Vera C. Rubin Observatory LSST Solar System Science Collaboration et al. 2021; Kurlander et al. 2025), LSST’s data products are not specifically designed to identify visible cometary activity such as tails or comae in its nightly torrent of images. Enter Rubin Comet Catchers, a new Citizen Science program designed to unlock this potential. By combining artificial intelligence with the power of human eyes, volunteers will help identify active small bodies hiding in plain sight among known asteroids, Centaurs, near-Earth objects, and beyond.

Building on the remarkable success of the Active Asteroids Citizen Science program, which discovered some 30 previously unknown active minor planets, including the first AI-discovered active asteroids and an active near-Earth object (Chandler et al. 2024a, 2024b; Sedaghat et al. 2024), Rubin Comet Catchers will extend this proven approach to LSST’s unprecedented dataset. Volunteers will inspect daily-updated images using an intuitive Zooniverse interface, supported by a machine learning pipeline that filters and prioritizes candidates. Promising discoveries will be escalated to expert review, followed by targeted archival searches and professional telescope observations to confirm activity and submit new comets to the Minor Planet Center.

In this presentation, we will introduce the Rubin Comet Catchers project, describe our AI-enhanced discovery workflow, and showcase initial results from commissioning and early LSST data. We will also highlight the scientific questions this project is uniquely positioned to address — ranging from activity occurrence rates across dynamical classes to the identification of new populations of active small bodies — and invite the global community to join us in the search.

How to cite: Chandler, C. O., Frissell, M., Morato, N., Kurlander, J., Vavilov, D., Trujillo, C., Jurić, M., Connolly, A., Higgs, C., Lintott, C., Oldroyd, W., Sedaghat, N., Burris, W., Kueny, J., Hsieh, H., DeSpain, J., Farrell, K., Bernardinelli, P., Magbanua, M. J. M., and Sheppard, S. and the Rubin Comet Catchers: The Rubin Comet Catchers Citizen Science Project: Launch and Initial Results, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-1189, https://doi.org/10.5194/epsc-dps2025-1189, 2025.

Asteroids’ phase curves – the dependence of their brightness on the solar phase angle – carry information about asteroid surface properties in terms of light scattering. Phase curves are related to surface roughness, albedo, and taxonomic classification. In its basic form, a phase curve plots an asteroid’s brightness reduced to unit distance from the Sun and the Earth as a function of the phase angle (Sun–asteroid–Earth). Observed phase curves fitted with a theoretical model serve to estimate the absolute magnitude H (Bowell et al. 1989; Muinonen et al. 2010). However, an asteroid’s brightness depends not only on the phase angle; it also varies with changing geometry and rotation, so these factors inevitably affect real phase curves. Several techniques have been used to account for these effects (Muinonen et al. 2020, 2022; Carry et al. 2024). 

In our approach, we use the light curve inversion method of Kaasalainen & Torppa (2001); Kaasalainen et al. (2001), where the phase curve is expressed as a combination of linear and exponential functions with three parameters that are optimized during the modeling. This way, the shape and geometry effects are
removed, and the phase curve is affected only by measurement errors. When observations in different filters are available, the color shift between the data sets is another information that we extract from the data. Moreover, phase curves are wavelength-dependent, so that each filter can have different parameters, and we can study the phase reddening effects.

In the case of LSST of the Vera Rubin Observatory, asteroid photometry will be available in six filters covering wavelengths 320–1050 nm. For a typical main-belt asteroid, 200–300 individual measurements will be taken over 10 years of the survey. Fitting of the phase function will be treated inside the processing pipeline, so the H and G12 parameters for each filter will be provided as part of the data releases. However, for those asteroids for which the light curve inversion will provide a unique model, it will be possible to derive more precise phase curves for all six filters.

