Kickstarter Science Colloquium

Science
#1

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Kickstarter Science Colloquium

The first in our planned series of colloquia featuring recent work in preparation for science with LSST! Everyone is encouraged to attend.

Speakers:

“Trailblazer: An Open Data Repository for Satellite-Streaked Images”
By Meredith Rawls and Dino Bektesevic
and
“Detection vs interpretation, kilonovae with lsst.”
By Fabio Ragosta

See abstracts below for details

Monday Oct 3, 2022

16:30 - 17:30 UTC
9:30 - 10:30am PDT
12:30 - 1:30pm EDT
6:30 - 7:30pm CEST

Meeting link: Launch Meeting - Zoom

Trailblazer: An Open Data Repository for Satellite-Streaked Images

Meredith Rawls and Dino Bektesevic

An increasing population of commercial satellites is significantly impacting ground-based astronomical observations. To address this, we have built a new Trailblazer web portal, which aims to enable quantitative studies of streaks from satellites in images as the satellite population changes. Trailblazer is written in Python and Django, and allows users to upload and retrieve images affected by satellite streaks. Trailblazer stores uploaded FITS images in the cloud and saves key header information in a metadata database. Users can run queries to find satellite-streaked images by date and time, observer location, sky position, telescope, instrument, and band or filter. Images and metadata may be accessed through a RESTful API or a web query interface. To better disseminate the impact of satellite streaks on astronomy, each image also appears in a gallery for users to browse. Trailblazer is designed to be accessible to astronomers and other stakeholders to collaborate on mitigating the impact of satellite streaks, and is a cornerstone of SatHub at the new International Astronomical Union (IAU) Centre for the Protection of the Dark and Quiet Sky for Satellite Constellation Interference (CPS). Trailblazer launched in June 2022 thanks to funding from the LSSTC Kickstarter Grant Program, which enabled us to pay undergrads for software development. Check it out and upload your satellite photobombs: https://trailblazer.dirac.dev.

Detection vs interpretation, kilonovae with lsst.

Fabio Ragosta

The search for kilonova (KN) emissions in the transient sky is one of the main challenges of the multi-messenger astronomy and thanks to the discovery of the first electromagnetic counterpart, named AT2017gfo (referred as GRB170817A or GW170817), we had the possibility to have the most reliable description of the physics that drives this type of phenomena.

The search of the EM counterpart of a GW source is made extremely arduous both by the size of the error areas returned by the interferometers and by the observational properties of these objects which are very rapid and rare

Wide Field surveys, such as LSST, can represent the perfect tool to tackle these problems, due to their cadence and the big area they will screen.

In this talk, I will present an analysis on the detectability of KNe emission through LSST survey. This study will probe the possibility with such surveys to have a detailed census of these events and to have more constraints on their properties (e.g. opacity, ejecta mass and velocity).

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#2

passcode?

#3

found it on Slack…

#4

Glad you were able to find the link Bob, here are the details for the record:
Meeting ID: 813 2118 7460
Passcode: 561240

#5

For future reference, recordings of all of the Kickstarter Colloquia can be found on the program website here.

And here is the direct link to the recording from this week’s colloquium:

1 Like
#6

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Kickstarter Science Colloquium

Our next Kickstarter Science Colloquium will feature:

Occultin - An Interface for the Reduction of Stellar Occultations Data Based on SORA
By G. Benedetti-Rossi

Kilonovae with Rubin: From Alerts to Science
By Tomas Ahumada

The Effect of Vera C. Rubin Observatory Filter and Return Time Selections on Kilonova Detectability
By Cristina Andrade

Tuesday Oct 11, 2022
22:00 - 23:00 UTC
3 - 4pm PDT
6 - 7pm EDT
Midnight - 1am CEST
11am - noon + 1day NZTZ

Meeting link: https://us02web.zoom.us/j/81492910523?pwd=VEsxRUVacE92cTQyKzlYUURlWDR1Zz09

Occultin - An Interface for the Reduction of Stellar Occultations Data Based on SORA

G. Benedetti-Rossi[1,2], R. C. Boufleur[2,3], M. Fraiz[2,4], J. V. Alcantara-Pimenta[2,5], IT-Team[2,6]

1 Grupo de Dinâmica Orbital e Planetologia - GDOP/UNESP;
2 Laboratório Interinstitucional de e-Astronomia e INCT do e-Universo;
3 Observatório Nacional;
4 Escola de Matemática Aplicada - Fundação Getúlio Vargas,
5 Instituto de Física de São Carlos - IFSC/USP,
6 Infax

