Upcoming Visible Nova in Corona Borealis

[K^2]

On 6/28/2024 at 1:19 PM, cubinator said:

Last time this nova was observed was in 1946. Were we even doing any meaningful radio astronomy at that point? I was thinking earlier that we may not have any detailed radio observations of this nova.

I don't think we have any radio data on it. Just visual spectrum magnitude estimates. That's part of why everyone's so excited. We're going to have every instrument watching this time. We're going to get full radio data, IR and UV observations from a number of ground and space observatories, and people will be checking gravitational interferometers and neutrino detectors to see if we pick up anything in the noise that might be correlated. I don't know if we'll get the signal on the latter two that is actually measurable, but I know that neutrino fluxes from supernovas with lower apparent magnitude have been picked up. So if neutrino flux and visual brightness are anything at all close to proportional, I think we'll get something. Gravitational I'm much less optimistic about, but maybe there's clever filtering people can do based on timing correlations? It'll be interesting to see what we get either way.

At a minimum, I suspect we'll have a much refined estimate on the star's mass based on what we measure. And that might give us a better model for estimating the period of these events based on composition and proximity of the binary, letting us extend that measurement to more distant novas and possibly use them as a yet another candle. Since measuring intergalactic distances is still a pain, this might be useful to correlate with at least some nearby galaxies, and that could have ripples to the rest of the ladder.

[cubinator]

https://www.aavso.org/t-crb-time-sensitive-alerts-forum-thread

I know I'll be posting about it here as soon as I see it, but the initial call to action will likely come on this AAVSO forum thread.

[peewee69]

I could be wrong, but I think I saw the nova a few hours ago, about 10.30 BST. Initially thought maybe aircraft landing lights when I caught a passing glimpse, but later at home there was a bright and very twinkly star to the west. Stellarium points to the correct region. No news yet...

[cubinator]

28 minutes ago, peewee69 said:

I could be wrong, but I think I saw the nova a few hours ago, about 10.30 BST. Initially thought maybe aircraft landing lights when I caught a passing glimpse, but later at home there was a bright and very twinkly star to the west. Stellarium points to the correct region. No news yet...

I don't think I can check tonight as it's cloudy. However I don't see any post on the AAVSO forum, and no alert notice, and it's been dark for a little while in much of the US. We'll have to see.

There should be two twinkly stars in the same area, one being the normal brightest star in CrB and the other being the nova.

The REALLY bright, red, twinkly star in the west right now is Arcturus. If the nova were that bright, it would be a supernova and we'd have gotten a neutrino burst. I also don't think the nova will look red.

Edited August 5 by cubinator

[cubinator]

1 hour ago, peewee69 said:

I could be wrong, but I think I saw the nova a few hours ago, about 10.30 BST. Initially thought maybe aircraft landing lights when I caught a passing glimpse, but later at home there was a bright and very twinkly star to the west. Stellarium points to the correct region. No news yet...

Update: I caught a break in the clouds and checked with my binoculars. I definitely don't see the nova.

[peewee69]

Thanks for checking, I've no idea what I did see last night then. It moved with the background stars, so fairly sure it wasn't something in our atmosphere, but it clearly wasn't a normal star.

[cubinator]

5 hours ago, peewee69 said:

Thanks for checking, I've no idea what I did see last night then. It moved with the background stars, so fairly sure it wasn't something in our atmosphere, but it clearly wasn't a normal star.

The really bright red star in that general direction right now is Arcturus. If I were to catch a passing glimpse of the western sky after dusk, I'd see that star before any other. I can't confirm what you saw, though.

[peewee69]

2 hours ago, cubinator said:

The really bright red star in that general direction right now is Arcturus. If I were to catch a passing glimpse of the western sky after dusk, I'd see that star before any other. I can't confirm what you saw, though.

Yeah, I'm also thinking Arcturus. Hopefully I'll get a good look at it again tonight. Dunno how I've never noticed it before, I don't get to see many stars due to light pollution over London, but last night it appeared so bright

[Gargamel]

As cool as this is, I’m just waiting for Betelgeuse to blow, hopefully in the fall or spring.    That way we get it daytime and nighttime.   

[K^2]

18 hours ago, cubinator said:

I also don't think the nova will look red.

Definitely not early on. The surface of the white dwarf is already too hot to glow red, and certainly wouldn't get any cooler in the nova. Of course, most of the light will be produced by the cloud of the debris that is expanding, and that will cool over the several days, maintaining the brightness, for a bit, by the simple virtue of getting a larger and larger cross-section area to radiate from. What I don't know and haven't seen references to is how much it will cool before it stops being visible to the naked eye, so I don't know if we'll see a color starting to shift a few days in or if it will become too dim to see long before that.