astronomy – A Darker View

A Changing Sky

Gazing up at the sky while reading the old texts one would not be amiss in believing that the stars never change. Indeed there are many who insist vehemently that the stars are eternal and unchanging. But the stars do indeed change, often quite visibly, sometimes within the span of a human lifetime.

VLT/SPHERE image of the star L2 Puppis and its surroundings — A VLT/SPHERE image of L² Puppis showing the enveloping cloud of gas and dust representing an early stage planetary nebula. Image credit ESO/P. Kervella used under Creative Commons 4.0

One such star is L₂ Puppis.

A bright star, one of the few naked eye variable stars that could be seen to fade and reappear without the aid of a telescope much like the far more famous stars Mira and Algol. On star charts the star is found prominently drawn at magnitude 4, buf if you attempt to locate it today you will not find it without the use of a telescope.

I first encountered this star quite recently while starhopping through southern Puppis with an 8″ telescope from the driveway. The chart showed two bright stars close together, L₁ Pup and L₂ Pup, while the view in the finder ‘scope showed only one bright star.

Segment Exchange

Lifting segment 4-76 out of the Keck 2 primary mirror for re-coating and repair — Lifting segment 4-75 out of the Keck 2 primary mirror for re-coating and repair

Of Green Stars…

Wandering the sky using a telescope and a field guide published in 1844, the better part of two centuries ago, is… uhhm… interesting. In mid-April the classic winter constellations are dissapearing into the sunset, with constellations like Monocerus and Puppis well placed for observing from my driveway just after dark. On my observing table is a reprint of that 1844 field guide, The Bedford Cycle.

Working through the entries I come to the entry for a double star Argo Navis 72 P. VIII, a designation from a very old catalog. It takes a few moments research to convert 72 P. VIII to the slightly more modern catalog number HD 71176. Modern? The Henry Draper Catalog was first published by Harvard Observatory in 1918, still over a century ago.

With the HD number I can look up the position on a modern chart and spend a few moments star-hopping the Astrola to the correct star. This double star is now located in the constellation Puppis after the ancient and absurdly large constellation Argo Navis was broken up into Puppis, Vela, and Carina.

Waiting for Dark

Awaiting dark with the 20" telescope — Andrew Unger beside the 20″ Obsession while waiting for properly dark skies at Kaʻohe

A View from the Past

As an evening pastime in these COVID restricted days I have been delving into the past again. Again reading the work of an amateur astronomer from long ago.

Frontspiece of Bedford Catalogue, 1844, Capt. William Henry Smyth

I had previously read through the work of Rev. Thomas Webb, a vicar and amateur astronomer active in the late 1800’s. Webb frequently refers to the work of a yet earlier observer, Capt. William Henry Smyth.

Retired British Navy Captain Smyth was a backyard observer, gazing at the stars with a 150mm refractor from a garden behind his home in Bedford England. His telescope was quite good for the time, made by Tully of London, the best money could buy. This telescope was eventually purchased by the British Government to be used in the 1874 transit of Venus expedition to Egypt and the 1882 Venus transit in Jamaica. It now sits in the collection of the Science Museum, London.

Capt. William Henry Smyth's Telescope at Bedford — Capt. William Henry Smyth’s Telescope at Bedford

Smyth published two volumes on astronomy in 1844 under the title A Cycle of Celestial Objects . Volume II of this set, commonly called The Bedford Catalogue or The Bedford Cycle, contains descriptions of more than 850 double stars, clusters, and nebulae, serving as a guide to what may be observed with a small telescope. The Bedford Catalogue became the standard at-the-telescope reference for other amateur observers for many decades until it was generally replaced by Webb’s Objects for Common Telescopes.

Andrea Ghez awarded the Nobel Prize in Physics

UCLA scientist and Keck Observatory user Andrea Ghez has been awarded the Nobel Prize in physics. She shares the prize with two other researchers; Roger Penrose, a British mathematical physicist and German astrophysicist Reinhard Genzel, for work in black holes and galaxies.

Andrea Ghez presents a community lecture at the Honoka'a People's Theater — Andrea Ghez presents a community lecture at the Honoka’a People’s Theater

There is no Nobel prize in astronomy and the Nobel in physics has traditionally gone to scientists involved in hard physics for discoveries of some new theory or subatomic particle. It is only in recent years that we have seen a few Nobel prizes awarded to astronomers.

Andrea is the only Nobel recipient I have known personally. I can say one thing, she completely deserves it. While her scientific achievements may justify the award, her activities beyond the science are just as commendable.

Star Types

I have been observing a lot of stars during my driveway sessions at the telescope lately. Some of these are new to me, will have to look them up and hunt them down…

Eyepiece Time

Given stay at home orders and a virus haunting our community I have gotten quite a bit of eyepiece time this year. Mostly quick driveway session in the evening, or sometimes the early dawn hours, a solo activity perfect for social distancing.

I usually use my roll-out scope ready in the corner of the garage, a classic 8″ Cave Astrola. Just roll it into the driveway, plug it in using the purpose located power receptacle on the corner of the lanai,. slide an eyepiece in… Ready to go in two minutes.

Last night was a perfect example… It was raining at sunset, but an hour later the skies were clear and dark. Better yet the rain had left clear, haze free air overhead with great transparency. I spent an hour hunting down dark nebulae in Aquila, dark clouds of galactic dust best visible with perfect skies.

The pages of the observing notebook fill quickly, a page or two each evening until the Moon comes back. I have so many object I have never viewed, so many easily visible from the driveway with a fairly small 8″ ‘scope.

Often I come across pleasant surprises, a pretty binary or a deep red carbon star, the region surrounding my target rich with stars and wisps of nebulae, so many wonders I have never seen despite years at the eyepiece.

A Moonlit Night at Kaʻohe

It was Norman who started it.

The last glow of Sunset over Hualālai, with Venus just about to set behind the mauna and Jupiter high above.

An innocent email… Anyone interested in a star party this weekend?

Last weekend’s new Moon star party had been a bust, heavy clouds overhead were a disappointment to those of us waiting for a good dark night.

Given the positive response to Norman’s email there seems to be a few folks ready to go despite a bright Moon in the sky. With the weather looking good the Saturday afternoon email flurry showed that a few folks were going, thus I joined in.

As per Mauna Kea normal I drove through the clouds, heavy fog on Saddle Road just a mile from Kaʻohe made the trip seem hopeless. But as I neared the turn I suddenly found myself above the clouds, the bright Moon high over Hualalai.

In the Driveway Again

Before the Moon gets too bright, and while we have a few hours of clear skies… Shooting a few photos from the driveway with a new camera. Now if only my guiding were better, the declination was having issues, probably a bad polar alignment… What did I do wrong?