TEPCat: The Transiting Extrasolar Planet Catalogue
Jaymie Matthews
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe author proposes to document and describe the catalogue TEPCat, which compiles reliable information on transiting extrasolar planets available in the literature. The maintenance of such a database is helpful to the community.
The manuscript presents a good motivation, describes the catalogue and its classification criteria in detail, and presents some implementations of TEPCat. Its scientific potential is well exemplified through plots and brief discussions. The manuscript is already well written and reviewed.
I raise only minor comments aimed at clarifying some points and provide a few suggestions that the author may choose to implement or not.
Comments:
1. The second change in the catalogue described in lines 100-101 is poorly informative. Could the author clarify this point? Otherwise, if the author does not wish to emphasize it in the text, I suggest removing it in its current form, as it raises unnecessary curiosity for the reader.
2. In Figure 3, the author could indicate the magnitude range, as done in Figure 5 for stellar mass. Alternatively, I recommend include a size-scale in the plot.
3. A colour-code related to metallicity in Figure 7 could provide information or a proof of concept related to incidence of 'Hot Jupiters' and higher metallicity environments.
4. I apologize if I missed this information in the text, but is there any flag related to planets in multiplanetary systems? If not, I believe this information could be helpful. I'm not sure whether this information would be redundant (based on the planet name), especially when handling a long table during coding. This point is based on the fact that some multiplanetary systems can present planets with remarkable parameters (e.g., 'higher' eccentricities).
5. For a future update of TEPCat, I suggest the inclusion of (projected) rotational velocity values for the host stars. Expanding the information on the host stars could be attractive to users from a broad range of stellar areas.
Author Response
1. The second change in the catalogue described in lines 100-101 is poorly informative. Could the author clarify this point? Otherwise, if the author does not wish to emphasize it in the text, I suggest removing it in its current form, as it raises unnecessary curiosity for the reader.
RESPONSE: Done.
2. In Figure 3, the author could indicate the magnitude range, as done in Figure 5 for stellar mass. Alternatively, I recommend include a size-scale in the plot.
RESPONSE: Done.
3. A colour-code related to metallicity in Figure 7 could provide information or a proof of concept related to incidence of 'Hot Jupiters' and higher metallicity environments.
RESPONSE: This was tried but not used, as we found it to make the plot harder to interpret due to the increased use of colour for the background points.
4. I apologize if I missed this information in the text, but is there any flag related to planets in multiplanetary systems? If not, I believe this information could be helpful. I'm not sure whether this information would be redundant (based on the planet name), especially when handling a long table during coding. This point is based on the fact that some multiplanetary systems can present planets with remarkable parameters (e.g., 'higher' eccentricities).
RESPONSE: This would be a useful modification to the catalogue. It has been added to the "to-do" list for the future.
5. For a future update of TEPCat, I suggest the inclusion of (projected) rotational velocity values for the host stars. Expanding the information on the host stars could be attractive to users from a broad range of stellar areas.
RESPONSE: This would also be a useful modification to the catalogue, and indeed is already on the "to-do" list.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe paper thoroughly presents the Transiting Extrasolar Planet Catalogue (TEPCat), which provides the most up-to-date and reliable parameters for the known population of transiting planets. TEPCat is widely used by the community; however, until now, it has lacked a dedicated paper describing the motivation, content, and criteria adopted by the author to create the catalogue. This manuscript will certainly be an extremely useful contribution to the field.
I am delighted to recommend publication of this valuable manuscript to the editor. I have a few minor comments and suggestions that I hope the author will find constructive and helpful for improving the paper (see below).
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Section 1. Introduction. I suggest explicitly stating (also) here that the catalogue is actively maintained by the author. This clarifies the long-term utility and reliability of the resource for the reader.
Section 3. Line 109: transit length ---> transit duration.
Section 3. Lines 122-124. "Anyone using TEPCat to plan observations for which precise timings are necessary should check the literature in advance for reports of transit timing variations." ---> If this is not already stated on the TEPCat website, it should be added there as well to keep users informed.
Section 3. Lines 129-130. "Upper limits are taken from the literature so cannot be made consistent: the most commonly quoted limits are 1sigma, 3sgima and 95%." ----> If this is not already stated on the TEPCat website, it should be added there as well to keep users informed.