As a preparatory work before the LSST data will be available, we processed asteroid photometry from these surveys: Catalina, Mt. Lemmon, Pan-STARRS, ZTF, ATLAS, TESS, ASAS-SN, USNO, and Gaia DR3. From about 330,000 processed asteroids, we were able to derive unique spin solutions and corresponding convex shape models for about 23,000. The most abundant data set was ATLAS photometry in cyan and orange filters with hundreds of data points per asteroid. For a subsample of about 15,000 asteroids with abundant ATLAS photometry, we used the model to remove outlying photometric points and derived precise phase curves from ATLAS observations in two filters. This allowed us to compare colors and phase curves of different collisional families, taxonomic types, etc. We also searched for phase coloring effects (Alvarez-Candal 2024; Wilawer et al. 2024; Colazo et al. 2025).

The left plot below shows photometric data of asteroid (1495) Helsinki from eight observatories collected over the past two decades. The brightness was reduced to unit distances from the Sun and the Earth and is shown in relative intensity units. The phase curves are affected by different filters, rotational variation, and geometry effects related to changing aspect. The right plot shows the mean phase curve obtained as a result of light curve inversion and residuals scattered around the mean curve.

References

Alvarez-Candal, A. 2024, A&A, 685, A29
Bowell, E., Hapke, B., Domingue, D., et al. 1989, in Asteroids II, ed. R. P. Binzel, T. Gehrels, & M. S. Matthews (Tucson: University of Arizona Press), 524–556
Carry, B., Peloton, J., Le Montagner, R., Mahlke, M., & Berthier, J. 2024, A&A, 687, A38
Colazo, M., Oszkiewicz, D., Alvarez-Candal, A., et al. 2025, Icarus, 436, 116577
Kaasalainen, M. & Torppa, J. 2001, Icarus, 153, 24
Kaasalainen, M., Torppa, J., & Muinonen, K. 2001, Icarus, 153, 37
Muinonen, K., Belskaya, I. N., Cellino, A., et al. 2010, Icarus, 209, 542
Muinonen, K., Torppa, J., Wang, X. B., Cellino, A., & Penttilä, A. 2020, A&A, 642, A138
Muinonen, K., Uvarova, E., Martikainen, J., et al. 2022, Frontiers in Astronomy and Space Sciences, 9, 821125
Wilawer, E., Muinonen, K., Oszkiewicz, D., Kryszczy´nska, A., & Colazo, M. 2024, MNRAS, 531, 2802

How to cite: Durech, J. and Hanus, J.: Asteroid phase curves reconstructed with light curve inversion – prospects for LSST, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-96, https://doi.org/10.5194/epsc-dps2025-96, 2025.

Currently, there are twenty known Venus co-orbital asteroids, but only one has an eccentricity (e) lower than 0.38 (Carruba et al. 2024; Pan & Gallardo 2024 and references therein). This distribution is likely an observational bias, as asteroids with higher eccentricities may come closer to Earth, making them easier to detect. Three known co-orbitals can potentially soon become PHAs (Carruba et al. 2025). The main objective of this work is to assess the threat that the undetected Venus co-orbital population may pose to Earth and to investigate their detectability.

Fig. (1): Left panel: the distribution in the (H, e) plane of known asteroids near Venus (blue full circles) and its co-orbital asteroids (red stars). Right panel: the distribution of 14382 simulated NEAs obtained from the NEOMOD3 model (black dots).

The expected orbital distribution of near-Earth objects (NEAs) in the vicinity of Venus obtained using the NEOMOD3 model (Nesvorný et al. 2024) does not show a dynamical preference for producing asteroids with high eccentricities (Fig. (1)). While the left panel shows that the majority of known co-orbitals have e > 0.38, the right panel reveals a large simulated population with e < 0.38. This suggests that observational biases are the most likely explanation for the lack of detection of low-eccentricity co-orbitals.

Pan & Gallardo (2024) recently developed a semi-analytical model to describe the coorbital motion in the 1:1 resonances. This permits describing the structure of the resonance under the assumption that the orbital elements of the asteroid remain fixed for a short period. Different types of coorbital orbits are possible, including tadpole (TL₄ and TL₅), horseshoe (H), and retrograde satellites (RS) orbits, compound configurations such as H-RS and T-RS, as well as transitions between these configurations. Known Venus coorbitals typically alternate between these configurations in a co-orbital cycle of approximately (12000 ± 6000) years.

