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Constellations seem spilled from heaven’s jewel box

Power outages caused by Hurricane Fiona cut light pollution for great night sky viewing

GLENN ROBERTS glennkroberts@gmail.com @chronicleherald Glenn K. Roberts lives in Stratford, P.E.I., and has been an avid amateur astronomer since he was a small child. He welcomes comments from readers at glennkroberts@ gmail.com

It is truly amazing how clear the night sky can be at times. Not to diminish the severity of the property damage and loss associated with last week’s Hurricane Fiona, which struck the Atlantic provinces with such ferocity, it was, nonetheless, absolutely amazing how crystal clear the night sky was on Saturday night, once the hurricane had more or less moved away.

Around midnight, I stepped outside to check the weather and, there above me, stretched the Milky Way in all its splendour and beauty. The stars shone with astonishing brilliance and many of the fainter constellations and star clusters dazzled my eyes.

Of course, the horizon-tohorizon total darkness, the result of the province-wide power blackout due to the passage of Fiona, enabled this extraordinary view. I would estimate that it was definitely a 1 on the Bortle scale, with no light pollution whatsoever, a sight here in the Charlottetown-stratford urban area that has not been seen since the lights across Prince Edward Island went out due to Hurricane Dorian in Sept. 2019.

Racing back indoors, I stumbled around in the dark (my power, as elsewhere, was out) until I located my 10 x 50 binoculars (I contemplated setting up my 12” Meade SCT, but decided not to, as it would have taken at least an hour to get it set up, focused and cooled).

Settling in a lounge chair on my deck, I lay back, focused the binoculars and swept the

heavens. Directly above me shone the constellations of

Cassiopeia — the Queen and Perseus — the Prince.

Scanning both these constellations, my eyes were captivated by the sight of the Double Cluster (sometimes referred to as the Double Cluster in Perseus), two sideby-side open star clusters located between the Queen and the Prince. While readily spotted with the naked eye on a clear, moonless night (even from a suburban area), viewing them in binoculars is breathtaking. Zeroing in on each star cluster with a telescope, though narrowing the view, brings a rich collection of bright stars into focus.

As many times as I have observed these two clusters, I still imagine them as diamonds spilled from a celestial jewel box onto black velvet.

The double star clusters are composed of the clusters NGC 869 (to the west) and NGC 884 (to the east). The New General Catalogue (NGC) is a list of deep sky objects compiled by John Louis Emil Dreyer in 1888 (an update to John Herschel’s catalogue). NGC 869, located about 7,000 light years from Earth, shines at +5.0 mag., whereas NGC 884, located around 8,000 light years away, shines at +6.0 mag.

Both clusters contain more than 300 hundred blue-white supergiant stars, with a handful of orange supergiant stars mixed in. The clusters are both estimated to be between 12.8 and 14 million years old.

NGC 884, though less dense than its western companion, contains two +8 and +9 mag. triangular groupings of stars, which can be readily identified in binoculars and scopes.

Visible in the autumn and winter night sky, these two magnificent open-star clusters are definitely something you should have on your to-see list of celestial objects. Try first locating them with your unaided eye on a clear night away from city lights and then view them with binoculars or a telescope. I am sure you will agree with me that they are true celestial diamonds.

IN THE SKY THIS WEEK

Saturn (mag. +0.5, in Capricornus — the Sea Goat) is visible 19 degrees above the southeast horizon around 7 p.m., as dusk gives way to darkness, reaching 27 degrees above the southern horizon around 9:45 p.m. and remaining observable until about 1:25 a.m., when it sinks below 10 degrees above the southwest horizon.

On the 5th, look for Saturn four degrees north of the moon.

Jupiter (mag. -2.9, in Pisces — the Fish) is visible by about 7:25 p.m. when it reaches seven degrees above the eastern horizon. It reaches its highest point in the night sky around 12:35 a.m., 43 degrees above the southern horizon, before becoming inaccessible when it drops below seven degrees above the western horizon around 5:50 a.m.

Mars (mag. -0.5, in Taurus — the |Bull) becomes visible eight degrees above the northeast horizon by 11 p.m., achieving a height of 66 degrees above the southern horizon around 5 :45 a.m. and then becoming lost in the dawn twilight 62 degrees above the southwest horizon by about 6:50 a.m.

Both Venus and Mercury are too close to the sun to be observable.

The full moon on Oct. 9 is still often referred to as the Hunter’s Moon, after the ageold practice (now illegal) of hunters pursuing their prey by the light of the full moon in October.

Until next week, clear skies.

Science

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2022-10-04T07:00:00.0000000Z

2022-10-04T07:00:00.0000000Z

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