Section 3. Pages 3-4. The author lists the calculated parameters implemented in TEPCat. In many literature cases, the semi-major axis derived from a/R* and R* is inconsistent with the value derived from Kepler's third law using Porb and M*. This discrepancy usually stems from inconsistencies between the spectroscopic stellar density and the transit-derived stellar density. Could the author clarify how TEPCat handles such cases to ensure internal consistency among the reported parameters?
Section 3. Lines 157-161. "The unit RJup used in TEPCat is the equatorial radius of Jupiter 71492 km. The reader should beware that planetary sizes are occasionally expressed in units of the volume-mean radius of Jupiter (69911 km), which differs from the equatorial radius because Jupiter is a fast rotator (its rotation period is approximately 10 hours) and thus oblate." ---> The author uses the word "expressed" in relation to the data. It is unclear if this is intended to mean "published in the original literature" or "reported within the TEPCat catalogue." I suggest replacing "expressed" with a more specific term like "published," "reported," or "listed" to avoid ambiguity.
Section 3. Lines 162-175. The author states that the Obliquities table contains "all known measurements of the sky-projected and true orbital obliquities." I would like to ask if TEPCat also includes the stellar spin inclination (i*), which is required to determine the true obliquity. For the sake of completeness, it should be specified whether this parameter is explicitly listed in the table.
Section 3. Lines 172-173. "For the convenience of users, an extra table is available in TEPCat which collects all relevant information for each planet from the three tables described above." ---> Could the author clarify if this summary table also includes the measurements of the (sky-projected or true) spin-orbit angle? If so, it would be helpful to state whether it includes just the most recent measurement or all available measurements for each system.
Section 4. Page 5. Planet-BD mass limit (13 Mjup). ---> If this is not already stated on the TEPCat website, it should be added there as well to keep users informed.
Section 4. Lines 195-198. "This complexity is again important but unwelcome, so a dividing line is drawn at a mass of 75 MJup: less massive objects are taken to be BDs or TEPs, and more massive objects are assumed to be stars." ---> If this is not already stated on the TEPCat website, it should be added there as well to keep users informed.
Section 4. Line 200. DEBCat ---> I suggest spelling out the acronym.
Section 4. Lines 207-209. "The decision was made to include any system with Rb < 0.5 RJup, because they are unambiguously planetary, but not to include larger objects because their nature might be unclear." ---> If this is not already stated on the TEPCat website, it should be added there as well to keep users informed.
Section 6. Figure 5. I suggest adding a color bar to either the right, or left side of this plot. This would allow the reader to easily visualize and interpret the color-coded values.
Section 6. Figure 6. Same as before: I suggest adding a color bar to either the right, or left side of this plot. This would allow the reader to easily visualize and interpret the green shade-coded values and their corresponding scales.
Section 6. Figure 6. The author mentions that the Obliquities table contains "all known measurements of the sky-projected and true orbital obliquities." I suggest clarifying the criteria used to select specific lambda (sky-projected) values for Figure 6, in cases where multiple measurements exist for the same system.
Section 8. Lines 387-388. The author states that secondary eclipses occur at phase 0.5. It should be noted that this is only strictly true for circular orbits, or for eccentric orbits where the line of apsides aligns with the line of sight. I suggest adding a short note to the paper.
Section 8. Figure 9. The phase curve has been added to the light curve. However, it is not mentioned in the caption/main text.
Author Response
Section 1. Introduction. I suggest explicitly stating (also) here that the catalogue is actively maintained by the author. This clarifies the long-term utility and reliability of the resource for the reader.
RESPONSE: This is covered by the existing "It is regularly updated..." in the first paragraph.
Section 3. Line 109: transit length ---> transit duration.
RESPONSE: Changed.
Section 3. Lines 122-124. "Anyone using TEPCat to plan observations for which precise timings are necessary should check the literature in advance for reports of transit timing variations." ---> If this is not already stated on the TEPCat website, it should be added there as well to keep users informed.
RESPONSE: Done.