Tecnologia e Sistemas
Stellar occultation is a powerful technique for the determination of sizes and shapes of small
bodies in the solar system that can reach sub-km accuracy. Besides the main body, the
technique also allows the study of its surroundings, which can lead to the discovery and
characterization of rings, jets, and atmospheres at nanobar level, precisions only
comparable with in loco spacecraft. One interesting characteristic of a stellar occultation is
that the brightness of the star is more important than the occulting object since it is observed
its flux (brightness) variation when the object passes in front of it for a short period of time. A
crucial process for the success of this technique is event prediction, which is expected to
have an unprecedented increase as soon as LSST starts to operate due to tenths of
thousands of new objects being discovered combined with Gaia astrometry. As the number
of predictions increases, a higher number of observations is also expected, as well as the
amount of data. In this context, the python library SORA (Stellar Occultation Reduction and
Analysis) was developed to help with the analysis of stellar occultation light curves. Here we
present the first steps in the development of a graphical interface that uses SORA in order to
provide an easy and accessible tool for the professional and citizen scientists who
participate in stellar occultation observations. We will also present the latest version of the
interface which was developed together with a team of IT specialists.

Kilonovae with Rubin: From Alerts to Science
Tomas Ahumada

The joint detection of gravitational waves (GW) and electro-magnetic (EM) radiation coming from a binary neutron star merger allowed for the most detailed follow-up campaign in the history of astronomy, unveiling different physical processes as well as leaving many open questions.
Here, we explore the how the incoming Rubin Observatory will be able to serendipitously find the near infrared (NIR) / optical transient associated to these events, the kilonova (KN), independently from GW or short gamma-ray burst (SGRB) triggers. For this, we recreate the universe accessible to the survey and use it to derive contamination rates for different classes of transients. When using a filtering scheme based on the magnitude evolution of the sources, we find that ~90% of the sources that fade faster than 0.4 mag/day are either GRB afterglows or supernova (SN) type IIb shock breakout. This strategy is only capable of retrieving ~3% of the generated KNe, mainly due to the fast-fading nature of the KNe and their intrinsic low luminosity. We propose that future filtering schemes should take into consideration not just the detections, but the magnitude difference between the last detection and the subsequent. Additional information as color, host galaxy or NIR counterparts on future NIR surveys should also be incorporated.

The Effect of Vera C. Rubin Observatory Filter and Return Time Selections on Kilonova Detectability

Raiyah Alserkal, Cristina Andrade, Luis Salazar-Manzano, Igor Andreoni, Michael W. Coughlin, Nidhal Guessoum, Liliana Rivera Sandoval

Binary neutron-star mergers are notable astrophysical phenomena; they offer us an opportunity to examine various processes, including astrophysical heavy-element nucleosynthesis, merger- driven mass ejections, wide spectrum electromagnetic emissions, and now gravitational waves. The discovery of the optical/infra-red counterpart to the neutron binary merger gravitational wave
detection (GW170817), which followed a short gamma-ray burst (GRB170817), was a groundbreaking moment in multi-messenger astronomy. It is, to date, the only confirmed joint detection of its kind, though many projects are currently developing wide-field surveys to find more electromagnetic counterparts, known as kilonovae, or fast-fading afterglows. The improvement of kilonova detection methods from varied samples of sources is a rather difficult task because kilonovae are faint and fast fading. Fortunately, the Vera C. Rubin Observatory provides excellent prospects for identifying kilonova candidates either from, or independent of, gravitational-wave and gamma-ray burst triggers. Its 10-year project called the Legacy Survey of Space and Time (LSST) will conduct surveys of an exceptional volume of the sky in 6 photometric filters. Indeed, LSST has the potential to open the world of fast transient science at excellent depth. Cadence choices for LSST surveys are especially important for maximising detections. In this work, we explore

the possibility of optimising Rubin Observatory’s ability to detect kilonovae to by studying both existing LSST cadences and ones provided by the project, subsequently studying how detection rates are affected by filter selections, notably red/IR filters (i, z, y) compared to bluer filters (u, g, r), the return timescales for visits of the same area in the sky, and other relevant factors. We assess the benefit of our findings to related scientific interests, including maximising a range of fast transient discoveries.

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#7

Thanks @rstreet - so tomorrow? Month missing in date.

