Photometric Analysis of the β Cephei Stars BW Crucis and CV Crucis and Their Host Cluster NGC 4755
Volume 53 number 2 (2025)
- Denis Levine
- Stanford Online High School, Academy Hall Floor 2 8853, 415 Broadway, Redwood City, CA 94063; denisl3@proton.me
- Khensa Musaddequr Rahman
- Stanford Online High School, Academy Hall Floor 2 8853, 415 Broadway, Redwood City, CA 94063; khensamrahman@gmail.com
- Nicholas Dunn
- Wellington College, Crowthorne, Berkshire, RG45 7PU; nicholas.jasper.dunn@gmail.com
- Leonid Vishnevskiy
- Stanford Online High School, Academy Hall Floor 2 8853, 415 Broadway, Redwood City, CA 94063; leonid59@ohs.stanford.edu
- Kalée Tock
- Stanford Online High School, Academy Hall Floor 2 8853, 415 Broadway, Redwood City, CA 94063; kaleeg@stanford.edu
Abstract
We study the brightness over time of BW Crucis and CV Crucis, two beta Cephei stars in the open cluster NGC 4755. Archival photometry from the Transiting Exoplanet Survey Satellite is examined for periodicities using an iterative prewhitening method based on the Lomb-Scargle periodogram. Up to 28 frequencies are found for BW Cru and up to 52 for CV Cru. The former’s power spectrum is dominated by high (> 1 d^–1) frequencies, while the latter contains an abundance of lower (< 1 d^–1) ones. Furthermore, to situate these targets in their stellar environment, we make use of the DBSCAN cluster identification algorithm to locate a group of points in proper motion space from Gaia Data Release 3 astrometry. Manual fitting of the isochrone parameters in the Astromancer program allows us to obtain values similar to those in the scientific literature, though our extinction differs by 0.09 magnitude and the overall uncertainties are high.