Babe Among the Stars - November 2007
Created | Updated Jun 4, 2008
Mortal as I am, I know that I am born for a day. But when I follow at my pleasure the serried multitude of the stars in their circular course, my feet no longer touch the earth - Ptolemy
Comet 17P/Holmes
Perseus does not look 'Perseus' familiar to us due to
the bright stellar object now.
- Comet 17P/Holmes observer reporting from Japan.
If there's anything guaranteed to get astronomers excited, it's something
unusual happening, right now! Amateur
astronomers are nocturnal hobbyists, a kind of secret society
which only gives itself away when the run-of-the-mill becomes the
extraordinary. Take Comet 17P/Holmes for example. An insignificant
visitor to the inner Solar System first
discovered on 6 November, 1892, it takes just under seven years to
orbit the Sun once. Barely worth a mention
in newsprint, Comet 17P/Holmes suddenly became a media megastar in
October 2007.
Instead of being around 17th magnitude - only visible to powerful
telescopes - it had an eruption, brightening the comet by a factor of
a million, and became 3rd magnitude. The eruption could have been
caused by a build-up of gas below the surface suddenly spewing out, or
another space body could have impacted with it. Comet 17P/Holmes was
passing through a particularly volatile place at the time, the Asteroid Belt, between the orbits of Mars and Jupiter,
where there are lots of potential collisions. The eruption on the
comet made it
easy to spot with the unaided eye, even in cities with heavy light
pollution.
Ancient cultures (the Chinese, in particular, thought comets were
'celestial ambassadors') would have had a field day with this comet's
eruption, probably astrologers are already
writing up forecasts of momentous events
with the odd few lapping it up.
How to See the Comet
Look outside after the sky is dark, to the Northeast. The comet is
currently in the constellation named after the hero Perseus, which is below the more familiar 'W' of
Cassiopeia. If you're familiar with the
constellations at all, you'll now see a new, bright yellow 'star'. A
telescope or binoculars reveals the fuzzy corona surrounding
the comet. It's not known how long the comet will be viewable so take
advantage of this unexpected bonus while you can!
Comet
17P/Holmes was featured as Astronomy Picture of the Day's
star-of-the-day for 3 November, 2007. The celestial firework was
honoured again on 5 November when it displayed a green coma and blue tail. On 9 November Astronomy Picture of
the Day published an image of the comet and the surrounding skyscape, and the
following day a stunning close-up, comparing the comet to
a cosmic jellyfish.
- Chat about your celestial observances at the H2G2 Astronomy Society.
November
November is 30 days long and comes from the Latin word novem
meaning nine.
Venus is a glorious pre-dawn sight -
definitely worth beating the alarm clock for.
Still visible, even at this time of year, are the bright stars
which make up the Summer Triangle, Deneb,
in Cygnus, the Swan, Vega in Lyra, the
Harp, and lower down is Altair, in Aquila, the Eagle.
Jupiter is visible in the evening until
early December - you'll need to locate the constallation Sagittarius.
Do train your binoculars as all four of Jupiter's main moons are on
show.
Comet
17P/Holmes is still visible even though it's heading away from
us now. This comet has brightened over a million-fold this time
through the inner solar system, providing astronomers with spectacular views and a 'new look' Perseus.
17: The Leonids meteor shower peaks
in the early hours of Sunday 18 Nov. A few tips if you're travelling
to a dark-sky viewing area: Make sure you have permission to use the
land if it's privately owned. Take a flask of hot drink with you.
Dress warmly (scarf, hat, gloves, coat, thick socks, boots) as the
mid-November nights are cold in the Northern hemisphere. Sit in a
reclining chair, or you'll end up with a cricked neck. A folding deck
chair is a good investment for hands-on astronomers. If you have to
lie on the ground, spread a thick blanket, sleeping bag or old quilt
over it first. Then lie down and look up! Meteors can appear in any
part of the sky, although their trails will tend to point back toward
the radiant.
24: Don't miss the 24 November Full
Moon which occurs as it travels closest to the Earth. It's one
of the largest of the full Moons of
2007.
30: Before dawn it's worth looking out for the waning gibbous
Moon, the ringed planet Saturn, and
Regulus (alpha Leonis aka Cor Leonis [Lion's Heart]), which are
all nicely lined up. Regulus is a first magnitude star so not hard to
miss.
The Ever-changing Moon
We are so lucky to have our Moon. It's so gorgeous it never fails
to take my breath away whenever I gaze upon its stunning face. It's
different every time, yet it's the same moon. Sometimes it's big and
full, others it's doing a great impersonation of a Cheshire cat.
It's a standing joke in my family when there's a full moon, to say
'full moon, half-moon, total eclipse' then pretend you're eating a
jaffa cake. No doubt that joke will be lost on anyone who can't
remember the advert or doesn't receive commercial TV. No worries, I'd
love you to share your family ditties with the rest of us, do you make
wishes on a new moon? Do you turn your silver over when there's a full
moon? Do you wish on a shooting star? Post below and tell h2g2!
Phases of the Moon
Here are the phases of the Moon for the month:
- New Moon: 9 Nov
- First quarter: 17 Nov
- Full Moon: 24 Nov
- Last quarter: 1 Dec