#8

Sorry for the ambiguity, and thanks for pointing it out @aprajita !
Yes, this colloquium will be tomorrow.

#9

The recording of today’s colloquium can be found here.

#10

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Kickstarter Science Colloquium

Our next Kickstarter Science Colloquium will feature:

Building a Diverse Generation of Rubin Scientists: a pilot program

By Antonino Cucchiara

Binary Neutron Star Mergers: Detectability with Vera C. Rubin Observatory
By Luis Salazar-Manzano,

Liliana Rivera Sandoval w/ Michael Coughlin, Igor Andreoni, Cristina Andrade, Raiyah AlSerkal, Ritwik Sharma.

RR Lyrae in Local Group Dwarf Galaxies
By Kenneth Carrell,

Yoojin Choi, Vittorio Braga, Massimo Dall’Ora, and Marcella Di Criscienzo

Monday Oct 17, 2022
22:00 - 23:00 UTC
3 - 4pm PDT
6 - 7pm EDT
Midnight - 1am CEST
11am - noon + 1day NZTZ

Meeting link: https://us02web.zoom.us/j/84484780466?pwd=U0dvQ2dDOCtoRk5sbnd1T05IREVHQT09

Building a Diverse Generation of Rubin Scientists: a pilot program

By Antonino Cucchiara

Create an inclusive and thriving environment that will include researchers from different

career stages and institutions is going to be a key component of the Rubin ecosystem.

It is important to recognize the importance of being inclusive from the science collaborations composition to the leadership overall.

To facilitate the access to Rubin science goals, LSST structure and resources, we designed a new pilot program that focuses on the mentoring of faculty-student pairs (FSP) selected from institutions traditionally marginalized both in the US and Worldwide.

Four FSPs were selected and mentored by Rubin researchers that have common scientific interests. FSP were provided also opportunity to build knowledge and skills that will allow them to continue to be engaged with the Rubin community after the award period and to self-sustain their research endeavor through competitive funding sources.

In this talk I will present the results of this pilot, including lessons learned and recommendations

if this model will be adopted by Rubin in the future.

Binary Neutron Star Mergers: Detectability with Vera C. Rubin Observatory
Luis Salazar-Manzano

The discovery of the optical/infra-red counterpart AT2017gfo (a Kilonova, KN) of the neutron binary merger gravitational wave detection GW170817 was a groundbreaking moment in astrophysics. Our capacity to achieve a proper understanding of KNe and the branches of astrophysics benefited from them, depends on detecting and characterizing a large sample of sources. The volume that the Vera C. Rubin Observatory will probe makes this observatory a powerful tool to detect KNe independent of any gravitational wave or GRB trigger. In this work we assess KNe detectability in the most recent v2.0 and v2.1 simulations of the LSST survey strategies.

RR Lyrae in Local Group Dwarf Galaxies
Kenneth Carrell,

Yoojin Choi, Vittorio Braga, Massimo Dall’Ora, and Marcella Di Criscienzo

The LSST will revisit locations on the sky multiple times over the planned 10-year survey, making it an excellent dataset for studying transient phenomena, and variable stars in particular. The most important factor for characterizing transient objects is the number of visits to that particular target (the cadence of observations could also affect objects with specific frequencies), and in general, the number of visits to a set of sky coordinates is both time and filter dependent. As an initial test of one of the baseline strategies, we have run a set of simulations observing theoretical RR Lyrae models in dwarf galaxies in the Local Group for different data releases. We will present how well lightcurve properties, such as mean magnitude and amplitude, can be recovered for different types of RR Lyrae, lengths of survey time, and distances to the dwarf galaxies.

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Kickstarter Science Colloquium

Our next Kickstarter Science Colloquium will feature:

Counts, Colors, Kinematics and Ages for Ultracool Dwarfs with HST surveys and the Vera Rubin Observatory

By Christian Aganze

Monday Nov 14, 2022

16:00 - 17:00 UTC
8 - 9am PST
11am-noon EST
5 - 6pm CET
5 - 6am + 1day NZTZ

Meeting link: https://us02web.zoom.us/j/89813160226?pwd=RlVsSlFrdThiZmZ1bHk5cTg2N0g4QT09

Counts, Colors, Kinematics and Ages for Ultracool Dwarfs with HST surveys and the Vera Rubin Observatory

