New Binocular Nova Cas 2021 Flares in Cassiopeia – Today

A ‘new star’ erupted into visibility over the previous weekend, and continues to brighten.

It started, as all trendy astronomical alerts appear to, with one tweet, then two. Early on the morning of Friday, March 19th, we began seeing phrase {that a} nova was noticed within the constellation of Cassiopeia the Queen, close to its border with Cepheus. On the time, the nova was at magnitude +10 ‘with a bullet,’ and nonetheless brightening. A proper discover got here that very same evening from the American Affiliation of Variable Star Observers (AAVSO) with Alert Notice 735 on the invention of the primary nova in Cassiopeia for 2021, Nova Cassiopeiae 2021, or N Cas 2021.

The invention was made by Japanese observer Yuji Nakamura on the evening of March 18th, 2021, and the newly seen star had an preliminary brightness of +9.6.

Present visibility: Will Nova Cassiopeiae 2021 proceed to brighten?

As of penning this, N Cas 2021 continues to be brightening at round magnitude +7. That places it in simple vary of binoculars, and if it brightens rather more, it’ll be inside bare eye visibility from a darkish sky web site.

In late March, Cassiopeia is low to the northwest for northern hemisphere observers at nightfall, sinking in direction of decrease end result close to native earlier than gaining elevation to the northeast within the early daybreak hours. The Moon is now waxing in direction of Full on March 28th , after which, it should wane and start to go away the nightfall scene.

The +5th magnitude star four Cassiopeiae is close by, making a very good star. One other acquainted deep sky goal is simply over half a level from Nova Cas 2021, the +6.9 magnitude open cluster Messier 52. Nova Cas 2021 is roughly equidistant between the bare eye Beta Cassiopeiae and Iota Cephei.

A widefield finder chart for Nova Cas 2021. The pink inset is the sphere for the close-in chart (beneath) Credit score: Dave Dickinson/Stellarium.

The coordinates for Nova Cas 2021 are Proper Ascension (R.A.) 23 Hours 24 minutes and 48 seconds, Declination +61 levels 11 minutes and 15 seconds. Star hop by the sphere and evaluate the nova with close by stars of identified brightness to search out the nova and gauge its magnitude. You can also make your individual customized finder charts for Nova Cas 2021 on the AAVSO website.

A ‘true ’ (versus inverted) 10 diploma finder chart, centered on Nova Cas 2021. Credit score: The AAVSO

This specific nova is a couple of diploma off of the galactic , a regular area alongside which novae usually seem. Classical novae when a white dwarf orbits a most important sequence star in a decent embrace, drawing in materials which then accretes or concentrates across the white dwarf. The fabric then compresses across the white dwarf, heats up, and ultimately ignites in a runaway fusion course of. A sub-category of repeating eruptive variable stars are often known as cataclysmic or recurrent novae. T Pyxidis and U Scorpii are good examples of this subclass.

An artist’s conception of a nova within the act of formation. NASA/CXC/M. Weiss

The distance to Nova Cas 2021 isn’t but identified, however most of those are likely to peak round an absolute magnitude of -Eight and—like extra-galactic supernovae—maintain promise to be used as customary candles to measure distance. ‘If’ +7th magnitude is the height for Nova Cas 2021, that will counsel it’s about 30,000 to 32,000 light-years distant, out on the fringe of the Outer Arm of the Milky Means Galaxy, simply past the Perseus Arm… but when it brightens, it might be significantly nearer.

The final good bare eye nova for the northern hemisphere was Nova Delphini 2013 within the tiny cetacean constellation of Delphinus the Dolphin about eight years in the past. On common, we get a very good bare eye galactic nova about roughly as soon as per decade or so.

Right here’s our record of novae noticed over the previous century:

20th and 21st century bare eye novae. Tailored from our newest Deep-Sky Field Guide. Credit score: Dave Dickinson

If the patch of sky presently internet hosting Nova Cas 2021 appears acquainted, it is likely to be as a result of it’s solely six levels from the location of Tycho’s supernova, famous by astronomer Tycho Brahe in 1572.

Tycho’s Star, seen in 1572. Wikimedia Commons/Public Area.

Sadly, galactic supernovae are a lot rarer cosmic beasts. Although we see a number of per yr in distant galaxies, we haven’t had a very good one in our personal galactic neighborhood for the reason that introduction of telescopic astronomy, 4 centuries in the past. Spica (Alpha Virginis) and Betelgeuse are good close by candidates, although each are far past the 50 light-year ‘kill zone,’ and can merely placed on a very good present. Betelgeuse gave us all pause in late 2019 by early 2020 when it dimmed markedly, however appears to be again to its outdated self, for now.

If skies are clear, you’ll want to observe down Nova Cas 2021 tonight… it would simply be the ‘cosmic nova present’ for this decade.

Lead picture: Now you see it… Nova Cas 2021. Picture Credit score and copyright: Mary McIntyre



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