Proposal #212

Eta Carinae is the most massive and luminous star in our part of the Milky Way. It's Great Eruption in the 1840s is a prototype for supernova impostors. Over the last 250 years the star has been recovering from the Great Eruption. And now, for the first time since 1860 it has almost recovered to its historic pre-eruption brightness of V = 4.0. Ten years ago the it was more difficult to measure the brightness of the star without contamination from the surrounding bright nebula. But in the last decade it has steadily grown significantly brighter than the surrounding nebula. We need to keep watching this star. It is a popular visual target but for the last couple years it has not been regularly observed in V and B. Observer BLD has measured it regularly in TG, but not in a second filter to get color information.
I am proposing only B and V coverage because Eta is one of the brightness near-infrared objects in the sky and is likely to overwhelm it in R or I. I would be interested in getting filter-wheel grating spectra for it it that is an option. Eta's spectrum has some very broad emission features that will show variability even at low spectral resolution. The bright star monitors were made for a target like this and I am happy to take it on with my other targets for service observing. All photometry obtained from the BSMs will be immediately submitted to the IAD so anyone can use it.
For the minimum and maximum magnitude I have listed the star's 300 year min and max brightness. It is currently sitting at V ~ 4.4 and (B-V) ~ 0.5. Over the last decade, short term it can fluctuates about 0.1 mag over a few weeks. Over the last 20 years it has maintained a steady long term brightening trend at a rate of 0.03 mag/year for about the last 20 years. But it could do something exciting, which is why I want someone to be keeping an eye on it.