Saturday: The bright star Antares is about a fist held upright
and at arm’s length above the south-southeast horizon at 11 p.m.
Sunday: The month of June is named after Juno, the queen of
the Roman gods and the mythological protector of the Roman state. In ancient
Rome, the month began when the crescent moon was first seen in the evening sky
from Capitoline Hill in Rome. If we still started months this way, June would
have started a couple of days ago, right after the moon was last new. Celebrate
the first sunset in June by actually watching it… and then keeping your gaze
fixed on the west-northwest horizon until it is dark enough to see Mercury,
Jupiter, and the moon in a line pointing away from the Sun. At 9:30 p.m.,
Mercury is about a half a fist above the west-northwest horizon, Jupiter is two
fists above the west horizon, and the moon is… well, if you have found Jupiter,
the can find the moon.
Monday: In 1979, the group Foreigner recorded the song “Head
Games”. They could have been singing about the constellations Hercules and
Ophiuchus when they said “head games, it’s just you and me baby, head games, I
can’t take it anymore” because the heads of these two constellations have been
right next to each other in the nighttime sky for all of human history. And
just to make it easy for you, a star that bears an Arabic name that means “the
head” represents each head. In Hercules, it's Ras Algethi (head of the
kneeler); in Ophiuchus, Ras Alhague (head of the serpent charmer). At 11 p.m.,
Ras Alhague, the brighter of the two, is a little more than four fists held
upright and at arm’s length above the southeast horizon. Ras Algethi is about a
half a fist to the upper right of Ras Alhague.
Tuesday: Nearly 400 years ago, Galileo viewed the Pleiades
star cluster through his telescope and saw that the seven or so stars in the
region visible to the naked eye became many more. There are two main types of
star clusters. Open star clusters are groups of a few dozen to a few thousand
stars that formed from the same cloud of gas and dust within our galaxy. Stars
in open star clusters are young as far as stars go. Globular clusters are
groups of up to a few million stars that orbit the core of spiral galaxies such
as our own Milky Way. One of the most well known star clusters is the globular
cluster in Hercules, an object that is fairly easy to find with binoculars.
First find Vega, the bright bluish star five fists above the east horizon at 11
p.m. Two fists above Vega is a keystone shape. Aim your binoculars at the upper
left hand star of the keystone. The globular cluster is one third of the way to
the rightmost star of the keystone. It looks like a fuzzy patch on the obtuse
angle of a small obtuse triangle. If you don’t know what an obtuse angle is,
you should not have told your teacher, “I’ll never need to know this stuff”.
Wednesday: Mars is three fists above the southeast horizon
at 11 p.m.
Thursday: You can set your watch tonight by carefully
observing Segin, the left-most star in the W-shaped Cassiopeia. It will be due
north at exactly 10 p.m. However, another star in Cassiopeia is causing
astronomers to doubt whether or not they can use neutron stars as the most
precise known clocks in the universe. Neutron stars have such a precise spin
rate that they are used to set clocks on Earth. But the neutron star called 1E
2259+586 (how’s that for a celebrity baby name) exhibited a spin glitch that
astronomers had never seen before. To find out more about this new excuse for
being late, go to http://goo.gl/C4V8R1.
Friday: Saturn is three fists above due south at 11 p.m.
The positional information in this column about stars and
planets is typically accurate for the entire week. For up to date information
about the night sky, go to https://nightsky.jpl.nasa.gov/planner.cfm.
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