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. At the NASA Exoplanet Archive, we monitor the literature for relevant planet publications from both NASA and non-NASA observing resources and include data from ground and space-based observations.

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.
  • The planet is associated with a host star (i.e. not free floating)
  • 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.

The Exoplanet Archive team works to include the relevant parameter values from each reference. In some cases, these values may be assumed or taken from other literature references. Please use the provided links to see the details for any parameter value.

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.

Default and Multiple Parameter 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. Selection of the default parameter set is based on the number and precison of the published parameters, and the default reference is displayed in both the Confirmed Planet table and on the Overview page. 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 as 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 is given on the Targets Excluded from the Archive page.

Discrepancies Between Literature and Archive Values

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Last update: 2 December 2015