Exoplanets: some contributions
What is expected from Gaia?
In 2000, and as part of the scientific case for Gaia, I made the first estimates of the number of giant exoplanets that the satellite should discover through the positional 'wobble' of the host star, and putting the number at somewhere between 10,000 - 50,000, depending on details of their orbital distribution. Several refinements of these estimates have been made since. My study in 2014 predicted the number of astrometric discoveries at around 20,000 for a 5-year mission duration, and perhaps up to 70,000 for a 10-year mission. Others have also estimated the additional numbers of discoveries expected from Gaia's photometric data, through the detection of their photometric transits.
As of mid-2021, the Gaia satellite has acquired around seven years of data. It may continue to operate until around 2023. It is an enormous number-crunching problem, currently ongoing, to process the vast amounts of data coming from the satellite. Any exoplanet discoveries (including the 'final' discovery numbers) can only be announced towards the very end of the processing chain. If some reasonably secure results will be available by around 2025, it will have been a quarter century between my first experimental predictions, and the actual discoveries. I'm sure it will be worth the wait!
The Exoplanet Handbook
Soon after the discovery of the first exoplanets in 1995, I looked at whether the reflex motion of the host stars of the first three discoveries was seen in the Hipparcos data (it wasn't). But this research paper led to an invitation to review the embryonic field of exoplanet science, which was published in the journal Reports on Progress in Physics in 2000. This later developed into my book-length review of the field published by Cambridge University Press in 2011, with a second edition in 2018.
The 'Perryman Tree'
I created this diagram for my review in 2000, and have updated it regularly since (mostly as of 1 January each year). It shows the total number of exoplanets known at the time, sub-divided according to discovery method.
This gallery has the latest version, 1 January 2024, and some earlier versions, giving an idea of how the field is developing with time. These gallery images (navigate with > or < button) are all jpg format. A vector pdf of the latest version is available here.
Status as of 1 January 2024
Status as of 1 January 2022
Status as of mid-2000
Status as of 1 January 2024
Exoplanet Handbook (second edition 2018): Appendixes and Updates
The following files are available at the Cambridge University Press www site (under Resources/Appendixes) and included here also.
ExoplanetHandbook2-AppendixC-F-end2017.pdf
contains the four Appendixes C-F, which together provide a compilation of the exoplanets discovered by the stated method (radial velocity, transits, lensing and imaging respectively), and largely following the content of the NASA Exoplanet Archive as of the end of 2017 (and corresponding to 3572 known exoplanets in total). Other discoveries, notably by timing methods and astrometry, are listed in the relevant chapters of the main text. This version corresponds to the published edition, viz. listing the known planets as of the end of 2017, and the main bibliography (according to the literature survey by the author) also as of the end of 2017. In order to maintain full congruence with the published edition, the References included in this pdf version correspond to the complete bibliography for the published edition (and not only to the content of the Appendixes). Since this version has been superseded, it will be of little or no interest to most users.
ExoplanetHandbook2-AppendixC-F-end2018.pdf
contains the four Appendixes C-F, with system and planet content updated to the end of 2018 (according to the NASA Exoplanet Archive, and corresponding to 3869 known exoplanets in total). The bibliography has been correspondingly updated for all systems. Since this version has been superseded, it will be of little or no interest to most users.
ExoplanetHandbook2-AppendixC-F-end2019.pdf
contains the four Appendixes C-F, with system and planet content updated to the end of 2019 (according to the NASA Exoplanet Archive, and corresponding to 4104 known exoplanets in total). The bibliography has been correspondingly updated for all systems.
Exoplanets included: Content corresponds essentially to that of the NASA Exoplanet Archive at the given dates. Some additional systems of note are also included. Primary identifiers correspond to those given in the NASA Exoplanet Archive.
Bibliography included: The bibliography provides a concise overview and narrative of the currently perceived importance and scientific developments associated with each system. Ordering is by year, and then by first author. Bibliographic entries are a result of my own literature survey, and claim no completeness: the CDS SIMBAD facility can be consulted for a more extensive bibliography for each system. For the version updated to the end of 2018, and because of the many new references included, the reference keys are not (necessarily) congruent with those given in the published Second Edition.
Hyperlinks: These pdf versions are extensively hyperlinked as follows:
* host star names (bold) are hyperlinked to the relevant NASA Exoplanet Archive 'Planet Host Overview' page
* citations are hyperlinked to the relevant page of the References
* each small triangular symbol following the citation is hyperlinked to the associated SAO/NASA ADS Abstract page