Abstract: Dr. Gary Hawkins (Blossom Valley Small Telescope Observatory), Red Dwarf Group Coordinator, writes: “This campaign invites AAVSO members and collaborators to participate in a coordinated, high-cadence photometric and spectroscopic study of flare stars. The campaign targets stars of magnitudes 9 to 13, including EV Lacertae (EV Lac) and AD Leonis (AD Leo). Observations will commence immediately and continue for two to three years.”
Building on insights from the previous campaign (Campaign #1) announced in AAVSO Alert Notice 789 in 2022, this follow-up campaign aims to deepen our understanding of flare activity in low-mass stars through multi-wavelength observations, contributing to ongoing analyses of high-energy stellar environments.
Justification: Campaign #2 focuses on the observation and scientific investigation of flare stars to provide further insight into their complex nature. The Red Dwarf Group is a worldwide collaboration of experienced observers and scientists dedicated to advancing the study of red dwarf flare stars. Since our inception, we have achieved exciting results by leveraging a global network of telescopes spanning from Europe to the west coast of the United States. This setup allows us to conduct extended, high-cadence observations, monitoring our targets for many hours each night and sometimes over weeks or months. Our research goals include developing robust flare-frequency distributions, assessing the statistical significance in FFD changes, and exploring more precise flare temperature modeling.
The RDG plans to publish the results in peer-reviewed astronomical journals.
The alert mentions a 30 sec cadence. Can you clarify a bit? If I am taking exposures of B and V filters do you want a set every 30 secs (might be difficult)? Also, 30 secs would probably only give time for one exposure as opposed to multiple which could be averaged. Is that your intent as well?
We are seeking continuous high-cadence photometric observations. If you’re using Johnson or Cousins filters, choose either B or V; avoid switching between filters during the session. If you are using tri-color imaging, red, green, and blue channels can be captured simultaneously, which is ideal.
To capture the full profile of a flare, aim for a 30-second cadence. The leading edge of a flare occurs over a span of minutes, so a high cadence is essential for detailed data. A 30-second exposure mitigates the effects of atmospheric scintillation.
For filters, note that a B filter will show a more pronounced relative flux change compared to a V filter, which can be particularly useful for flare studies.
For those interested in observing stellar flares, the Red Dwarf Group’s primary target has shifted to AD Leo, as EV Lac is now low in the western sky and less favorable for observations.
We encourage you to consider requesting membership in the Red Dwarf Group. Most of our communications take place on our groups.io page, where you’ll find updates, resources, and collaboration opportunities. Membership also allows you to join our biweekly Zoom calls, where we discuss progress, results, challenges, and more.
If you’re interested in joining, please email me at astrogary8@gmail.com to request membership. We’re always excited to welcome new contributors to our campaign, and all experience levels are welcome.
Based on your comment, you would prefer to have a CMOS TR, TB, TG debayered report at 30 second intervals rather than a B or V? Pardon, my dumb question. I’m somewhat new to AAVSO and have only submitted transformed B and V.
It would actually be easier for me to use my Mallincam DS10CTEC camera and just let it run but I didn’t think that T* magnitudes would be useful. It sounds like what you are really looking at is the relative change in magnitude to recognize the flare and the accuracy of the magnitude is maybe less important.
As long as the filter profile is known, both Johnson & Cousins (J&C) B and V filters, or tri-color measurements, are acceptable. B and V filters have the advantage of being part of a standardized system, while tri-color imaging allows you to capture color information in a single exposure. In fact, all of my imaging to date on EV Lac has been in tri-color using a ZWO ASI 533MC.
For observers using B and V filters, we will coordinate efforts within regions to optimize data collection—one observer will focus on V, while the other will use B. For tri-color imaging, such coordination is generally less necessary.
Given the diverse range of equipment used by participants, we chose not to limit observers to specific filters. We are confident that we can align data from J&C, tri-color, and even Sloan filters as needed to achieve consistent and reliable results.
Thanks. I’ll probably do most of my imaging with all night session using a Mallincam DS10cTEC on a Planewave CDK 12.5. I have to do some work to rewrite a Pixinsight script that I have for image calibration and prep for submission to Vphot. I do B and V right now, so I have to add in the DeBayer step. I’ll probably start in a week or two. I’ll update the spreadsheet with my planned/actual activity as this firms up.
Regarding alternating filters. As I understand, you prefer B instead of V? No problem for me, but I think putting a V frame in every few B frames is always nice. This would be useful for aligning with other observers’ observations and allowing transformation coefficients to be applied. So, I think alternating BBBBBVBBBBBV with 30 second exposures would be a good option.
I find this to be a very intriguing idea. The filter wheel isn’t overly burdened, and incorporating additional information from both colors enhances the alignment of AID data and allows for color calculations. Furthermore, minimal structural data is lost when resolving the flare in the primary band.
Below is a sample taken with a Seestar S50 under Bortle 9 skies (alt az, 10 sec exposures, green channel photometry done in ASTAP, SNR around 150). Would such data be useful for the project?
First chart below is the same sample stacked (3x10s subs). However, it’s hard to tell where the right balance is because smoothing can also lead to loss of information (i.e. loss of granularity in terms of timestamps and amplitude). For example, the second chart shows the initial non-stacked data with a simple rolling average to guide the eye (orange line). The peak displays a more complex structure than in the stacked sample and the transitions are sharper (which of course could also be an artefact).
Obviously, I am not concerned about this specific sample and whether it includes a flare or not. My question was of general nature with respect to Seestar collected data and in order to understand whether it makes sense to allocate time to this project. The blue channel proved quite tricky to analyze, even if stacked, less than 30% of the data could be evaluated by ASTAP.