Fig. (2): Projections in the (σ, a) plane of the Hamiltonian levels and the output of numerical simulations (black dots) for an asteroid in a TL₄ configuration (top left panel), in an RS orbit (top right panel), in an HRS configuration (bottom left panel) and a TRS orbit (bottom right panel).

To validate the Pan & Gallardo (2024) model, Carruba et al. (2025) applied it to the initial conditions of the 20 known Venus coorbitals and compared the results with 1000-year numerical simulations. Fig. (2) compares the projections in the (σ, a) plane of the Hamiltonian levels with the orbital evolution obtained in the numerical simulations for asteroids in different coorbital configurations (TL₄, RS, HRS, and TRS). The agreement between the semi-analytical model and the numerical simulations suggests that the model can be used to generate initial conditions for undetected Venus coorbitals.

To assess the collision risk, Carruba et al. (2025) performed 36000-year numerical simulations for several fictitious co-orbital asteroid clones distributed on a grid of initial eccentricity and inclination values. The simulations monitored close encounters with Earth, defined as an orbital distance smaller than the radius of Earth's Hill sphere, and tracked the minimum orbital intersection distance (MOID).

Fig. (3): Contour plot of the number of close encounters with Earth as a function of the initial (e, inc) values. The black stars display the location of the real co-orbitals of Venus with an MOID with Earth of 0.0005 au or less. The red stars show the orbital location of five test particles at e < 0.38 that experienced low MOIDs in our simulations.

Fig. (3) shows a contour map of the minimum MOID with Earth in the initial plane (e, inc). As expected, most close encounters occur near e = 0.38. However, there is a significant region in phase space at lower eccentricities (e < 0.38) where potential coorbitals may experience several close encounters and possibly collisions with Earth. 

Carruba et al. (2025) also investigated the observability of these potential undetected coorbitals from Earth, focusing on observing programs of the Vera C. Rubin Observatory. They analyzed a statistical sample of test particles that experienced low MOIDs with Earth, identified by the dashed line in Fig. (3). For each object, they computed ephemerides from the Vera C. Rubin Observatory site, applying sequential visibility filters: objects above the horizon, with elevation > 20◦ and apparent magnitude < 23.5. We calculated the "visibility percentage" – defined as the fraction of total ephemeris entries that satisfy all observability criteria – as a function of orbital elements. The analysis reveals a strong positive correlation between eccentricity and visibility percentage, with higher eccentricity objects being observable longer. 

Fig. (4): Fig. 9: Visibility percentage of Venus co-orbital asteroids as observed from the Rubin Observatory site as a function of orbital parameters.

Finally, observations conducted from Venus orbit, looking away from the Sun, could significantly improve the detection of these bodies. A Venus-based observer would have more favorable and consistent opportunities to detect and track co-orbital objects, although still subject to fundamental visibility limitations due to solar elongation limits. Proposed missions include space telescopes orbiting the Sun-Venus L₂ Lagrange point and telescope constellations such as the CROWN mission (Zhou et al. 2022, Fig. (5)). Such missions could be crucial to map and discover all the still “unseen” PHAs among Venus co-orbital asteroids.

Fig. (5): The CROWN telescope constellation in the Sun-Venus three-body system. Adapted from Zhou et al. (2022).

References

Carruba, V., Moreira Morais, M. H., Mourão, D. C., et al. 2024, RNAAS, 8, 213.

Carruba, V., Di Ruzza, S., Caritá, G., et al. 2025, Icarus, A116508.

Carruba, V., Sfair R., Araujo R. A. N.. et al. 2025, A&A, under review.

Nesvorný, D., Vokrouhlický, D., Shelly, F., et al. 2024, Icarus, 417, 116110.

Zhou, X., Li, X., Huo, Z., Meng, L., & Huang, J. 2022, Space: Science & Technology, A9864937.

How to cite: Carruba, V., Sfair, R., Araujo, R. A. N., Winter, O. C., Mourão, D. C., Di Ruzza, S., Aljbaae, S., Caritá, G., and Domingos, R. C.: The invisible threat: Assessing the collisional hazard posed by the undiscovered Venus co-orbital asteroids, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-25, https://doi.org/10.5194/epsc-dps2025-25, 2025.

