#astronomy New nova in Cassiopeia brightens quickly – Astronomy Now

March 21, 2021 - Comment

Nova Cas 2021 imaged from Nayro Hokkaido, Japan, on 19 March (2021 03 19.696) shining at round magnitude +7.49. Picture: Yasuo Sano. There’s a ‘new star’ – a classical nova – on present among the many stars of the far-northern constellation of Cassiopeia. Nova Cas 2021 was found on 18 March shining at round magnitude



Nova Cas 2021 imaged from Nayro Hokkaido, Japan, on 19 March (2021 03 19.696) shining at round magnitude +7.49. Picture: Yasuo Sano.

There’s a ‘new star’ – a classical nova – on present among the many stars of the far-northern constellation of Cassiopeia. Nova Cas 2021 was found on 18 March shining at round magnitude +9.6, however it seems to have brightened quickly to round magnitude +7.5 on 19 March.

Nova Cas 2021 must be seen by means of a pair of 10 x 50 binoculars or a small telescope on the exact place RA 23h 24m 47.73s, Dec +61° 11’ 14.Eight” (J2000.zero). It’s handily positioned, mendacity simply 2.5 arcminutes north-east of the magnitude +Eight.9 star HIP 115566 (SAO 20610), which itself is situated a 24-arcminute hop to the south of the brilliant open star cluster Messier 52 (NGC 7654).

Nova Cas 2021 lies within the north-western area of Cassiopeia, round 5.Four levels north-west of magnitude +2.three Caph (beta Cassiopeia), the westernmost mendacity of the 5 brilliant stars forming Cassiopeia’s acquainted ‘W’ asterism (star sample). The nova lies round 24 arcminutes south of the brilliant (magnitude +6.9) open star cluster Messier 52 (NGC 7654). AN Graphic by Greg Smye-Rumsby.

Cassiopeia is circumpolar (by no means units) from UK shores; as quickly as darkness falls between about 7.30pm and seven.45pm GMT, the placement round M52 lies some 33 to 37 levels above the north-western horizon. Over the course of the night the constellation descends in the direction of the horizon, reaching its lowest level due north shortly earlier than midnight. By the point skies begin to lighten with the onset of nautical twilight (when the Solar lies between 12 and 6 levels under the horizon) at about Four.45am GMT, Nova Cas 2021 can have climbed to an altitude of round 40 levels above the north-north-eastern horizon.

The 30×20 arcminute subject exhibits the place of Nova Cas 2021, with magnitude +Eight.97 HIP 115566 (SAO 20610) mendacity round 2.5 arcminutes to the south-west. North is up, with east to the left.

Nova Cas 2021 was found by Yuji Nakamura of Japan on 18 March at about 10h UT, when it shone at round magnitude +9.6. He shot 4 15-second frames with a 135mm, f/Four lens coupled to a CCD digital camera (a set-up which supplied a limiting magnitude of +12) and additional reported that no object was seen on the transient object’s place on frames shot with the identical gear on 14 March.

Simply hours later, skilled astronomers from the Nationwide Astronomical Observatory of Japan swung into motion, acquiring a spectrum of the item with the three.Eight-m Seimei Telescope at Okayama Observatory and photometry by means of a zero.Four-m telescope at Kyoto College. The spectrum revealed the inform story options of a classical nova, with emission traces of the Balmer collection, N-III 4640 and He-II 4686, and He-I emission traces with P-Cyg profiles. They additional discovered and recognized traces N-II 5679, C-III 5695 and Paschen emission traces. The place of Nova Cas 2021 exactly coincides with that of the W UMa-type eclipsing variable star CzeV3217, which lies at a distance of about 5,500 mild years.

Nova Cas 2021 imaged from Katori, Japan, on 19 March (2021 03 19.46809) shining at round magnitude +7.Eight. The intense star to the south-west (decrease proper) is HIP 115566 (SAO 20610), which has a catalogued magnitude of +Eight.97. The nova is clearly brighter. Picture: T. Noguchi.

Novae are short-lived outbursts from aged binary star methods involving gasoline piling up onto a white dwarf from a companion star, igniting a thermonuclear response on the white dwarf and an explosion on its floor that’s violent sufficient to be seen throughout the Galaxy. We see the sudden look of a ‘new’ (nova is Latin for ‘new’) star.

The behaviour of many novae is notoriously unpredictable and so observations of Nova Cas 2021 are extremely inspired, particularly because it seems to have been found at an early stage.

For observers who want to make estimates of the nova’s brightness to assemble a light-curve, take a look at this chart and sequence from the AAVSO. A spectrum of the nova might be seen right here http://www.kusastro.kyoto-u.ac.jp/~kentagch/atel/pnvj2324.pdf

There’s extra detailed info out there at Astronomer’s Telegram, and on the Central Bureau for Astronomical Telegrams.



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