The photometric periods of rapidly rotating field ultra-cool dwarfs

Miles-Páez, Paulo A.; Metchev, Stanimir; Benjamin, George

doi:10.1093/mnras/stad273

Cited by 3 publications

(2 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We interpret these as ECMI emission and refer to these two bursts as B1 and B2 hereafter. The time interval between the bursts' maxima is 2.70 ± 0.02 hours, which is close to (but different from) the rotation period [2.84140 ± 0.00039 hours (15)]. The right circularly polarized (RCP) emission varies slowly during the observation, reaching a maximum before the bursts occur.…”

Section: Radio Observations Of Lsr J1835+3259mentioning

confidence: 66%

“…On 15 June 2021, we observed the brown dwarf (spectral type M8.5) LSR J1835+3259 (also cataloged as 2MASS J18353790+3259545) using the European VLBI Network (EVN). LSR J1835+3259 exhibits a rapid rotation [rotational period 2.84140 ± 0.00039 hours ( 15 )] and is at a distance of 5.6885 ± 0.0015 parsecs ( 16 ) from Earth. Previous studies have shown that it has strong radio emission in both the bursting and quiescent components ( 3 , 9 , 17 – 19 ).…”

Section: Radio Observations Of Lsr J1835+3259mentioning

confidence: 99%

See 1 more Smart Citation

Evidence for a radiation belt around a brown dwarf

Climent,

Guirado,

Pérez-Torres

et al. 2023

Science

View full text Add to dashboard Cite

Ultracool dwarfs are a category of astronomical objects including brown dwarfs and very low-mass stars. Radio observations of ultracool dwarfs have measured their brightness as a function of time (light-curves) and spectral energy distributions, providing insight into their magnetic fields. We present spatially resolved radio observations of the brown dwarf LSR J1835+3259 using very long baseline interferometry, which show extended radio emission. The detected morphology is consistent with the presence of a radiation belt. Comparison with models indicates the radiation belt contains energetic particles confined by magnetic mirroring. We argue that radio emitting ultracool dwarfs possess dipole-ordered magnetic fields with radiation belt-like morphologies and aurorae, similar to those of Jupiter.

show abstract

Section: Radio Observations Of Lsr J1835+3259mentioning

confidence: 66%

Section: Radio Observations Of Lsr J1835+3259mentioning

confidence: 99%

Evidence for a radiation belt around a brown dwarf

Climent,

Guirado,

Pérez-Torres

et al. 2023

Science

View full text Add to dashboard Cite

show abstract

Exploring the photometric variability of ultra-cool dwarfs with TESS

Petrucci,

Gómez Maqueo Chew,

Jofré

et al. 2023

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We present a photometric characterization of 208 ultra-cool dwarfs (UCDs) with spectral types between M4 and L4, from 20-s and 2-min cadence TESS light curves. We determine rotation periods for 87 objects ($\sim 42~{{\ \rm per\ cent}}$) and identify 778 flare events in 103 UCDs ($\sim 49.5~{{\ \rm per\ cent}}$). For 777 flaring events (corresponding to 102 objects), we derive bolometric energies between 2.1 × 1030 and $1.1 \times 10^{34}\ \mathrm{erg}$, with 56 superflare events. No transiting planets or eclipsing binaries were identified. We find that the fraction of UCDs with rotation and flaring activity is, at least, 20 per cent higher in M4–M6 spectral types than in later UCDs (M7–L4). For spectral types between M4 and L0, we measure the slope of the flare bolometric energy–duration correlation to be γ = 0.497 ± 0.058, which agrees with that found in previous studies for solar-type and M dwarfs. Moreover, we determine the slope of the flare frequency distribution to be α = −1.75 ± 0.04 for M4–M5 dwarfs, α = −1.69 ± 0.04 and α = −1.72 ± 0.1 for M6–M7 and M8–L0 dwarfs, respectively, which are consistent with previous works that exclusively analysed UCDs. These results support the idea that independently of the physical mechanisms that produce magnetic activity, the characteristics of the rotational modulation and flares are similar for both fully convective UCDs and partially convective solar-type and early-M stars. Based on the measured UCD flare distributions, we find that ultraviolet radiation emitted from flares does not have the potential to start prebiotic chemistry.

show abstract

A Portrait of the Rotation of Ultra-cool Dwarfs Revealed by TESS

Fontinele,

de Lima,

Messias

et al. 2024

ApJ

View full text Add to dashboard Cite

This study presents the results of a search for rotation signatures in 250 Gaia Data Release 3 ultra-cool dwarfs (UCDs) with TESS light curves (LCs). We identified 71 targets with unambiguous periodicities, of which 61 present rotation signatures and a single-source behavior, with periods between 0.133 and 5.81 days. Five UCDs show double-dip features, namely variations with two periods, one approximately double or half the other. The remaining 10 UCDs with unambiguous variability present a likely nonsingle behavior. We also found 20 UCDs showing complex behavior in their LCs, with noticeable fluctuations and irregular structure, with a few exhibiting apparent changes in their temporal structure. The remaining 159 targets show noisy LCs corresponding to low-amplitude signals, whose temporal variation cannot be easily identified. The distribution of the UCDs with rotation signature in a color–magnitude diagram points to a lack of rotating objects within about 11.5 < M G < 12.5 and G–G RP < 1.5, separating them into two regimes, one mainly composed of less massive late-M stars with P rot ≥ 1.0 day, and another mainly composed of more massive early-M stars with P rot < 1.0 day. It is important to emphasize that by separating stars into age intervals, one observes that UCDs with P rot ≥ 1.0 day tend to be located in regions of younger objects, and, in contrast, those with P rot < 1.0 day are mainly concentrated in regions of older objects. Whether this trend of stars contrasting the sample separation is physical or produced by observational biases is a question to be verified in future studies.

show abstract

The photometric periods of rapidly rotating field ultra-cool dwarfs

Cited by 3 publications

References 58 publications

Evidence for a radiation belt around a brown dwarf

Evidence for a radiation belt around a brown dwarf

Exploring the photometric variability of ultra-cool dwarfs with TESS

A Portrait of the Rotation of Ultra-cool Dwarfs Revealed by TESS

Contact Info

Product

Resources

About