Exoplanet Criteria for Inclusion in the Archive

There are numerous exoplanet-related catalogs available online, each with its own criteria on which objects to include in their list of planets. As such, users may notice different numbers associated with each information source.

The NASA Exoplanet Archive has adopted a policy of including and classifying all objects as planetary that meet the following criteria:

  • The mass (or minimum mass) is equal to or less than 30 Jupiter masses.
  • Sufficient follow-up observations and validation have been undertaken to deem the possibility of the object being a false positive unlikely
  • The above information along with further orbital and/or physical properties are available in peer-reviewed publications.

An example of an object that has not been included is the companion to SCR 1845. This object was detected via imaging and has an estimated mass larger than the 30 Jupiter mass criteria stated above.

Values Computed by the Exoplanet Archive

For HD 45364 b and c from Mayor et al 2004, the time of periastron passage is computed from the period, base date, longitude of periastron omega (ω) and mean longitude of the date lambda (λ) as follows:

tperi= base date - P* (λ-ω)/360 = basedate - P*λ/360 - P*ω/360

where P is period and M = λ-ω is the mean anomaly and the error is propagated from errors in the period and angles as follows:

σt,peri2 = σP2 * ((λ-ω)/360)2 + (σω2λ2) *(P/360)2

These criteria may change in the future as our understanding of exoplanets improves. If you find an error or have an update on the parameter values on our site, please submit a Helpdesk ticket. We will confirm and update our values accordingly.

Multiple and Mutually Incompatible Values

For papers that report multiple values for an exoplanet or host star parameter, a single value is chosen as the default, and the user can access the paper for the additional values. For papers that report a range of values for an exoplanet or host star parameter, as opposed to a single value and uncertainties, we adopt the mean of the range and the single value and the range/2 as the uncertainty. For example, Liu et al. (2011) reports a mass for CFBDSIR J1458+1013 b of 6-15 Jupiter masses. We adopt a value of 10.5+/-4.5 Jupiter masses.

Targets Removed from the Archive

Occasionally, we will remove an object from the archive when its status changes. A list of these objects are documented on the Targets Removed from the Archive page.

Discrepancies Between Literature and Archive Values

Occasionally, planet parameters in the archive are different from those in the published literature. These discrepancies are identified by the comments from the scientific community, and are confirmed by the authors. We track these errors in the table below, which is updated periodically.

Host NamePlanet LetterParameterLiterature ValueExoplanet Archive ValueLiterature ReferenceNotes
Kepler-10 c Orbital Period 42.29485 days 45.29485 days Fressin et al. 2011
Typo in published period in Table 2, confirmed with author
CoRoT-20 b Distance to System 1.23+/-120 kpc 1.23+/-0.12 kpc Deleuil et al. 2012 Typo in Table 3
Fomalhaut b

Orbit Semi-Major Axis

119 AU 115 AU Kalas et al 2008 119 AU is quoted in the abstract, but 115 AU appears repeatedly throughout the paper
GJ 3470 b RV Semi-Amplitude 0.00901+/-0.00075 m/s 9.01+/-0.75 m/s Bonfils et al. 2012 Unit in Table 2 should be km/s
HD 203030 b Planet Letter B b Metchev & Hillenbrand 2006 The Exoplanet Archive adopts lower-case letters for planetary mass companions

HAT-P-27

b RV semi-amplitude 0.0912+/-0.002 m/s 91.2+/-2 m/s Brown et al. 2012 Unit in Table 7 should be km/s
Kepler-46 d Planet Letter c d Rowe et al. 2014 Typo, Kepler-46 c already exists in literature
HD 60532 b, c Stellar Surface Gravity -3.83 3.83 Desort et al. 2014 Typo in Table 1

Last update: 6 March 2014