Alert Notice 840 announces an observing campaign on the bright, eclipsing, triple system b Per (not beta Per). Please see the notice for details and observing instructions.
There are threads for this campaign under the following AAVSO forums:
Please subscribe to these threads if you are participating in the campaign so you can be updated, ask questions, and join in the discussion!
Many thanks, and Good observing,
Elizabeth O. Waagen, AAVSO HQ
Welcome observers to the b Persei campaign page for the November 2023 eclipse. I will be "hosting" the campaign and keeping folks updated about the progress and sharing compiled light curves. I do some processing with the AAVSO data and create light curves similar to the light curve shown in the Alert Notice.
Hi Dr. Collins,
Per notice, you are also encouraging DSLR observations. Are data from colored cmos also acceptable, and is it okay to have no IR cut filter, or needs to have the IR cut?
Raymond, I believe that CMOS DSLR data would be as useful as traditional DSLR data. Make sure you use the green channel. It is also important to get out-of-eclipse data because different instruments show differing zero points. I later scale all the fluxes from different instruments and observers to match the ooe curves.
Hello. B Per is very bright. We are in the process of commissioning a spectrograph (Lhires III + 14 inch Celestron). I just got the adapter to connect it to our focuser, but if we get it working in time,would spectra be useful for this campaign, and if so, what wavelengths? We have a 600l/mm grating for low-resolution,and a 1200l/mm and 2400 l/mm for higher resolution work.
Hello b Per Observers,
The onset of the eclipse is expected to happen (first contact) some time on Nov. 26 Universal date. Let's get our scopes fired-up and ready, even be prepared to shoot between the clouds if necessary!
The mid-time of the eclipse is Nov. 28.3 UT (early morning hours in Europe). We need "all night" coverage (as long as clear skies permit) between Nov. 26 UT and Dec 1.
Good luck with fickle weather!!
My last reading (UTC 2023/11/26 05:29:46) is comparatively low. Could this already be a first sign of the eclipse? The measuring point was taken shortly before nautical twilight, so I was unable to take any further measurements.
There is a report from ATE (Teofilo Arranz) that he observed a dip to 4.74 mag. We hope to see more data!! I haven't seen Teofilo's data yet.
The eclipse was expected to commence on JD 2470275 which was the night of Nov. 26-27.
We hope all observers with clear skies will try for all-night runs!!!
Anoche pude hacer una serie de aproximadamente 4 horas; los datos ya procesados los he enviado a la base de datos la caída va desde 4.65 a 4.86 magnitudes.
Lamentablemente da nubes y lluvia para los próximos días en mi latitud de España.
Last night I was able to do a set of about 4 hours; I have sent the already processed data to the database, the drop goes from 4.65 to 4.86 magnitudes. Unfortunately there are clouds and rain for the next few days at my latitude in Spain. Greetings.
Teofilo Arranz (ATE) has reported that the b Persei eclipse has begun - this is heading for the deep eclipse as the third star begins to cover and block some of the light from the much brighter A star (spec A2V) of the close binary pair. Congratulations to Teofilo!
I expect the first dip to be mostly exited by now. The mid- eclipse is expected to be during the night between Nov. 27 and 28. Hope for clear weather on both sides of the "pond" (Atlantic ocean). Shoot between the clouds if you have to.
Keep it up everyone!
Translation from spanish to English by Google Translate:
Today the 27th, at 9 p.m. I have been able to measure for an hour, it is still in a deep eclipse, magnitude 4.95. Greetings. The announced clouds arrived.
Too bad that the…
Too bad that the clouds arrived. I have good weather in SE USA but it is not dark until about 7:00 pm (12 midnight) UT.
Lástima que llegaron las nubes. Tengo buen clima en el sudeste de EE. UU., pero no oscurece hasta aproximadamente las 7:00 p. m. (12 de la medianoche) UT.
Don (translated by Google)
Hello b Per observers. We are a little ways past (1900 UT on Nov. 28 = Nov 28.8). The expected mid-eclipse time was Nov 28.3 UT. We expect the onset of another major dip in the light curve tonight - the night of Nov. 28-29. We all hope for the clouds to disperse and open up.
There is a possibility of another small dip - from a grazing eclipse - the next night (Nov. 28-29 UT), so keep on observing for several more days.
Hola b Per observadores. Estamos un poco lejos (1900 UT del 28 de noviembre = 28.8 de noviembre). La hora prevista para la mitad del eclipse era el 28.3 de noviembre UT. Esperamos el inicio de otra caída importante en la curva de luz esta noche, la noche del 28 y 29 de noviembre. Todos esperamos que las nubes se dispersen y se abran.
Existe la posibilidad de otra pequeña caída, debido a un eclipse rasante, la noche siguiente (28-29 de noviembre UT), así que continúe observando durante varios días más.
Apart from a few…
Hi there !
Apart from a few minutes around 6pm local time, the sky was overcast during the evening. But it cleared later, and I could get a full night of observations thereafter.
No hope for the 3 coming nights.
Data will be uploaded by the end of the week.
b Per was still in eclipse (and fading further) this morning (Nov 29, 03-06 UT)!
Unfortunately, heavy cloud cover prevented any observations in between (Nov 27, 28 UT).
I got about 10 hours of data last night. Prelim analysis shows it reached minimum at JD2460277.84 V~4.77
I had some problems with frost on parts of the ccd. By moving the star and comparison out of the frost (by moving scope) after pier-flip, I will be able to correct for the frost effects. This will take a while, but I'll post later.
There is another possible small dip expected at about 0000 hrs UT tonight (Nov. 30.0 UT). This "event" will be quite important if we can confirm it happening or confirm it not happening. It depends critically on the distance between the two inner stars of the system, the size of the smaller of the two stars, and the time of mid-eclipse - all parameters that we hope to narrow down their precision. If your weather permits, please try to get data!!!
Many thanks for all the dedication observers have shown during this campaign! Good work!
Looks like my V mags from last night confirmed minimum at ~2460277.834 at ~4.73.
Will be nice to see your data on LCG2.
edit: Caught it in R and I as well? Probably in B but noisier there?
PS: Mostly cloudy tonight? ;-(
I obtained about 6 1/2 hrs of data last night (JD ...278) which were terminated by increasing clouds. A small dip can be seen (the dip is less than the noise). The dip is centered on JD ...278.6 extending from 278.55 to 278.65 and followed by excessive noise from clouds. We cannot say that this dip is "real" unless we have confirmation form other observers.
I thank again all the observers who contributed data, and I thank in advance those observers who are still processing their data. Please continue to observe the out-of-eclise when weather permits, even if you did not observe any eclipse. The out-of-eclipse data are also very important to define the "ellipsoidal base line".
I will post a summary LC and simulation after I download the data and adjust for the various baselines for ellipsoid out-of-eclipse variations. Please stay tuned...
Please inform through this forum when you have posted any more data.
I can confirm the dip. I used stacking of 30 V images to smooth/improve uncertainty. See plot on LCG2.
PS: Your diffuser certainly helps smooth time series. I can't get such small noise but the same trend is obvious. ;-)