V730 Cep monitoring - Alert Notice 797

American Association of Variable Star Observers (AAVSO)
Fri, 10/28/2022 - 21:18

AAVSO Alert Notice 797 announces an observing campaign on the YSO V730 Cep. Please see the notice for details and observing instructions.

There are threads for this campaign under the following AAVSO forums:

- Campaigns and Observation Reports: https://www.aavso.org/v-730-cep-monitoring
- Young Stellar Objects (YSO): https://www.aavso.org/v-730-cep-monitoring-01

Please subscribe to these threads if you are participating in the campaign so you can be updated. Join in the discussion or ask questions there!

Many thanks, and Good observing,

Elizabeth O. Waagen, AAVSO HQ

Vereniging Voor Sterrenkunde, Werkgroep Veranderlijke Sterren (Belgium) (VVS)
V730 Mon?

I think this is an mistake in the Alert? V730 mon instead of Cep?


The most recent observations in the AAVSO International Database showed V730 Mon at visual magnitudes 14.6 on 2022 October 24.936 UT (G. Poyner, Birmingham, UK) and 15.3 on 2022 October 28.7354 UT (M. Poxon, Great Plumstead, Norfolk, UK).

American Association of Variable Star Observers (AAVSO)
Alert Notice corrected

Thanks, Hubert. Yes, I made a typo in Alert Notice 797 - the most recent observations cited are indeed V730 Cep, not V730 Mon! My sincere apologies to all.

Good observing,


American Association of Variable Star Observers (AAVSO)
V730 Cep monitoring

     Just wondering if the rationale for observing this star could be made more specific and prescriptive.  Just what does the 'wide' wavelength coverage provide in terms of the physical state of the star?  My feeling from the literature is that BVRI (say) is not especially useful --- okay, V and maybe I, but not all four are necessary.  Given that it's an early-B star, the sharp dimming is presumably related to changes in accretion and/or obscuration by a disc or something, so you'd want data relevant to that.  Thus across the visible one might prefer to have U (or Sloan u) photometry to look at Balmer continuum emission, and some sort of measurement of H-alpha as either narrowband photometry or spectra.  Accretion diagnostics from near-IR spectra are surely mainly preferred.

     I note there is a lot of photometric coverage of this field in the ASAS-SN database, and surely one could get additional data from ZTF and other on-going surveys in multiple filters.  It seems one would want to assess those sources to help decide what needs to be done to complement them.