In collaboration with the Legacy Survey of Space and Time (LSST) Solar System Collaboration (SSSC) and the Canadian Astronomy Data Centre (CADC), the Can-Rubin team is developing a new communication platform designed to meet the modern needs of the Solar System research community. Called Research Announcements for the Solar System (RAFTs), this system is intended to streamline the sharing of discoveries, observations, and updates during the fast-moving era of wide-field time-domain surveys like the Vera C. Rubin Observatory LSST. RAFTs are intended to address the unique needs of the Solar System research community in the era of large-scale surveys (such as LSST), providing a streamlined, moderated system for the timely sharing of observational alerts with announcements that are concise, scientifically relevant, and permanently archived. Hosted by the CADC, RAFTs will be freely accessible and easily discoverable with permanent DOIs assigned to each.

Each announcement will feature a machine-readable section to facilitate rapid follow-up, and will be integrated with the LSST community forum to encourage further collaborations and engagement. The system will also feature a moderation process to help maintain scientific relevance and quality. The announcements are expected to be brief, relevant, and may be urgent. While urgency is not a requirement for publication, the RAFTs platform will be particularly well-suited for time-sensitive discoveries that benefit from prompt visibility and potential follow-up. The system is designed to be scalable, with the capacity to handle an increased volume of discoveries expected from the LSST. We will present a brief demonstration of the (in development) software interface, highlighting its user-friendly design and functionality for the community.

How to cite: Buchanan, L., Fraser, W., Kavelaars, J., Lister, T., Hsieh, H., Major, B., Burke, J., Zautkin, S., Kakadiya, A., and Goliath, S.: Research Announcements for the Solar System, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-1092, https://doi.org/10.5194/epsc-dps2025-1092, 2025.

In the two centuries that scientists have been working to detect and characterize solar system bodies, progressive improvements in telescope and detector technology have greatly enhanced our capabilities (see Figure 1 for the historical progression of minor planet discovery magnitudes). However, we are reaching the physical limits of detectors and the practical engineering limits of telescopes, and since the objects we are searching for are moving, we cannot simply take longer exposures to increase our image depth. How, then, can we continue to make progress?

The standard procedure for detecting moving objects fainter than the single-image detection threshold, called shift-and-stack, has most often been limited to the regime where an object’s proper motion remains linear, because nonlinear motion drastically increases the complexity of the problem. This limitation effectively means that the stacks must be done on data taken within a single night, thus limiting the depth of search we can achieve.

In this talk I present heliostack, an algorithm that enables shift-and-stack searches for minor planets over extended time baselines, and apply it to archival data from the Hubble Space Telescope taken over a timespan of multiple days. By increasing the time baseline accessible to shift-and-stack, we will be able to find fainter solar system objects in carefully-selected segments of data from space telescopes, and surveys with sparser cadences such as the Dark Energy Survey (DES), or the upcoming Legacy Survey of Space and Time (LSST), pushing into a new regime in Figure 1.

Figure 1: Visual magnitude of all numbered objects listed in the Minor Planet Center, as viewed from the Geocenter at the epoch of discovery.

How to cite: Napier, K., Holman, M., Lin, H.-W., and Ruch, T.: heliostack: A Novel Approach to Minor Planet Detection, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-989, https://doi.org/10.5194/epsc-dps2025-989, 2025.

Abstract. TailKit is a new software suite developed as part of the Italian in-kind contribution to the Vera C. Rubin Observatory, designed to detect and characterize cometary dust environments using LSST data. TailKit generalizes and extends the capabilities of a modeling approach previously presented in [1,2], which has been successfully applied to fit the dust morphology of cometary comae and tails in a series of ground-based images. Developed in alignment with the recommendations of the LSST Solar System Science Collaboration, the software will be publicly available through Rubin platforms and integrated with alert brokers, enhancing LSST's scientific return and enabling rapid follow-up of dynamically new comets, including potential targets for ESA's Comet Interceptor mission.

Introduction. The Rubin Observatory LSST will provide an unprecedented view of the dynamic Solar System, with a particular impact on the detection and tracking of active small bodies. Our group, already engaged in supporting ESA's Comet Interceptor mission, is contributing a software infrastructure,TailKit,as part of Italy’s in-kind contribution to the LSST project. 