By Christian Aganze

Ultracool dwarfs stars and brown dwarfs (M< 0.1 solar masses) comprise a significant proportion of stars in the Milky Way. Deep samples of ultracool dwarfs have the potential to constrain the formation history and evolution of low-mass objects in the Galaxy, but well-characterized photometric and spectral samples have until recently been limited to the local volume (d < 500 pc). Deep imaging and spectroscopic surveys provide an opportunity to find distant brown dwarfs out to >1 kpc. I will present my work on finding distant ultracool dwarfs in two HST/WFC3 parallel surveys, WISPS & 3D-HST. I will demonstrate how machine learning techniques provide a better selection compared to traditional index-based methods in deep spectroscopic samples, and I will present a sample of 164 late-M, L, and T dwarfs extending to 2 kpc. The next generation of deep and wide-field surveys conducted, including the Nancy Grace Roman Telescope, and the Vera Rubin Observatory will uncover millions of UCDs throughout various environments in the Galaxy, and new tools are needed to analyze these data. I will also present a python-based Monte-Carlo population simulation tool designed to model UCD populations throughout the Milky Way. By varying parameters such as the stellar mass function, star formation history, UCD evolutionary models, galactic structure, mapping between physical and observable properties for different populations, and survey properties and selection functions, I can predict the expected number counts and distributions of spectral type, color, and kinematics of UCDs in various surveys, as well as analyze the population properties of UCDs from the large samples expected from these surveys. I use this tool to simulate expected counts and colors of UCDs as observed by the Vera Rubin observatory. Rubin will detect ~1 million UCDs, including > 300,000 L type dwarfs and thousands of T dwarfs with full photometric information in g, r, i, z and y bands, and precision astrometric measurements. This population will be dominated by thick disk and thin disk sources, with >10,000 halo late-Ms and early L dwarfs.

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Kickstarter Science Colloquium

Our next Kickstarter Science Colloquium will feature:

Young stellar objects and their variability with Rubin LSST: combining observations and 3D models for a more inclusive Science

By Laura Venuti and Sabina Ustamujic

Wednesday Nov 16, 2022

17:00 - 18:00 UTC
9 - 10am PST
noon-1pm EST
56- 7pm CET
6-7am + 1day NZTZ

Meeting link: https://us02web.zoom.us/j/86170038484?pwd=bzlUelIycnFHaDMzaGQxY2QvK1hPUT09

Abstract
Photometric variability is a defining feature of young stellar objects (YSOs), with characteristic signatures across the wavelength spectrum, and presumed origin in a combination of starspots, disk accretion, and circumstellar obscuration effects. Prominent flux changes are typically observed on baselines of hours to weeks, which mirror the dynamical timescales of the inner disk. For some YSOs, known as eruptive variables, more intense flux variations have been identified on timescales of years to decades. However, the non-uniformity of earlier campaigns has so far hindered the possibility of achieving a statistical view of how the photometric behaviors of young stars evolve across the time domain. Furthermore, the sparsity of coordinated multi-wavelength observations of YSO variability, crucial to reconstruct the spectrum of the emitting region, has prevented a systematic classification of the corresponding, main physical drivers behind the observed flux behaviors. In this project, we aim to investigate the variability in YSOs at different time scales. To this end, we are pursuing two main activities: 1) analyzing YSO light curves from public datasets of young star-forming regions from available large-scale surveys in preparation for Rubin LSST data; 2) developing models and 3D renderings reproducing the geometry of star-disk systems that could explain the variability observed in the data and that would give rise to specific light curve patterns. Our final goal is to create a catalogue of publicly available interactive 3D graphics and 3D printed kits to adequately present Rubin/TVS science to visually impaired researchers and members of the community at large. Here we present our preliminary results.

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#13

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Kickstarter Science Colloquium

On Thursday, we will hold a Kickstarter Science Colloquium featuring:

** A Survey Simulator for Solar System Science with the LSST**

By Steph Merritt and Grigori Fedorets

Thursday Nov 17, 2022

17:00 - 18:00 UTC
9 - 10am PST
noon-1pm EST
56- 7pm CET
6-7am + 1day NZTZ

Meeting link: https://us02web.zoom.us/j/84633241924?pwd=UjUwUHJkc1NmVmlrOHg4Ykd3akFQdz09

