As 2019 came to a close, the news media sensationalized a story about Orion’s bright star Betelgeuse. The headlines were certainly designed to get one’s attention. Betelgeuse was about to go supernova. However, the star’s behavior was really old news that was recently enhanced by new observational data. You see, Betelgeuse is a red super giant star (20 times more massive than our Sun and approximately 1000 times larger) that is indeed nearing the end of its life cycle. And with a star this massive, the result will someday be a supernova event.
Betelgeuse is a known variable star, which pulsates back and forth about one full magnitude (brightness scale) in a 425-day period. What happened more recently is that the star dimmed a little more than usual, by about .2 of a magnitude. An imaging technique using radio waves revealed Betelgeuse appeared to be lopsided, but this discovery turned out to be a huge dust cloud blocking some of the star’s light from reaching us. In fact, Betelgeuse has shed off great shells of its outer surface several times in the past, typical activity for these stars as they “burn” through their supply of nuclear fuel. Speculation arose that Betelgeuse’s grand finale was soon at hand.
However, every article I read succinctly stated the event could happen soon, or 100,000 years from now. While it is inevitable that Betelgeuse will go supernova in the future, we needn’t worry. Fortunately, at its distance of about 700 light years from the Earth, we will not suffer from any hard radiation effects. The supernova will be at least as bright as a Full Moon and will be visible in broad daylight. About a day before we see the visible light from the supernova event our Earth will be bombarded by a harmless hail of neutrinos and gamma rays. That onslaught will be our advance warning system that Betelgeuse the star has met its demise.
Continue reading Supernova deferred (for now), Easter, and a meteor shower
A little more than ninety years ago, in a barred spiral galaxy named the Milky Way, a stellar system named Sol had a retinue of eight known planets revolving around it. The last one to be discovered was Neptune in September 1846. However, as time passed small perturbations in Neptune’s orbit were noted, which suggested another “trans-Neptunian object” existed whose presence altered his path around our Sun. It wasn’t until 1905 that a wealthy Boston astronomer, Percival Lowell, started a search for “Planet X” using his Flagstaff, Arizona, observatory. Lowell, with his mathematics background, and with the help of colleagues, tried to derive a possible orbit for a potential unknown planet. They even took photographic plates in 1906 of an area of sky where they thought planet “X” might be located, but with no results.
Percival Lowell died at age 61 on November 12, 1916 and the search for the
elusive “Planet X” ended. However,
in 1929, the search for Pluto was resumed at the Lowell Observatory using calculations
that Lowell had computed earlier. A 23 year-old Clyde W. Tombaugh was hired to meticulously
image specific areas of the sky using photographic glass plates. The
same star field would be exposed several days apart. Once the plates were
developed, they were placed in a viewing machine called a blink comparator that
held two plates. The operator could switch back and forth from one plate to the
other. This process was called “blinking.”
Continue reading Pluto at Ninety: Discovered, Demoted, Visited
When guests visit the local observatories, staff astronomers always look to impress them with great views of the Moon, Jupiter, Saturn and Mars when any of these worlds are observable. The wealth of detail visible through each facility’s telescopes can awaken the sense of awe within children and adults alike. What child hasn’t marveled at the Moon’s vast craters? Who hasn’t watched the parade of Jupiter’s Galilean moons orbiting this gigantic planet and not thought about Galileo’s first view of this phenomenal sight? We sky interpreters love to hear the oohs and aahs as folks get a glimpse of Saturn’s magnificent rings for the first time. And when dust storms on Mars don’t spoil the view of this desert-like world, who can’t help but wonder if life may exist beneath its surface? Any night amateur astronomers can introduce casual stargazers to these magnificent worlds is a wonderful experience.
However, while the afore-mentioned objects get most of the glory, there are two inferior planets of our solar system that are often neglected. No, they do not have any neuroses. Inferior is an astronomical term meaning these planets orbit between the Sun and the Earth. I’m referring to Mercury and Venus. Consequently, they do not stray far from the Sun in the sky from our Earthly perspective. Examine this brief video which explains what we observe. Whenever Mercury and Venus appear above either the eastern or western horizon these events are called elongations. Mercury can appear no more than a maximum of 28 degrees away from the Sun, while Venus can appear no more than a maximum of 48 degrees away from the Sun. Elevation above one’s horizon varies from one elongation to another.
Continue reading Observing the Inner Solar System: Mercury and Venus
Happy New Year everyone. Yet another year has passed into the history books, and I am once again presenting some of the astronomical highlights upcoming in 2020. While there are a couple of impressive upcoming events, any time the skies are clear and transparent many stargazers are enticed out under the vault of the heavens to explore our beautiful universe.
The winter months around Southern New England
can be quite cold, and I for one need some incentive to spend much time outdoors
observing the sky. Fortunately, the sky gods provide the Quadrantid meteor
shower which peaks on the night of January 3-4. While this shooting star
display can produce up to 100 meteors per hour during peak, a more modest 60
meteors per hour is likely under a moon-less sky. This shower also sports a
very narrow peak of activity, only several hours in duration, that can easily
be missed. However, if you have the time and can tolerate the usual cold
temperatures, the Quadrantids don’t disappoint the well-prepared observer.
Continue reading Astronomical Highlights for 2020
As quickly as it started, 2019 will soon be
in the history books. I for one am happy to see it go. A cloudy and rainy
spring, hot and humid heat waves during the summer, then the EEE mosquito threat
have conspired to prevent casual stargazers and amateur astronomers alike from
enjoying the night sky and all the wonders it holds. It would be great if we
could end the year on a high note, but the sky gods are not smiling down on us
Though the Geminids are the best meteor
shower of the year, peaking on the night of December 13-14, the Full Moon on
the 12th will overwhelm all but the brightest meteors. To complicate
matters further on the peak night, that bright moon will be sitting right in
the middle of the Gemini constellation. While you won’t require my usual star map
to find Gemini, the proximity of the Moon to the region of the sky from where
the meteors appear to radiate (near Gemini’s brightest stars, Castor and Pollux),
will certainly reduce your meteor count. .
However, one does not have to look directly
at Gemini to catch a few of the brightest shooting stars. In fact, the Geminids
are fairly bright and also have a reputation for producing exploding meteors
called fireballs, My point: if the weather cooperates on peak night do not give
up on the Geminids. You might just glimpse a few bright Geminids as they enter
our atmosphere at 21.75 miles per second.
Continue reading Geminid Meteor Shower Mooned Out and Other Celestial Offerings