Student or educator? Sign up with your school email and get 6 months of Pro free.
CoChat
Sign Up
Cited by 259

The DOI matches its Crossref record; 34 of the 34 references it cites were found in a registry or an index.

Chromospheric Activity, Rotation, and Rotational Braking in M and L Dwarfs

Open access
Reiners, A., Basri, G.·2008·The Astrophysical Journal
DOI 10.1086/590073
Open this paper in CoChat — free account

Abstract

We present results from a high-resolution spectroscopic survey of 45 L dwarfs, which includes both very low mass stars and brown dwarfs. Our spectra allow us to derive a significant number of new rotational velocities, and discover a slowly rotating (in projected velocity) L dwarf that allows more accurate measurement of spectroscopic rotations for these objects. We measure chromospheric activity (and often its variability) through the Hα emission line. Our primary new result is good evidence that magnetic braking dominates the angular momentum evolution of even brown dwarfs, although spindown times appear to increase as mass decreases. We confirm that activity decreases as effective temperature decreases, although a larger fraction of L dwarfs are active than has previously been reported. Essentially all active objects are also variable. We confirm the lack of a rotation-activity connection for L dwarfs. We find a minimum limit for rotational velocities that increases with later spectral types, rising from near zero in older mid-M stars to more than 20 km s −1 for mid-L objects. There is strong evidence that all L dwarfs are rapid rotators. We derive a braking law that can depend on either temperature or mass which can explain all the rotational results and provides an age dependence for the angular momentum evolution. It is clear that angular momentum loss mechanisms in smaller and cooler objects become more inefficient, starting at the fully convective boundary.

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.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1086/590073

Cites

34 of 34 references verified0 citation errors · 0 not checkable

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.

A few free checks a day · papers already verified open instantly · results are public

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

Show all 34 references

Cited by

See all 259

Metadata

Authors
Reiners, A., & Basri, G.
Venue
The Astrophysical Journal
Publisher
American Astronomical Society
Published
2008-09-10
Volume
684
Issue
2
Pages
1390-1403
ISSN
  • 0004-637X (ISSN-L)
  • 1538-4357
DOI
10.1086/590073
OpenAlex
W1968760357
Cited by
259
References
34
FWCI
11.59
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: Chromospheric Activity, Rotation, and Rotational Braking in M and L Dwarfs. https://app.cochat.ai/papers/10.1086/590073
The paper
Reiners, A., & Basri, G. (2008). Chromospheric Activity, Rotation, and Rotational Braking in M and L Dwarfs. The Astrophysical Journal. https://doi.org/10.1086/590073

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.