- This topic has 3 replies, 3 voices, and was last updated 2 weeks ago by
.
-
Posts
-
A perhaps slightly crazy idea has occurred.
When T CrB goes off, the rise to maximum is likely to take only a few hours. For the time being it is inconveniently close to the sun and so is only at a high altitude and low airmass during daylight.
I know that bright stars are easy to image in daylight. With my scope substantially sub-second exposures through a Sloane r’ or i’ filter show stars down to at least 9th magnitude, though at rather low contrast. (Near-IR imaging isn’t strictly necessary but the daytime sky is readily seen to be blue, not red, and so is much darker through those filters, or Cousins-R and Tri-colour R for that matter). Proof is provided at https://stargazerslounge.com/topic/421791-messier-objects-by-daylight/#comment-4483343
Given that T CrB is around 10th magnitude at present it should be relatively easy to image in the day time. The main problem will be putting it in the field of view unless your mount has good absolute positioning. After that, take images at a range of exposures until the star is just about saturated or slightly less and the sky is not saturated. Bring the contrast right up by subtracting the mean or median sky brightness from the image and what is left is a clear star in a noisy background.
Of course, once T CrB does go into outburst that fact will be very obvious and it is time to send out an immediate alert so that the rise to maximum can be monitored.
Anyone willing to have a try? I can’t until January when I return to the observatory in La Palma.
This is definitely feasible. Arne Henden is routinely monitoring T CrB in daylight. He is using a Newtonian stopped down to 50mm and is able to image theta CrB mag ~4.1. The other day there was a false alarm and he was able to show that there was nothing brighter than mag ~4.5.
The rise time is 1-5 hours.
At this time of year, a 24h coverage would be possible again just with night observations if there were enough observers around the planet. If I look at the AAVSO database, there are calendar days when we have up to ca 50% coverage: after someone in Europe observes for most of the night, someone in the US takes over … and then we get a gap.
I wonder if there are actually no active T CrB observers in that longitude range? Perhaps there are observers who just don’t bother to submit the data in the absence of an outbreak?
Imagine what it would be like to catch the actual nova outbreak in a high cadence photometry data set! I don’t think this has ever been done for a nova this close.
E.g. there must be tons of Seestar smart telescopes in China that could join the T CrB watch and help close the observation gap. How can we reach out to them?
Cheers
HBEThere is something of a gap in coverage at Pacific longitudes. Partly due to sparsely populated regions and partly due to people submitting their observations to other organisations (e.g. Japan). The Philippines seems to be a fruitful area for increasing coverage.
Keep up the good work with your imaging patrol.
- You must be logged in to reply to this topic.