AAVSO: American Association of Variable Star Observers
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Proposal #83

Proposer (15617) John Martin (jmart5@uis.edu) obscode: UIS01
Assigned To(3663) Dirk Terrell
Date SubmittedMarch 18, 2018
StatusAccepted
PriorityNormal
Proposal

Monitoring of V1427 Aql (HD 179821). Sahin et al (2016MNRAS.461.4071S) makes a convincing argument through detailed abundance analysis that V1427 is a warm hyper giant similar to Rho Cas. The AAVSO IAD contains only visual observations for this target from 2002 to the present. Arkhipova et al. (2009AstL...35..764A) published UBV photometry between 2000--2008 (http://vizier.cfa.harvard.edu/viz-bin/vizExec/Vgraph?J/PAZh/35/846/./table1&) showing low amplitude irregular variability with periods from 130--200 days.
If V1427 Aql is a massive warm hyper giant and potential near-term supernova candidate then continued monitoring and characterization of its variability could pay important dividends for understanding the post-main sequence evolution of the most massive stars. Alternatively if it is a very luminous PAGB star, that also makes it very astrophysically interesting as an extreme example of the PAGB class that is not easily explained by current stellar models.
Following up to the monitoring by Arkipova et al. a decade earlier will verify their work and may also detect evolutionary changes.
We propose standard weekly monitoring in Johnson B and Johnson V by the BSM network for the indefinite future (at least several years to match the Arkhipova light curve sampling). We waive the proprietary period and plan to immediately submit all photometry gathered to the IAD as soon as it is reduced as a service to the astrophysical community.
The source for the RA and Dec is the Gaia DR1 release. The source for the magnitude range is VSX.

Targets
Target RA (H.HH) Dec (D.DD) Magnitude Telescope Observation Frequency Expiration Date Proprietary Term
V1427 Aql 19.232947 0.12554 7.82–8.24 No

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