Abstract
Over its 10 year lifespan, LSST could discover over 5 million main belt asteroids, 300,000 Jupiter trojans, 100,000 near-Earth objects, and over 40,000 trans-Neptunian objects, providing an unprecedented opportunity for population studies of small bodies within our Solar System. However, like all surveys, these discoveries will be affected by observational biases, obscuring the properties of the true underlying populations. Survey simulators have already proven to be a powerful tool in Solar System surveys: by replicating and applying the known observational biases of a survey to a population of synthetic objects, simulated forward-biased distributions can be compared directly to real detections. For this purpose, we present surveySimPP, an open-source survey simulator post-processing layer designed to replicate the observational biases of the LSST and the behaviour of the Rubin Observatory Solar System Processing pipeline. Designed to be easy-to-use, highly modular and to run in both desktop and supercomputer environments, we describe how surveySimPP models the complex observational biases of the LSST and present a number of predicted science use-cases, demonstrating the power and necessity of this survey simulator for accurate characterisation of Solar System small-body populations. The code is presently used by the Rubin Solar System Pipelines team for science projections and pipeline verification.

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#14

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Kickstarter Science Colloquium

On Thursday, we will hold a Kickstarter Science Colloquium featuring:

Characterization of tidal debris around the bulge Globular Clusters NGC 6569, BH 261 and Patchick 99

By Andrea Kunder, Joanne Hughes, Kristen Larson, Katie Devine

Thursday Dec 1, 2022

23:00 - 00:00 UTC
3 - 4pm PST
6-7pm EST
midnight - 1am CET
noon - 1pm + 1day NZTZ

Meeting link: https://us02web.zoom.us/j/85225969518?pwd=OG1UOU02cWlaTmFRYXlsMWIzZXZMdz09

Abstract
What proportion of the stellar population in the bulge of the Milky Way has been stripped from globular clusters? We are using Gaia astrometry and the Blanco DECam Bulge Survey (BDBS) catalog — a precursor survey to LSST — to search for candidate extra-tidal stars around 20 inner Galaxy globular clusters. Here a spectroscopic analysis of stars in and around three bulge clusters, NGC 6569, BH 261 and Patchick 99, is presented from spectra collected using AAOmega@AAT. We report on the discovery of extra-tidal (up to 5 tidal radii) stars around NGC 6569 and BH 261. Metallicities from the Calcium triplet are also in agreement with these stars being more metal-poor than the surrounding bulge field stars. Theoretical modeling show both NGC 6569’s and BH 261’s tidal tails could be complex, due to dynamical stirring by the Galactic bulge. Our spectroscopic follow-up observations of the candidate cluster Patchick 99’s stellar population show no clumping in radial velocity space consistent with a globular cluster. However, three RR Lyrae stars within 10 arcmin of the “cluster” center have similar radial velocities and proper motions, suggesting these may have a common origin. If Patchick 99 is indeed a bonafide globular cluster, the large spread in both proper motion and radial velocity, the paucity of stars populating a giant branch, as well as its similarity to the field, would suggest Patchick 99 is dissolving in the bulge and was part of a larger system in the past.

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#15

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Kickstarter Science Colloquium

On Mon Dec 5, we will hold a Kickstarter Science Colloquium featuring:

Solar System Small Body Dynamical Characterization in the LSST Era
By Kat Volk

and

PulsationStarRecovery metric for LSST data
By Vittorio Braga

Monday, Dec 5, 2022

16:00 -17:00 UTC
8am - 9am PST
11am - noon EST
17:00-18:00 CET
05:00-06:00 + 1day NZTZ

Meeting link: https://us02web.zoom.us/j/84720028145?pwd=c1V2UFVKYi8vZzRtUTZMenc0QmQzUT09

Solar System Small Body Dynamical Characterization in the LSST Era
By Kat Volk

Dynamical analyses of the solar system’s small body populations have led to many important insights in planetary science. The dynamical evolution of an observed small body’s orbit can place it into context as, for example, a primordial small body that has remained largely unchanged since formation (like the New Horizons target Arrokoth in the Kuiper belt) or as an object that was captured into a mean motion resonance with a planet during the epoch of giant planet migration; both kinds of objects are critical for testing models of the solar system’s early dynamical history. In the past, the number of small bodies discovered in any new solar system survey has been small enough (~1000 objects) that dynamical analyses could be done in a human-intensive way (such as via visual inspection of numerical integration outputs). Given that LSST is expected to discover millions of main belt asteroids and tens of thousands of new transneptunian objects (amongst other small body populations!), we need a more robust approach to automated dynamical characterization! We used our LSST kickstarter funds to start developing a now NASA-funded open-source, user-friendly Python package that can take a small body orbit, perform dynamical integrations of its orbital evolution, calculate a variety of dynamical parameters, and output dynamical characterizations and classifications. I will briefly review the key dynamical parameters that are of most value for small body science, then show how machine learning can be a powerful tool for converting relatively simple, well-chosen time-series analysis of orbital integration results into robust dynamical classifications in the outer solar system.