Section 3. Lines 129-130. "Upper limits are taken from the literature so cannot be made consistent: the most commonly quoted limits are 1sigma, 3sgima and 95%." ----> If this is not already stated on the TEPCat website, it should be added there as well to keep users informed.
RESPONSE: Done.
Section 3. Pages 3-4. The author lists the calculated parameters implemented in TEPCat. In many literature cases, the semi-major axis derived from a/R* and R* is inconsistent with the value derived from Kepler's third law using Porb and M*. This discrepancy usually stems from inconsistencies between the spectroscopic stellar density and the transit-derived stellar density. Could the author clarify how TEPCat handles such cases to ensure internal consistency among the reported parameters?
RESPONSE: No effort is made to check published papers for consistency, although obvious errors will be noticed and investigated. Inconsistencies can also arise if a new study is published reporting new values for some properties of a system, e.g. measuring a new mass and radius of a planet but not also giving its density or surface gravity. In such cases the older values of some properties are removed from TEPCat to avoid inconsistencies.
Section 3. Lines 157-161. "The unit RJup used in TEPCat is the equatorial radius of Jupiter 71492 km. The reader should beware that planetary sizes are occasionally expressed in units of the volume-mean radius of Jupiter (69911 km), which differs from the equatorial radius because Jupiter is a fast rotator (its rotation period is approximately 10 hours) and thus oblate." ---> The author uses the word "expressed" in relation to the data. It is unclear if this is intended to mean "published in the original literature" or "reported within the TEPCat catalogue." I suggest replacing "expressed" with a more specific term like "published," "reported," or "listed" to avoid ambiguity.
RESPONSE: changed "expressed" to "reported"
Section 3. Lines 162-175. The author states that the Obliquities table contains "all known measurements of the sky-projected and true orbital obliquities." I would like to ask if TEPCat also includes the stellar spin inclination (i*), which is required to determine the true obliquity. For the sake of completeness, it should be specified whether this parameter is explicitly listed in the table.
RESPONSE: No, orbital and rotational inclinations are not included. This would be good to include, but would require significant additional work. Readers can easily conclude that inclinations are not included because they are not mentioned in any of the tables.
Section 3. Lines 172-173. "For the convenience of users, an extra table is available in TEPCat which collects all relevant information for each planet from the three tables described above." ---> Could the author clarify if this summary table also includes the measurements of the (sky-projected or true) spin-orbit angle? If so, it would be helpful to state whether it includes just the most recent measurement or all available measurements for each system.
Section 4. Page 5. Planet-BD mass limit (13 Mjup). ---> If this is not already stated on the TEPCat website, it should be added there as well to keep users informed.
RESPONSE: It is already included.
Section 4. Lines 195-198. "This complexity is again important but unwelcome, so a dividing line is drawn at a mass of 75 MJup: less massive objects are taken to be BDs or TEPs, and more massive objects are assumed to be stars." ---> If this is not already stated on the TEPCat website, it should be added there as well to keep users informed.
RESPONSE: It is already included.
Section 4. Line 200. DEBCat ---> I suggest spelling out the acronym.
RESPONSE: Done.
Section 4. Lines 207-209. "The decision was made to include any system with Rb < 0.5 RJup, because they are unambiguously planetary, but not to include larger objects because their nature might be unclear." ---> If this is not already stated on the TEPCat website, it should be added there as well to keep users informed.
RESPONSE: It is already included.
Section 6. Figure 5. I suggest adding a color bar to either the right, or left side of this plot. This would allow the reader to easily visualize and interpret the color-coded values.
RESPONSE:
Section 6. Figure 6. Same as before: I suggest adding a color bar to either the right, or left side of this plot. This would allow the reader to easily visualize and interpret the green shade-coded values and their corresponding scales.
RESPONSE: This would be difficult to do (the author uses IDL and colour bars are a pain in the neck) and make the figure even busier, so has not been added.
Section 6. Figure 6. The author mentions that the Obliquities table contains "all known measurements of the sky-projected and true orbital obliquities." I suggest clarifying the criteria used to select specific lambda (sky-projected) values for Figure 6, in cases where multiple measurements exist for the same system.
RESPONSE: Normally the most recent or the most reliable are chosen as the representative value for an individual system. The choice is usually easy to make.
