July 22, 2022 - version 3.2 released
This release is accompanied with a dedicated paper describing all details. This paper can be accessed now from A&A as the forthcoming paper and from: http://arxiv.org/abs/2206.11047 (both are free access sources).
In short:
this is a major update accounting for new stellar data found in the Gaia EDR3 catalogue. In this release we decided to temporary limit the list of stars and stellar systems to those that nominally pass the Sun closer than 2 pc. As a result, we composed a new list of 155 potential stellar perturbers of the long-period comet motion. This list consists of 142 stars (including seven binaries) from the previous list updated with the data from Gaia EDR3 and 11 new single stars and two binaries added on the basis of the new Gaia EDR3 data. For each object, we also estimated the uncertainty of the parameters of their closest approach to the Sun. Among these stars, we found a new potentially strong past perturber, HD 7977, and confirmed the plausibility of a similar action on the part of Gliese 710 in the future.
In comparison with the StePPeD release 2.3, several important changes in the list of the closest stellar encounters to the Sun have appeared. What is probably the most important is the complete removal of the perturber P1079 (ALS 9243), discussed in detail in a paper: A surprise in the updated list of stellar perturbers of long period comets motion by Rita Wysoczańska, Piotr A. Dybczyński, and Magdalena Polińska (2020). Its parallax changed from 10.5617±0.4027 to 0.16891±0.19025 mas, which moved this star to a large distance, additionally with a high uncertainty. The closest star- Sun approach of P0505 ( Gaia DR2 955098506408767360) in the past is also cancelled due to the parallax change from 34.5051±0.6146 to 1.53497±0.02945 mas. These two stars were the most important perturbers in the StePPeD release 2.3 from the point of view of a dynamical evolution of LPCs, based on the Gaia DR2 results.
An access to the previous release (3.1) is available here. Beware that version 3.1 will not be maintained in the future.
November 21, 2021 - version 3.1 released
This is a minor revision containing new radial velocities for a handful of stars and a correction of a typo in the Scholz's star (P0403) mass.
According to the data from Table 2 found in the paper: 2020PASP..132f4504E we have updated radial velocities for: P0230, P0305, P0312, P0509, P0508, P0505, P0510, and P0515.
According to the paper: 2021A&A...652A..45L we have also changed the radial velocity of P0005.
All calculations were repeated, new stellar and solar ephemerides were produced.
September 15, 2021 - version 3.0 released
This is the first part of the total update to incorporate Gaia EDR3 results. At this stage no new star were added but all stars from the version 2.3 were checked against EDR3 astrometry, new input data files were prepared and all results were recalculated. In cross-identifications we added Gaia EDR3 numbers and identifications from the Washington Double Star Catalogue where available. A lot of refinements were applied, especially for multiples.
There is a new set of files in the download section: stellar ephemerides. A paper describing this in detail is here (preprint on arXiv).
The work is in progress and the second part of the update, namely adding new stars from Gaia EDR3 will happen soon. At the second part we will also add some new features, including Monte Carlo estimates of the Sun - star encounter uncertainties and a graphical presentation of some results. A paper describing the details of the update process is in preparation.
An access to the previous release (2.3) is available here. Beware that version 2.3 will not be maintained in the future.
September 25, 2020 - this database has been named!
On the user request and to simplify the usage and quoting we decided to name our database. From now on it will be named: StePPeD. This do not change the version number, it is still 2.3
July 27, 2020 - version 2.3 released as a result of adding 6 new stars.
As a result of analyzing two papers:
- Bobylev & Bajkova, 2020 ( bibcode: 2020arXiv200616555B )
- R. Darma et al 2019 J. Phys.: Conf. Ser. 1245 012028
we added six new stars to our database. These are:
Gaia DR2 3130033734235815424 as P0036
Gaia DR2 969867803725057920 as P0442
Gaia DR2 365942724131566208 as P0753
Gaia DR2 3863292438160881792 as P0754
Gaia DR2 3106503768787702528 as P0755
Gaia DR2 3423180542272114688 as P0756
Our database now consists of 825 potential perturbers i.e. 787 single stars and 38 multiple systems. Among them 648 objects might pass the Sun closer than 4 pc. All relevant results were recalculated and files available for download were updated.
July 20, 2020 - small upgrades of the database interface.
Added were lists of our objects by their identifiers in various catalogues. Several small interface errors were corrected.
May 2, 2020 - two objects merged into one multiple perturber, version 2.2
During several careful checks we found that objects P0209 and P0442 are components of the double system WDS J07002+4259. As a result we renamed these objects as P0209-A and P0209-B respectively and redefined the perturber P0209 as a double star object. Object P0442 has been deleted. All tables and results have been updated accordingly. Now we have 819 perturbers in our database and 642 of them can nominally approach the Sun closer that 4 pc.
April 17, 2020 - additional download, version 2.1
On the user request we added the third file available for download: a complete dump of all input data for all 852 singular objects in the database, i.e. positions, proper motions, radial velocities, parallaxes as well as the mass and heliocentric distance estimations. For all values both uncertainties (where available) and sources are also included. See our download section.
April 10, 2020 - release of version 2.0
- The main change is connected with the star distance calculation method. Instead of simply using an inverse of a parallax we decided to rely on the results of a paper: Estimating Distance from Parallaxes. IV. Distances to 1.33 Billion Stars in Gaia Data Release 2 by Bailer-Jones, C. A. L.; Rybizki, J.; Fouesneau, M.; Mantelet, G.; Andrae, R. (The Astronomical Journal, Volume 156, Issue 2, article id. 58, 11 pp., 2018).
- We have also changed all input data for an object P0403 (WISE J072003.20-084651.2) according to the latest paper devoted to it: WISE J072003.20-084651.2B is a Massive T Dwarf by Dupuy et al. (The Astronomical Journal, Volume 158, Issue 5, article id. 174, 14 pp., 2019)
March 5, 2020 - Initial release.
- This was accompanied with the release of the first version of an announcing paper: A surprise in the updated list of stellar perturbers of long period comets motion by Rita Wysoczańska, Piotr A. Dybczyński, and Magdalena Polińska.