PulsationStarRecovery metric for LSST data
By Vittorio Braga

Pulsating variable stars are precise standard candles and stellar population tracers. LSST will deliver ugrizy time series down to r~25, over a wide sky area, allowing to constrain their distance diagnostics with unprecedented precision. I will describe a new tool called PulsationStarRecovery, designed to quantify the recovery of the light curve period and amplitude from a Rubin LSST simulated time series. The metric takes, as input, synthetic light curves of Cepheids, RR Lyrae and Long-Period Variables from pulsation models, and gives as outputs the estimated pulsation properties (period, mean magnitude, pulsation amplitude…). PulsationStarRecovery is included within the MAF and its main purpose is to check how well the pulsation properties are recovered, depending on the observation strategy adopted, distance, coordinates, time of observation. I will show the results of a few tests for some realistic science cases, focussing on the Local Group galaxies.

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Kickstarter Science Colloquium

On Tuesday Dec 6, we will hold a Kickstarter Science Colloquium featuring:

Discovering Stellar Systems in and around the Milky Way with LSST data
By Adriano Pieres, Ana Clara de Paula Moreira, Raslan Oliveira Ribeiro, Rocío Milagros

and

The impact of LSST cadence on eclipsing binary science

By Andrej Prsa

Tuesday, Dec 6, 2022
17:00 UTC
9am PST
Noon EST
18:00 CET
06:00 NZTZ + 1day

Meeting link: https://us02web.zoom.us/j/85265611985?pwd=T1ZMTXNsekhldjBYd1FmY09uYWprQT09

Discovering Stellar Systems in and around the Milky Way with LSST data
By Adriano Pieres, Ana Clara de Paula Moreira, Raslan Oliveira Ribeiro, Rocío Milagros

We present the Gawa (Galactic Archeology star cluster finder using Wavelet maps) project to detect faint halo clusters and dwarf galaxies around the Milky Way using LSST data. We will discuss the challenges we have faced along the project, the code of simulations and detections, and its results up to date, along with the work done funded by Heising-Simons Foundation and perspectives in the nearby future.

The impact of LSST cadence on eclipsing binary science

By Andrej Prsa

The Legacy Survey of Space and Time is slated to commence in 2024 at the Vera Rubin Observatory. One of the crucial parts of preparing the survey is the choice of observing cadence in an effort to optimize auxiliary science goals while maintaining the core project requirements. Here we look at the impact of proposed cadences, encoded in different operations simulation runs (opsims), on non-time-critical eclipsing binary science. This is particularly pertinent because LSST is the first large-scale survey that will provide us with color information in addition to high precision coverage of faint targets. We study the differences between the baseline opsim v2.1 and the 4 draft opsim v2.99 runs. We find that all 5 runs provide sufficient data quality to enable in-depth studies in the field of eclipsing binaries, and that there are no adverse impacts from any opsim modification studied here.

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#17

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Kickstarter Science Colloquium

On Thursday Dec 8, we will hold a Kickstarter Science Colloquium featuring:

Making it easier to install, use, validate, and compare orbit-fitting software packages

By Sarah Greenstreet, Joachim Moeyens, Aidan Berres, Aditi Chauhan

Thursday Dec 8, 2022

23:00 UTC

3pm PST

6pm EST

Midnight CET

Noon +1day NZTZ

Meeting Link: https://us06web.zoom.us/j/85327089623?pwd=M0JoZTEzRWZPQVJheTAzWHVSOERkQT09

Making it easier to install, use, validate, and compare orbit-fitting software packages

