Thursday, October 10, 2024

10/10/24

 We used the Lomb-Scargle Periodogram (as implemented by astropy) to search for periodic signals in each band of all 539 stars' light curves.
Each such light curve was analyzed in three ways:
\begin{itemize}
    \item unmodified;
    \item detrended with a second-order polynomial;
    \item detrended with a fourth-order polynomial.
\end{itemize}
Objects that had a false-alarm probability of $10^{-5}$ or smaller\footnote{Details of how the threshold of $10^{-5}$ was chosen are given in the Appendix.} in any band under any detrending method were selected as `periodic candidates`.
Each periodic candidate was further analyzed by inspection of all periodograms and all folded light curves.
Whenever a clear `best` period was identified via this approach (often by looking for some consensus between bands and/or methods), we identified a period and flagged the object as a periodic variable.
\tsr{X number} of objects were thus identified as periodic variables.

Thursday, April 14, 2022

4/14/22

 Variable stars are selected via two methods: their periodicity (via
the Lomb-Scargle periodogram) and their general variability (via
the Stetson variability index). We identified variable stars using 3
criteria:
(i) an automated Stetson selection;
(ii) a periodic selection using the Lomb-Scargle periodogram;
and
(iii) a manual selection of light curves with high Stetson indices
but with one or more photometric error flags in each band.
Each of these selections is elaborated upon in the following subsec-
tions. We have detected 244 variable objects out of 658 analyzed
targets.

Friday, July 30, 2021

7/30/21

From mid-infrared observations of YSOs, Young et al. (2015) support ages of2Myr for IC 348 and.1Myr for NGC 1333.

Thursday, July 29, 2021

7/29/21

Our study comprises very low mass stars (.0.2) and browndwarfs (.0.08, i.e.,.80Jup) in three star-forming re-gions: the Orion Nebula Cluster (ONC), NGC 1333, and IC 348.Among young (13Myr) stars and brown dwarfs, mass is closelycorrelated with spectral type and effective temperature (eff); thehydrogen-burning limit of0.08corresponds to a spectral typeofM6 and an effective temperature of3000K (Luhman et al.2003; Luhman 2012). In the ONC, we rely on membership andeffestimations from Robberto et al. (2020); in NGC 1333 and IC 348,we rely on membership and spectral type estimates from Luhmanet al. (2016).

Wednesday, July 21, 2021

7/21/21

 Rodríguez-Ledesma et al. (2009) performed a comparison of ro-tation among both stellar and substellar-mass YSOs.

Monday, July 19, 2021

7/19/21

Variability among low-mass stars and brown dwarfs in \ic{} has been previously studied by \citet{ghosh_fast_2021}.

Thursday, July 8, 2021

7/8/21

 The shortest periods for young brown dwarfs are $\sim 1$~hr \citep{tannock_weather_2021}.