Strange Quarks

I started observing the constellation of Corona Borealis (CrB) again this week, in preparation for the recurrent nova T CrB (aka The Blaze Star) to erupt. This was the first time I’ve done so since early October 2024, when the constellation left Adelaide’s evening sky.

On February 20th from around 5:15am, I spent 45 minutes or so reacquainting myself with the region through hand-held 7×50 binoculars, reminding myself of the comparison stars I’ll use to estimate the change in brightness of the nova, and the asterisms that will help me remember where they are.

Even pre-eruption, T CrB is observable in a small telescope at around magnitude 10, but from suburban skies, anything fainter than magnitude 6.5 or 7 is difficult through 7×50 binoculars, especially when twilight approaches. Still, it’s perfectly good enough to be able to say whether the nova event has happened.

As a reminder, the nova was anticipated before the end of 2024, but nature doesn’t always cooperate with our expectations. When the eruption does happen, T CrB will be visible without the aid of binoculars or telescopes, as bright as alpha CrB aka Alphecca (see the image below).

Why start observing it again now? For two reasons.

• That part of the sky is observable from here again, even if at 5am.
• There is recent evidence from spectroscopic observations that the rate of accretion of material around the white dwarf from the “donor” star in the pair that makes up T CrB (or any nova system) is significantly increasing. Such an increase, if it’s happening, may be a sign that the thermonuclear runaway is close.

Even so, there is not universal agreement that this result implies the nova is imminent.

Given Murphy’s Law, it will be entirely possible to miss the initial brightening, since observing 2 or 3 times a night (as I was doing last year for awhile) is not so easy in the wee hours, given the need to sleep and work, not to mention that some nights/mornings will be cloudy!

Still, it won’t stop me, and many others, from trying and in any case, the nova will be easily observable for several days either to the naked eye or with binoculars.

Here’s hoping we’ll have a bright nova (the brightest of all known recurrent novae) sometime in 2025!

This entry was posted on February 22, 2025 at 12:32 pm and is filed under Astronomy, Variable Stars. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.