A number of software packages are widely used across the Solar System science community to fit orbits to observations of moving objects, propagate orbits, generate ephemerides, or perform long-term numerical simulations of moving object populations. These orbit-fitting and integration codes are vital to the discovery and tracking of small bodies and the study of their histories and evolutions. However, many of these software packages only have available out-dated or non-existent documentation, unintuitive installation processes, and/or little information about required default and configuration settings. This makes getting started with these packages difficult, at best, for those without the necessary experience or knowledge available to them. Additionally, few, if any, of these software packages provide end-to-end tests of their orbit determination calculations that can allow users to verify and validate their results. This can create uncertainty in the integrity of fitted orbits, potentially leading to the loss of newly-discovered moving objects. Each of these orbit-fitting codes also use slightly different methods for orbit computation, which often results in varied performance between the codes for objects in different dynamical classes, e.g., near-Earth objects, main-belt asteroids, and transneptunian objects. In order to improve the installation processes, set-up documentation, validation, and comparison of the three orbit-fitting software packages most commonly-used across the Solar System science community (Find_Orb, OpenOrb, & OrbFit), we have conducted two projects, including the development of a software package called “Orb_It”. We will describe Orb_It’s capabilities to validate and compare the results of these three orbit-fitting codes. In addition, we will discuss our work to make it easier to install and use these codes. Together, this work is helping to lower entry barriers for those wanting to get involved in the LSST Solar System Science Collaboration and prepare for doing science with LSST in addition to benefiting the broader community.

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#18

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Kickstarter Colloquium

Our next Kickstarter Colloquium will feature:

Spectroscopic target prioritisation with AAS2RTO: Automated Alert Stream to Real Time Observation Algorithm
By Aidan Sedgewick

and

Probabilistic estimation of photometric redshifts
By Jacob Osman Hjortlund

Monday, Dec 12, 2022

16:00 UTC
8am PST
11am EST
17:00 CET
05:00 + 1day NZTZ

Meeting link: https://us06web.zoom.us/j/81180933264?pwd=MDNMMDA5aVhjcWtGTDJtSy8yS0NUZz09
Spectroscopic target prioritisation with AAS2RTO: Automated Alert Stream to Real Time Observation Algorithm
By Aidan Sedgewick

Dedicated rapid follow-up spectroscopic observations of transient events in real time in response to the alert stream from the Rubin Legacy Survey of Space and Time (LSST) alert brokers will be a rare resource. The Danish-1.54m telescope on La Silla, Chile, may offer such an opportunity: with the aim of becoming a (semi-)robotic facility, it will be used (in part) to follow up selected targets using the recomissioned DFOSC spectrograph. Based primarily on the alerts and filters provided by the FINK broker, we will present our initial investigations into developing a software package to automate building a ranked target list. Our code listens for alerts and ranks targets based on intrinsic target properties (brightness and colour), alert classification confidence, and properties of the observing site.

Probabilistic estimation of photometric redshifts
By Jacob Osman Hjortlund

Photometric redshifts (photo-z’s) are challenging to determine at high enough quality for use in cosmological applications. Modern machine learning (ML) methods can provide extremely fast estimates of, say, redshifts by learning complex mathematical dependencies from photometric data, but they typically rely on access to a high-quality, “fully-labeled” (i.e., each photometric object has an associated spectroscopically determined redshift) dataset where each datum is known exactly. Such a scenario is a poor fit to astronomical surveys, where photometric quantities are typically associated with uncertainties, and only a small subset of the photometric objects have had follow-up spectroscopic observations made to determine their redshifts. Furthermore, most ML methods provide point-estimates for the quantities they predict, e.g., photo-z’s. However, uncertainty estimates, preferentially as small as possible, on any measured redshifts are essential in distance determinations used for cosmology. Even for ML methods that can provide uncertainties, the estimates are not yet at a level that satisfy cosmological needs. In this project we attempt to address these issues by using 3 different semi-supervised ML models for probabilistic estimation, the prediction of photo-z distributions. This colloquium will focus on current overall progress in the project as well as preliminary results for 1 of the 3 implemented models on a combination of SDSS and WISE data.

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#19

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Kickstarter Colloquium

Our next Kickstarter Colloquium will feature:

The Blanco DECam Bulge Survey: A Rubin Crowded field Pathfinder project on DECam
By R. Michael Rich

and

Stellar variability with Rubin-LSST
By Matteo Monelli

Wednesday, Dec 14, 2022
17:00 UTC
9am PST
Noon EST
6pm CET
6am + 1day NZTZ

Meeting Link: Launch Meeting - Zoom

The Blanco DECam Bulge Survey: A Rubin Crowded field Pathfinder project on DECam
By R. Michael Rich

Abstract: We have surveyed 200 sq. deg. of the most crowded Southern Galactic bulge regions using DECam on the Blanco 4m telescope. This instrument has many of the characteristics of the Rubin Observatory. We have produced color-magnitude diagrams for the field and 27 globular clusters. We have also calibrated (u-i)_0 vs [Fe/H] resulting in photometric metallicities for 3 million red clump giant stars in the bulge. We find dramatic changes in the metal abundance from -4 deg to -10 deg galactic latitude, in which two very different abundance distribution functions are expressed; there are implications for chemical evolution of the bulge. We also find new constraints on young and intermediate age populations in the bulge, and explore correlations between abundances and kinematics in the bulge. We discuss our ongoing efforts to achieve high quality crowded field reductions using the LSST pipeline, tests we plan to use to check convergence, and the prospect for exciting Galactic science from the LSST surveys.

