Whitby & District Astronomical Society

Comets

Comet 2019Y4 (ATLAS)

It was hoped that a comet would unexpectedly grace our skies this month.  The comet in question Comet 2019 Y4 (ATLAS) was discovered by the Asteroid Terrestrial impact Last Alert System, based in Hawaii, last December shining at a barely scientific newsworthy magnitude of +19.  During February and March however Atlas brightened incredibly rapidly, reaching +6.8 by late March.

Now, as all amateur astronomers know predicting the brightness of a comet is like nailing jelly to a wall whilst riding a horse in the grand national (virtual horse of course) If the comet had continued to brighten at the same rate, bearing in mind it was not due to reach perihelion until the end of May, estimates for the comet’s brightness at this time ranged from an impressive magnitude -5, (in which case the comet would be visible in the bright twilight evening sky) to +2, still quite respectable.

Well, all of the above was initially penned in hope a couple of weeks ago, since then the ‘jelly’ has hit the floor and Comet Atlas has fragmented into several pieces and very likely to disintegrate into obscurity as it heads closer to the Sun............but

Comet C/2020 F8 SWAN

But hold on a minute, another comet has suddenly popped up on the radar, just as comet Atlas began to fall apart. 

Comet Swan (C/2020 F8) was discovered from data from NASA's Solar and Heliospheric Observatory (SOHO), it was spotted with SOHO's Solar Wind ANisotropies instrument (SWAN) even though it wasn't designed to find comets, but hydrogen.

The comet is small (like ATLAS) and is unlikely to be ‘eye catching’, but you never know with comets, ‘like cats they have tails and usually do what they want’.

Comet Swan will make its closest pass to Earth on May 12, coming within 51.7 million miles, before reaching its closest point to the sun, perihelion, on May 27^th.  Currently comet Swan resides South of the equator in the constellation of Sculptor, but it is heading northwards and if it continues to brighten at its present pace, it could then become visible to the naked eye from our latitude from the 22^nd onwards.  Comet Swan will then be passing up through the upper left hand side of Perseus heading toward bright Capella in Auriga for early June.  You will need to view low in the NNW sky around 22:45h and/or low in the NNE around 03:00h.  It is unfortunately the brightest part of the sky at this time of year.

 As of going to press a cautionary note has to be struck as the latest data /images suggest like Comet Atlas, comet Swan may also disintegrate and fade.  Comets ...do my head in!

Meteors

If you are a very early riser, look out for some shooting stars around May 5/6/7^th, when the Eta Aquarid meteor shower reaches a peak. 

The shower actually peaks on the evening of the 5^th, but as Aquarius rises in the early morning hours at this time of year, the morning of the 6^th will be the optimum time to view.  Observations will be somewhat hampered by light from a waxing Moon, being just two days off Full, it will however be dropping lower into the west by that time.

This is one of two meteor showers associated with debris particles deposited over time by comet Halley, the other shower being the Orionids seen in late October.

Eta Aquarids have a ZHR (zenith hourly rate) approaching 30, conditions this year will restrict numbers to perhaps 9-12 per hour.  The radiant of the shower lies close to eta Aquarius, one of the stars making up the "water jar" in the otherwise faint constellation of Aquarius.  View around 04:00h to the South, East or higher to the Southeast.

Looking North Mid-May - 22:30h	Looking South Mid-May - 22:30h
Looking East Mid-May - 22:30h	Looking West ​Mid-May - 22:30h
Northern Aspect ​Mid-May - 22:30h	Southern Aspect ​Mid-May - 22:30h
Looking North (Early) ​Mid-May - 03:30h	Looking South (Early) ​Mid-May - 03:30h