Core Modeling Framework and Implementation. TailKit is a dedicated software tool developed to analyze and characterize the dust environments of comets through quantitative modeling of their coma and tail morphology. At its core lies a statistical dust tail simulation model [1,2], which reconstructs the observed brightness distribution by considering the probabilistic behavior of individual dust particles ejected from the cometary nucleus. The model simulates the dynamical evolution of dust grains under the influence of solar radiation pressure and gravitational forces, incorporating a size-dependent β parameter that modulates the trajectory of each particle. The key innovation of the approach is the use of a minimal set of three free parameters, which are finely tuned to reproduce the observed dust features in order to match the observed isophotes. The parameters are:  i) Dust ejection velocity, potentially varying with time and heliocentric distance; ii) Dispersion of the β parameter, representing the spread in particle sizes and response to solar radiation; iii) Heliocentric distance dependence of the dust mass loss rate, typically expressed as a power-law, and linked to nucleus activity and size.

These parameters are physically motivated and correlated with the nucleus size, enabling an efficient and scalable fitting procedure. The model is built upon a supervolatile-driven activity hypothesis, in which the sublimation of volatiles such as CO, CO₂, and CH₄ at large heliocentric distances drives early cometary activity. This is especially relevant for dynamically new comets (DNCs) and long-period comets that will be observed by Rubin LSST at larger distances [3].

The suite fits coma and tail morphologies in LSST alert cut-out and survey images to derive: a) Tail orientation and extent; b) Afρ and  dust  optical depth; c) Time-dependent dust size distribution, emission velocity and loss rate. Where time-series images are available, the software tracks the evolution of activity. Results are output as science-ready tables suitable for ingestion by Rubin databases and alert brokers such as SNAPS.

Development status. TailKit has been developed to meet professional programming standards, with clear modular structure, comprehensive documentation, and test coverage. The simulation engine is designed for parallel execution, allowing the exploration of a large grid of parameter combinations over multiple cores or computational nodes. This enables rapid convergence toward the parameter set that minimizes residuals between model and observations, even when analyzing dozens of comets per night. Thanks to its flexibility, robustness, and integration with LSST alert systems and databases, TailKit represents a powerful tool for both automated large-scale surveys and targeted cometary science campaigns. Indeed, we are testing the tool on proprietary images of over 20 comets collected with the Telescopio Nazionale Galileo (TNG, La Palma), which happens to have a spatial scale similar to LSST (0.2”/pixel) [4].

Integration with LSST Infrastructure and Open Access. TailKit will be deployed via Rubin’s Science Platform and shared repositories, enabling community use and collaborative development. This contribution is developed in alignment with the LSST Informatics and Statistics Collaboration and fulfills the criteria for international data rights acquisition by Italy through in-kind work.

Conclusion. In this talk, I will present the TailKit software suite and its modeling core in detail, focusing on the methodology and computational implementation. I will also show the first results obtained from a fully automated model optimization on a large sample of comets, using images acquired at the TNG. These results demonstrate TailKit’s potential for deriving key dust environment properties with minimal human intervention, supporting statistical studies ahead of Rubin LSST's operational phase.

This project is supported by ASI agreement n. 2020-4-HH.0 (and Addendum). It is developed within the LSST Solar System and Informatics and Statistics Science Collaborations and the INAF/LSST data rights agreement.

References. [1] Fulle, M. et al. 2010, Astronomy & Astrophysics, 522, A63; [2] Fulle M. et al., 2022, MNRAS, 513, 5377; [3] Inno, L. et al. 2025, Icarus, Volume 429, id.116443 [4] Bertini I. et al. in preparation.

How to cite: Inno, L., Bertini, I., Fulle, M., Rotundi, A., Giordano Orsini, M., Ferone, A., Fiscale, S., Tonietti, L., Della Corte, V., Mazzotta Epifani, E., Graoppasonni, C., Ammanito, E., and Sindoni, G.: TailKit: An Italian In-Kind Software for Rubin LSST to Detect and Characterize Cometary Dust Activity, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-1510, https://doi.org/10.5194/epsc-dps2025-1510, 2025.

