IAU Div. A: Working Group on Astrometry by Small Ground-Based Telescopes

WORKING GROUP ON

ASTROMETRY BY SMALL GROUND-BASED TELESCOPES

News

We are grateful for the annual reports submitted. A new Working Group Annual Report for 2025 is available for reading.

Purpose of this Working Group

This Working Group on Astrometry by Small Ground Based Telescopes is a Working Group of the IAU Division A on Fundamental Astronomy.

It has been initiated during the XXVIth General Assembly of the IAU in Prague, in August 2006 by the Division 1 (Fundamental Astronomy) of the IAU. It has been extended by the division 1 or division A during the following general assemblies.

The goal of this WG is to update and maintain information on astrometric programmes and activities carried out by small telescopes (up to 2m diameter), to diffuse news through these pages and by e-mails, to facilitate the collaborations and to help for the coordination of the activities, when possible, in astrometry from ground-based telescopes.

These telescopes are generally easier to access than the larger ones and allow us to carry out observational programs on medium and long term. Thanks to these properties they are precious tools to contribute to the advance of our knowledge of the celestial bodies: many Solar System objects and some astrophysical objects. More generally, the small telescopes due to their number and their geographical spread, are very efficient for observation in network. This is a strength which is successfully applied for coordinated programs.

The intent of the Working Group is to help coordinate the existing programmes, to exchange information at an international level and to encourage participation in different projects in astrometry at large. Astrometric measurements of positions for dynamics, fundamental astronomy or astrophysics, but also photometric observations of events for determination of size and shape, determination of the parameters of rotation can pay benefit from these instruments. This is possible for example thanks to observations of mutual events of the natural satellites, stellar occultations, mutual events of binary asteroids, etc. Several such campaigns are encouraged.

Furthermore the role of the WG is also to teach the astrometry theory and practice to the next generation, this is why the organization of training stays are promoted.

Young Career Research in Astrometry

The Working Group members are looking for young career generation people willing to get to know what Astrometry is and which applications it has, to contribute in some ways to it by doing professional observations, making astrometric measurements, analysing your own and worldwide available astrometric results, developing various software tools, organising public events to outreach astrometric knowledge, etc. If you consider doing an Astrometric Bachelor-, Master-, or PhD-related project, we are glad to share our knowledge. If you are interested in going deeper into the world of Astrometry, please consider contacting the Working Group members in your country or us. As the emails are not directly available on the IAU website, we advise you to follow the institutional link cited on the IAU webpage of the person of your interest, and search for the contacts on the institution's webpage. Alternatively, you can contact us via a.ivantsov (at) oma.be and massaf (at) ov.ufrj.br .

Members

The Working Group operates mainly by e-mail. Follow this link for a list of the current Members of the Working Group. To the members: we kindly ask to check your profile information and introduce any updates on the IAU website, use the "Sign in" button in the right upper corner.

How to join the Working Group?
If you are interested in the WG activities and would like to contribute to them, we will be glad to get a message from you sent to a.ivantsov(_at_)oma.be and massaf(_at_)ov.ufrj.br.

Astrometric activities

Tools for the reduction: : We call your attention to the availability of the automatic PRAIA astrometric and photometric reduction tools (with free codes/User Guide/examples) to the world community since the end of 2023 :
- PRAIA webpage
- Praia papers' links for astrometry (or through ADS) and for photometry (or through ADS).
Collaboration in Astrometry: : On the best effort basis, we can propose assistance with the astrometric reduction of images already taken. Today there are plenty of small telescopes imaging the sky for various purposes. Our astrometry volunteers propose assistance with extracting accurate and high-accurate astrometry of almost all objects brighter than 3 sigmas over the background, so afterward you can share it with the scientific world. We are open to work with individuals and groups, please, drop a mail to both addresses: a.ivantsov(_at_)oma.be and massaf(_at_)ov.ufrj.br, and we will contact you as soon as possible.
Several follow-up: The work of the actual surveys and the advent of new large and fast surveys (e.g. Pan-Starrs, LSST,...) which store huge amounts of data, reinforce the need to have follow-up observations in particular for the study of the Near-Earth objects and the improvement of their orbits. Astrometry by small telescopes is very useful for this goal. For example:
- the Minor Planet Center posts a list of the NEOs which require to be observed. See also the MPC NEA Confirmation page.
- the ESA Near Earth Coordination Center web site gives also a list for close approaches and a risk list;
- the NEODys2 web gives another list.
- the NASA/JPL publishes a list of potentially hazardous asteroids that could be useful to observe.
- several NEOs follow-up programs are accessible through addresses published in this JPL page
Mutual event campaigns: photometry for astrometric purposes In 2024 we entered in a new mutual event season of the Galilean satellites of Jupiter and of the satellites of Saturn. Small telescopes can lead to astrometry of very high precision. Further details are available on the LTE-IMCCE page
Past astrometric activities: Numerous astrometric activities are performed with small telescopes. Here, we post a link to a list of the activities and, when possible, to some web pages from the teams themselves. A special mention will be made for activities which require a coordination of astrometric activities and which could use these pages in order to get in touch other teams.

Documents

In this section, we post a list of relevant documents and references related to astrometry by small ground-based telescopes. Don't hesitate to send such new references to the chairperson of this WG.

WORKING GROUP ON ASTROMETRY BY SMALL GROUND-BASED TELESCOPES