The DOI matches its Crossref record; 1 of the 1 references it cites were found in a registry or an index.
A Neptune‐Mass Planet Orbiting the Nearby M Dwarf GJ 436
Open accessAbstract
We report precise Doppler measurements of GJ 436 (M2.5 V) obtained at Keck Observatory. The velocities reveal a planetary companion with orbital period of 2.644 days, eccentricity of 0.12 (consistent with zero), and velocity semiamplitude of K = 18.1 m s -1 . The minimum mass ( M sin i ) for the planet is 0.067 M Jup = 1.2 M Nep = 21 M Earth , making it the lowest mass exoplanet yet found around a main-sequence star and the first candidate in the Neptune-mass domain. GJ 436 (mass = 0.41 M ☉ ) is only the second M dwarf found to harbor a planet, joining the two-planet system around GJ 876. The low mass of the planet raises questions about its constitution, with possible compositions of primarily H and He gas, ice/rock, or rock-dominated. The implied semimajor axis is a = 0.028 AU = 14 stellar radii, raising issues of planet formation, migration, and tidal coupling with the star. GJ 436 is more than 3 Gyr old, based on both kinematic and chromospheric diagnostics. The star exhibits no photometric variability on the 2.644 day Doppler period to a limiting amplitude of 0.0004 mag, supporting the planetary interpretation of the Doppler periodicity. Photometric transits of the planet across the star are ruled out for gas giant compositions and are also unlikely for solid compositions. As the third closest known planetary system, GJ 436 warrants follow-up observations by high-resolution optical and infrared imaging and by the Space Interferometry Mission .
Overview
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Verification
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Citations
Cites
Queloz, D., Henry, G. W., Sivan, J. P., Baliunas, S. L., Beuzit, J. L., Donahue, R. A., Mayor, M., Naef, D., Perrier, C., & Udry, S. (2001) · Astronomy and Astrophysics · doi:10.1051/0004-6361:20011308 · Cited by 913 · cited 1×
“Queloz et al. (2001) and Paulson et al. (2004) have shown that photospheric features such as spots and plages on solartype stars can result in low-amplitude, periodic radial velocity variations capable of mimicking the presence of a planetary companion.”
Self-citation
Cited by
Butler, R. P., Wright, J. T., Marcy, G. W., Fischer, D. A., Vogt, S. S., Tinney, C. G., Jones, H. R. A., Carter, B. D., Johnson, J. A., McCarthy, C., et al. (2006) · The Astrophysical Journal · doi:10.1086/504701 · Cited by 914
Self-citationCumming, A., Butler, R. P., Marcy, G. W., Vogt, S. S., Wright, J. T., & Fischer, D. A. (2008) · Publications of the Astronomical Society of the Pacific · doi:10.1086/588487 · Cited by 892
Self-citationThe Occurrence and Architecture of Exoplanetary Systems
Winn, J. N., & Fabrycky, D. C. (2015) · Annual Review of Astronomy and Astrophysics · doi:10.1146/annurev-astro-082214-122246 · Cited by 891
Mass‐Radius Relationships for Solid Exoplanets
Seager, S., Kuchner, M., Hier‐Majumder, C. A., & Militzer, B. (2007) · The Astrophysical Journal · doi:10.1086/521346 · Cited by 829
THE OCCURRENCE RATE OF SMALL PLANETS AROUND SMALL STARS
Dressing, C. D., & Charbonneau, D. (2013) · The Astrophysical Journal · doi:10.1088/0004-637x/767/1/95 · Cited by 749
Metadata
- Authors
- Butler, R. P., Vogt, S. S., Marcy, G. W., Fischer, D. A., Wright, J. T., Henry, G. W., Laughlin, G., & Lissauer, J. J.
- Venue
- The Astrophysical Journal
- Publisher
- American Astronomical Society
- Published
- 2004-12-10
- Volume
- 617
- Issue
- 1
- Pages
- 580-588
- ISSN
- 0004-637X (ISSN-L)
- 1538-4357
- OpenAlex
- W2123206376
- Cited by
- 479
- References
- 1
- FWCI
- 21.86
- Type
- journal article
- Language
- en
- Open access
- bronze
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
How to cite
Cite CoChat for the checks on this page, and the paper for its own findings.
- This page
- CoChat. (2026). Citation check: A Neptune‐Mass Planet Orbiting the Nearby M Dwarf GJ 436. https://app.cochat.ai/papers/10.1086/425173
- The paper
- Butler, R. P., Vogt, S. S., Marcy, G. W., Fischer, D. A., Wright, J. T., Henry, G. W., Laughlin, G., & Lissauer, J. J. (2004). A Neptune‐Mass Planet Orbiting the Nearby M Dwarf GJ 436. The Astrophysical Journal. https://doi.org/10.1086/425173
Data sources
Bibliographic data: Semantic Scholar, OpenAlex, Crossref.
Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).
Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.