Stellar variability with Rubin-LSST
By Matteo Monelli

I will present the results obtained within the framework of our kickstarter program.
In particular, I will present time series data of one DECam field in the Galactic disc. I will discuss the search and analysis of variable sources: we identified a large number of binary stars, few RR Lyrae stars, and also a number ofnon-periodic sources still unclassified. Different algorithms for period funding were tested.

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#20

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Kickstarter Colloquium

Our next Kickstarter Colloquium will feature:

The Transients and Variable Stars Science Collaboration Roadmap Outlined
By Kelly Hambleton

and

The Impact of Satellite Constellations on Solar System Science with LSST
By Siegfried Eggl

and

Regional storage support for LSST related science
By Saša Simić

Monday, Jan 16, 2023
17:00 UTC
9am PST
Noon EST
6pm CET
6am + 1day NZTZ

Meeting Link: https://us06web.zoom.us/j/89250507749?pwd=OWZjZUNWeTQwR1RoM2JadDhocEhTZz09

The Transients and Variable Stars Science Collaboration Roadmap Outlined
By Kelly Hambleton

The Transients and Variable Stars Science Collaboration (TVS SC) is one of eight Rubin LSST Science
Collaborations. The purpose of the TVS SC is to ”Explore the transient sky”, one of the four primary
objectives of Rubin LSST. As ”Transients and Variable Stars” covers a wide range of science fields, the
TVS SC is one of the largest and most diverse of all the Rubin LSST Science Collaborations. This is
reflected in their roadmap, which contains contributions from over 50 TVS SC members, detailing their
proposed research areas including periodic and non-periodic variable events; explosive and eruptive
transients; and geometric transients. The Roadmap is divided into three main parts, which cover
the Main Survey, Mini Surveys and Deep Drilling Fields. The Main Survey is further divided into
time-critical and non-time-critical science, where time-critical science depends on Broker Alerts (i.e.
Supernovae) and non-time critical does not (i.e. pulsating stars). During this talk, we discuss the TVS
Roadmap and highlight some of the exciting new science cases that will be tackled with Rubin LSST
data.

The Impact of Satellite Constellations on Solar System Science with LSST
By Siegfried Eggl

Constellations of tens of thousands of artificial satellites in low Earth orbit pose new challenges to ground based Astronomy. While previous satellite designs were bright enough to cause data-loss on detectors through saturation and CCD cross talk, some of the recently launched satellites reach apparent magnitudes around V~1mag. If not actively avoided, such satellites could potentially damage detectors of the next generation of ground based telescopes such as the upcoming Vera C. Rubin Observatory’s. In this contribution we present results of the LSSTC Kickstarter Program 2022 on the effective data loss caused by constellations of artificial satellites for Solar System Science with the Legacy Survey of Space and Time (LSST) if no mitigation strategies were employed. Preliminary results suggest that several percent of the LSST discovery Solar System object discovery yield could be lost due to the interference of fully deployed constellations of artificial satellites in Low Earth Orbit (LEO).

Regional storage support for LSST related science
By Saša Simić

With this project, we bring together two LSST in-kind teams from Serbia and Croatia with the goal of joining their efforts and expanding their research capacities in the areas of data storage, processing, and administration for LSST-related science. We anticipate a requirement for an important component - data storage - as part of the proposed collaboration. Both teams will generate a substantial amount of data as a result of their LSST in-kind contributions, i.e. the intermediate and final data products of LSST-related work. As a result, we suggested here the acquisition and installation of cloud data storage (CDS) at the University of Kragujevac in Serbia. The primary goals of this project are to develop the region’s first open-access storage system for LSST-related science, to establish long-term collaboration between the Serbian and Croatian LSST in-kind teams, and to expand astronomical research capacity at the University of Kragujevac. In this presentation we give a detailed description of CDS services access and established capabilities.

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