Author: Stephen Mackintosh

New Information on Betelgeuse

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Betelgeuse, shown here as the top left star in the shoulder of Orion

Some interesting new information has emerged on Betelgeuse, the red supergiant that marks the left ‘armpit’ of Orion the Hunter.

In summary:

1. It’s still burning Helium in its core so unlikely to go supernova until around 100,000 years.

2. It’s not as massive as previously thought. Earlier studies had shown its radius would extend to the orbit ofJupiter if placed in our solar system. This new data suggests its real radius is 60% of this.

3. It’s closer to Earth than previously measured, at 530 light years. This is 25% closer than we previously thought.

New data published in the Astrophysical Journal. Further reading here.

2021 Hebridean Dark Sky Festival

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I’m very much looking forward to a return to the inky dark skies over the Isle of Lewis next February for the Hebridean Dark Sky Festival. The full lineup and details are available from organisers An Lanntair.

I’ve been reminiscing about last year’s festival, when I toured Lewis delivering outreach to a collection of remote communities under some of the best dark skies you’ll find anywhere. You can read my short account from last February on my blog page here. I look forward to more of the same in 2021, travelling to some new locations on the island.

“Watch the skies! The Hebridean Dark Skies Festival is to return to the Isle of Lewis in February 2021. The two-week programme will include an exhibition by astronomy-inspired artist collective Lumen; music by Kathryn Joseph and Renzo Spiteri; talks by award-winning TV presenter Dallas Campbell and renowned climate scientist Tamsin Edwards; stargazing with Highland Astronomy; a night swim with Immerse Hebrides; and lots more to be announced. Find out more by reading our news story. Thanks to CalMac Ferries and Outer Hebrides LEADER for their continued support, and to festival partners/supporters Lews Castle College UHI, Callanish Stones & Visitor Centre, Stornoway Astronomical Society, Outer Hebrides, VisitScotland, Gallan Head Community Trust, Hebridean Hopscotch Holidays and Loganair.Please note that An Lanntair has put in place stringent systems to help mitigate risks from COVID-19 in its building and across its activities to keep staff and the public safe. Details can be found at https://lanntair.com/visit-us-safely/. A Coronavirus Risk Assessment specific to the Hebridean Dark Skies Festival will be in place for the event. Stornoway Gazettewelovestornoway.comEVENTS: what’s happening in Lewis + Harris“

Mars at Opposition

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Collage by Instagram’s @NightSkyFlying

Have you noticed the dazzling red star high in the East during late evening? That’s the planet Mars and it’s now nearing opposition on October 13th, offering some of the best naked eye and telescopic views possible.

Opposition is when Mars and Earth reach their closest approach to each other with respect to their independent orbits around the Sun. For Mars and Earth, this happens every 2 years and 2 months.

With the planet’s relatively high altitude and closeness around opposition, current views of the planet even with moderately powerful telescopes should be striking, perhaps revealing dim surface features and polar caps.

These images from Instagram’s @nightskyflying show the dramatic size and clarity change of Mars over a period of many months. If you don’t have a telescope it’s still worth looking up to appreciate the brightness of Mars as a naked eye planet at the moment.

Image by @NightSkyFlying

Signs of Microbial Life on Venus?

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All eyes are now on planet Venus, our bright morning and evening star.

In the 1950s Venus was one of the most dreamed of and speculated about planets in the solar system. Science fiction portrayed it as a swampy planet covered in rain forests and abundant with strange alien life. Then, after the Soviet Venera missions discovered the hellish conditions on the surface, interest waned somewhat and attention shifted to Mars.

With recent discoveries of Phosphine gas in the planet’s atmosphere, Venus looks set to recapture all of its human wonder and fascination.

Venus has always had the potential to harbour life high in its atmosphere. While its surface is baking hot with crushing pressures, its upper atmosphere is a relatively warm and clement environment.

So far we can’t imagine a natural process which could produce such high concentrations of phosphine gas in the Venus atmosphere but that doesn’t mean there isn’t an explanation that precludes life. Meanwhile we are left to speculate about the many possibilities, including the most tantalising of all, that some form of ancient anaerobic microbial life exists, or has existed, within Venus’s upper atmosphere.

Watch a Supernova Explosion in a Distant Galaxy

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See a supernova explosion in a distant galaxy over 50 million light years away.

Berto Monard witnessed Supernova 2015F in spiral galaxy NGC 2442 in March 2015, although the actual event happened 50 million years ago, long before human beings inhabited planet Earth.

Supernovae like this produce so much light energy they can briefly out shine the accumulated light from the entire galaxy. For this reason they can be witnessed even with moderately sized back garden telescopes, if you’re lucky enough to be pointing in the right direction at the right time!

Video Credit & Copyright: Changsu Choi & Myungshin Im (Seoul National University)
Source: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)

Milky Way Images

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The Milky Way over the Callanish Stones on the Isle of Lewis.  Jupiter and Saturn can be seen in this shot low above the horizon. By Emma Rennie of Callanish Digital Design.  www.callanishdigitaldesign.com

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Another stunning Milky Way shot by Christopher Cogan taken from Muie in Sutherland in the far north of Scotland.

Two stunning Milky Way images taken last night from the Scottish Highlands (and Islands). Both show the bright region of the Milky Way in the vicinity of the Summer Triangle, looking south.

If you imagine our Milky Way as a vast disk of stars, these views are peering further ‘into’ the disk, where the density of stars and stellar matter is greater, and hence brighter. Contrast this with the fainter regions we see in Winter near Orion, when we peer ‘out’ of the galactic disk.

The dark lanes you can see are part of the Cygnus Rift – a region containing vast clouds of dust that obscure some of the light from the billions of stars in the background.

With the Moon well out of the way and proper darkness returning late at night, now is a great time to go out and see the Milky Way for yourself.

The Cat’s Eye Halo

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Image Credit: R. Corradi, Nordic Optical Telescope

I recently stumbled across this stunning image of the famous Cat’s Eye nebula. It’s a false colour enhancement showing the extended ejecta from the dying star, imaged by the Nordic Optical Telescope on the Canary islands..

The cat’s eye is dubbed a ‘planetary nebula’. An erroneous label as this has nothing to do with planets whatsoever. Rather these nebulae are the beautiful symmetries left behind when stars of similar mass to our Sun enter their final gasps of life. Before collapsing down to a white dwarf (a compact star held in place by electron pressure), the star sheds its atmosphere is great puffs, producing these ghostly but beautiful clouds of ionised gas.

I made a video about Planetary nebulae you can watch here:
https://modulouniverse.com/2019/03/03/planetary-nebulae-video/

The outer gaseous tendrils seen in this image extend almost 3 light years across and probably represent earlier and more transient episodes of stellar influenza, before the star began its collapse in earnest.

Image Credit: R. Corradi, Nordic Optical Telescope