We are operating the Solar System Notification Alert Processing System (SNAPS), a downstream broker that presently ingests alerts from the Zwicky Transient Facility (ZTF), and will soon from the Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST). SNAPS serves several purposes that together enable a wide range of science cases.

(1) SNAPS is a clearinghouse for data from these surveys. We also presently serve some TESS data, and other large-scale databases will soon be ingested. A community user can query object(s) of interest and receive data records, derived properties (such as color and rotational period), and ancillary data (for example, orbital elements).

(2) We have several tools that detect unusual asteroids in the SNAPS database. These can be population outliers (objects whose intrinsic properties are unusual compared to other small bodies) or individual outliers (objects whose properties change with time). An example of the former case is an object with a very large lightcurve amplitude, and an example of the latter case is an active asteroid.

To date we have published papers the SNAPS architecture, first data release, and first science results (Trilling et al. 2023); on computational approaches (Gowanlock et al. 2021, 2022); on signal processing (Kramer et al. 2023, Gowanlock et al. 2024b); and on outlier detection (Gowanlock et al. 2024a). A number of additional papers are in progress..

In this presentation we will briefly summarize our infrastructure capabilities, including recent updates since the last DPS. We will highlight some of our most recent science highlights. Finally, we will present an assessment of our LSST readiness, including demonstrating tools that the community can use to interact with SNAPS.

This work is funded in part by the Arizona Board of Regents Technology and Research Initiative Fund, and by NASA and NSF grants to DET and MG.

Gowanlock et al. 2021, Astronomy and Computing, 3600472

Gowanlock et al. 2022, Astronomy and Computing, 3800511

Gowanlock et al. 2024a, AJ, 168, 56

Gowanlock et al. 2024b, AJ, 168, 181

Kramer et al. 2023, Astronomy and Computing, 440071

Trilling et al. 2023, AJ, 165, 111

How to cite: Trilling, D., Gowanlock, M., Reddy Munugala, R., Kramer, D., Chernyavskaya, M., Clark, E., Chappus, S., Franklin, S., Johnson, G., Metcalf, C., and Mule, G.: The Solar System Notification Alert Processing System (SNAPS): Infrastructure updates, ZTF science, and LSST readiness, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-736, https://doi.org/10.5194/epsc-dps2025-736, 2025.

We present a proposed Vera C. Rubin Observatory Deep Drilling micro-survey of the Kuiper Belt to investigate key properties of the distant solar system. Utilizing 30 hours of Rubin time across six 5-hour visits over one year starting in summer 2026, the survey aims to discover and determine orbits for up to 730 Kuiper Belt Objects (KBOs) to an  r-magnitude of 27.5. These discoveries will enable precise characterization of the KBO size distribution, which is critical for understanding planetesimal formation.  By aligning the survey field with NASA's New Horizons spacecraft trajectory, the micro-survey will facilitate discoveries for the mission operating in the Kuiper Belt.  Modelng based on the Outer Solar System Origin Survey (OSSOS) predicts at least 12 distant KBOs observable with the New Horizons LOng Range Reconnaissance Imager (LORRI) and approximately three objects within 1~au of the spacecraft, allowing higher-resolution observations than Earth-based facilities. LORRI's high solar phase angle monitoring will reveal these objects' surface properties and shapes, potentially identifying contact binaries and orbit-class surface correlations. The survey could identify a KBO suitable for a future spacecraft flyby.
The survey's size, depth, and cadence design will deliver transformative measurements of the Kuiper Belt's size distribution and rotational properties across distance, size, and orbital class. Additionally, the high stellar density in the survey field also offers synergies with transiting exoplanet studies. 

How to cite: Kavelaars, J., Buie, M., Fraser, W., Peltier, L., Benecchi, S., Porter, S., and Verbiscer, A. and the Rubin Solar System Deep Drilling Field Proposal Team: An Extremely Deep Rubin Survey to Explore the Extended Kuiper Belt and Identify Objects Observable by New Horizons., EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-444, https://doi.org/10.5194/epsc-dps2025-444, 2025.