The Gateway to the Seagull Nebula(IC 2177), NGC 2335 is an open star cluster first discovered by William Herschel in 1785. This cluster is situated in a faint constellation near the equator, named Monoceros and is home to about 25 stars. It is an intermediate cluster with an age of about 130 million years, located approximately 4300 light years away from us.
Although there haven’t been many recent studies on the cluster, a notable one was conducted in 1973 by J.J. Claria, utilizing photoelectric photometry as the primary method. This involved the use of a photomultiplier and integrator, which was a standard technique at the time. However, in modern photometric observations, CCDs are more commonly employed due to their advantages such as higher sensitivity, wider spectral coverage, and faster data acquisition. Despite the relatively lower sensitivity of the techniques used in the 1973 study compared to modern CCDs, the data obtained, including age determination and information gathered from colour-magnitude diagrams, remains remarkably accurate. This highlights the effectiveness of the methods employed in providing valuable insights into the cluster’s characteristics and properties.
To investigate this particular cluster and explore the relationships between colour, brightness and age, I conducted a comprehensive observational campaign. Using PROMPT-MO-1, Prompt5, and Prompt6 telescopes equipped with B, V, and R filters, I captured a series of 15 images. Each filter was exposed for durations of 60 seconds for B, 35 seconds for V, and 20 seconds for R. This process was repeated five times with one-hour intervals to ensure robust data collection.
Following the image acquisition, I utilized Afterglow to process and generate a photometry CSV file. This file was then uploaded to Cluster Astromancer for further analysis. The analysis involved several steps, including field star removal, archive fetching, and isochrone matching. Using the E(B-V) value obtained from the isochrone matching process I de-reddened the cluster’s stacked images:
Based on the data obtained, the following basic results were derived:
1. Distance: The calculated distance to the cluster is approximately 1.58 kiloparsecs or 5153.271 light-years. While this value is not precisely accurate, it closely approximates the true distance to the cluster.
2. Velocity Dispersion: The velocity dispersion of the cluster is determined to be 0.81 milliarcseconds per year (mas/yr), providing insight into the dynamics of the cluster members.
3. Age Estimation: The log age of the cluster is calculated to be 8.25 log years. This estimation offers valuable information regarding the evolutionary stage of the cluster and defines it as an intermediate cluster.
The utilization of multiple telescopes with varying exposure durations and filters helped me to ensure comprehensive coverage of the cluster’s photometric properties across different wavelengths. The use of Skynet for data collection and Afterglow for initial processing, streamlined the observational workflow and facilitated efficient analysis of the collected data.
During my thorough analysis through the B-V vs V colour-magnitude diagram and BP-RP diagram displayed below:
                           
I detected the presence of blue stragglers within the cluster. These stars, observed in the colour-magnitude (B-V vs V) diagram, displayed characteristics such as being bluer and brighter than others at or near the cluster’s turnoff point. This phenomenon suggests potential scenarios like binary star interactions or stellar mergers. No evidence of a nebula associated with the cluster was found in the images examined. However, it’s crucial to acknowledge the possibility that specialized imaging techniques or higher-resolution observations might give further insights. Another notable finding from our examination of the colour-magnitude diagrams is the presence of giant stars within the cluster population, noticeable at the top right of the diagrams.
Throughout our analysis, I encountered a significant challenge posed by field stars contaminating the cluster region. This necessitated the implementation of meticulous field star removal techniques to accurately isolate the cluster members, ensuring the integrity of our findings and interpretations.
Having completed my analysis of NGC 2335, this FYRE project for cluster analysis marks a significant milestone in my scientific journey. Despite the challenges encountered, the process of investigating its dynamics and characteristics has been immensely rewarding. The detection of blue stragglers and giant stars offers valuable insights into stellar interactions. I’m fulfilled by the opportunity to contribute to our understanding of the universe and eagerly anticipate future discoveries in cosmic exploration.