Section 8. Lines 387-388. The author states that secondary eclipses occur at phase 0.5. It should be noted that this is only strictly true for circular orbits, or for eccentric orbits where the line of apsides aligns with the line of sight. I suggest adding a short note to the paper.
RESPONSE: Good point. This has been clarified.
Section 8. Figure 9. The phase curve has been added to the light curve. However, it is not mentioned in the caption/main text.
RESPONSE: The phase curve was included by default, by including the reflection effect in the JKTEBOP model, but is not discussed in the paper at all.
Reviewer 3 Report
Comments and Suggestions for AuthorsThe article 'TEPCat: the Transiting Extrasolar Planet Catalogue' by J. Southworth presents a thorough summary of the author's online electronic repository of the properties of transiting exoplanet (and brown dwarf) and their host stars taken from refereed publications or computed based on those results.
Its motivation, content, and form are all clearly described in the manuscript. Since this is a widely used community resource, a published update on its status (following the previous 2011 MNRAS paper) is welcome. As an archive summary the scientific results are minimal, but the manuscript includes useful context regarding the properties of the detected transiting exoplanet population visualised from TEPCat and with reference to the literature.
I have a few minor comments for the author to consider but consider the manuscript is acceptable for publication as it stands.
- line 47: perhaps define what a 'normal' star is in this context.
- line 65: perhaps include the magnitude limits for the various surveys (CoRoT, Kepler, PLATO, etc.) in this paragraph to quantify 'faint' and 'bright'.
- line 140: are the uncertainties on the parameters used in calculation also propagated?
- line 210: the de-prioritisation of including large volume exoplanet (candidates) from automated surveys into TEPCat is understandable given the labour involved, but since this is the general direction of travel for data sets in astronomy, some comment (or even a sub-section) on the future of TEPCat could be of interest, i.e. how does the author foresee TEPCat's data induction evolving over the next few years into the era of large scale all-sky photometric surveys? (for example, adding a webform for authors to submit the relevant data for inclusion in TEPCat, visualisation tools on the webpage)
Author Response
line 47: perhaps define what a 'normal' star is in this context.
RESPONSE: Added "(main sequence)".
line 65: perhaps include the magnitude limits for the various surveys (CoRoT, Kepler, PLATO, etc.) in this paragraph to quantify 'faint' and 'bright'.
RESPONSE: This has been done.
line 140: are the uncertainties on the parameters used in calculation also propagated?
RESPONSE: No. This is not possible with the available data because standard error-propagation techniques do not work properly on the products of MCMC simulations.
line 210: the de-prioritisation of including large volume exoplanet (candidates) from automated surveys into TEPCat is understandable given the labour involved, but since this is the general direction of travel for data sets in astronomy, some comment (or even a sub-section) on the future of TEPCat could be of interest, i.e. how does the author foresee TEPCat's data induction evolving over the next few years into the era of large scale all-sky photometric surveys? (for example, adding a webform for authors to submit the relevant data for inclusion in TEPCat, visualisation tools on the webpage)
RESPONSE: This is an important topic but was not included in the manuscript because no changes are planned. Improvements to the database implementation, the option to submit data, and the addition of visualisation tools, are all significant work and exceed the time available for maintenance of the database. I hope to do these in future, but this would require additional funding so cannot be guaranteed.
Reviewer 4 Report
Comments and Suggestions for AuthorsAs the author states, "TEPCat (the Transiting Extrasolar Planet Catalogue) is an online catalogue of transiting extrasolar planets (TEPs) and their physical properties." This is a full list of TEPs and brown dwarfs found during TEP searches. The author is very right to describe the list and the values therein.
I have gone over the manuscript three times. I do not see any mistakes in the author's choice of writing.
I say this is a manuscript that is ready for publication.
Author Response
We thank the reviewer for their positive comments. They raised no point on which the manuscript might be corrected. Therefore we give below the additional small changes we have made to the manuscript in the course or preparing the revised version.
ADDITIONAL CHANGES:
1) All plots were updated to the contents of TEPCat as of 1st February 2026.
2) Table 4 was updated to the contents of TEPCat as of 1st February 2026.
3) A few small typos were fixed.
4) The reference list was modified to include ten authors for all papers with these or more authors.
