The Night Sky This Month: November 2017

Image Credit: timeanddate.com

In November, the “Summer Triangle” can be seen rising in the early evening sky before making its way westwards, with the Milky Way passing through two of the stars in this huge asterism. These are Vega in Lyra and Altair in Aquila, while Deneb in Cygnus makes up the third star in this prominent celestial marker.

To the east of Cygnus can also be found the great square of Pegasus, which adjoins the constellation of Andromeda, famous for containing the deep-sky object M31, which at 2.5 million light-years distant is the Earth’s nearest major galaxy. Meanwhile, to the north of Cygnus lies the constellations of Cassiopeia and Perseus. In the late evening, the constellation of Taurus then appears in the east, giving stargazers the opportunity to observe the two beautiful star clusters known as the Hyades and Pleiades.

Moon

This month, all lunar observers who are so inclined can join the debate about whether the full Moon that occurs on the 4th of the month is a super moon, or not. At issue are the implications of two major definitions of what constitutes a super moon; according to one definition this full moon is a proper super moon, while according to another definition, this full moon does not even come close to being a super moon. Who is right? Who is wrong? If you want to decide the issue for yourself, more information is available here.

Phases

Full Moon: 4th
3rd Quarter: 10th
New Moon: 18th
1st Quarter: 26th

Planets

Mercury is now an early evening object, setting about an hour or so after sunset by month’s end. However, this apparition is not particularly favourable, and binoculars are required to spot the little planet. If seeing conditions allow, look for Mercury low on the southwestern horizon during twilight.

Venus starts the month rising about 90 minutes before dawn, which reduces to about 60 minutes by month’s end. Although Venus’ brightness remains fairly constant throughout the month, it remains low on the southeastern horizon, where on the morning of the 13th it will form a close pairing with Jupiter, another bright morning object. The two planets will be roughly half the width of the full Moon apart (17 arc minutes), with Jupiter lying to the lower right of Venus, which will be the brighter of the two planets. On the morning of the 17th, Venus, Jupiter, and a hairline-thin waning crescent moon will form a close grouping, with both planets to the right of the Moon. Look for this triangular grouping in the southeast at about 07:00 AM (GMT).

Mars is also an early morning object, rising at about 04:00 (GMT) during all of November and most of December as well. Now moving eastwards through the constellation Virgo, Mars reaches the constellations brightest star, Spica (alpha Virginis) by month’s end. The red planet brightens somewhat during the month, and by the 30th, it will shine at magnitude +1.69, marginally fainter than Spica, which will be shining at magnitude +1.0. This is a great opportunity to compare the ruddy red color of Mars to the steel-blue hue of Spica. On the morning of the 15th, Mars and the waning crescent Moon will form a relatively close grouping about 20 degrees above the south-eastern horizon, with Jupiter rising toward the lower left of the pairing.

Jupiter is now emerging from behind the Sun, and by month’s end, the King of the planets will rise at about 05:30 (GMT) above the east-south-eastern horizon as it begins its long apparition.

Saturn remains low on the horizon for the rest of the year, as it has been for most of 2017. As November starts, Saturn sets around 07:00 PM (GMT), and progressively earlier as the month wears on, to set at about 05:00 PM (GMT) during the last days of the month. However, if seeing conditions allow, Saturn will form a close grouping about 4 degrees above, and parallel with southwestern horizon on the 20th. Note, though, that an atmospheric dispersion corrector may be required to see the grouping this close to the horizon.

Uranus is visible almost throughout the night in the constellation Pisces, shining at magnitude +5.72 about 2 degrees to the rightward of the magnitude +4.26 star Trocularis Septentri (omicron Piscium).

Neptune is now visible during the mid-evening hours in the constellation Aquarius, less than one degree to the lower rightward of the magnitude +3.74 star lambda Aquarii. Note that while the planet’s blue-grey disc can be resolved in small to medium telescopes, a medium to high magnification is required.

Meteor Showers

November sees two meteor showers:

– The Taurids meteor shower is associated with the comet Encke, and produces bright, but slow-moving meteors. It has two peaks, the first of which is expected to occur overnight on the 5th /6th, while the second peak is expected overnight on the 12th /13th. The second peak is expected to be the more productive of the two.

– The Leonids meteor shower is expected to peak on the 19th, but will be best seen almost throughout the night of the 17th /18th, when about 20 or so meteors per hour is expected. Note that moon light will not intrude this year. The Leonids derive from the debris trail of the comet Temple-Tuttle, which orbits the Sun once every 33 years. The next major Leonid meteor storm is therefore only expected toward the late 2020’s.

Deep-Sky Objects

The constellations Perseus and Eridanus are prominent in the northern hemisphere at this time of year, with Perseus almost directly overhead. Below are some details of a few deep sky objects that can now be observed with even modest amateur equipment in these constellations:

Witch Head Nebula (IC 2118)

Witch Head Nebula
Image: NASA/STScI Digitized Sky Survey/Noel Carboni

This faint reflection nebula is around 50 light years long, and located about 1,000 light years away in the constellation Eridanus. Believed to be either a gas cloud, or possibly an ancient supernova remnant, the nebula reflects the light of the star Rigel (located to the upper right of the nebula, but not shown here), in the neighbouring constellation Orion.

The blue color of IC 2118 results from the dust in the nebula reflecting blue light more efficiently than red light, and not from the blue light being emitted by the star Rigel. The Witch Head Nebula has an apparent visual magnitude of 13, with its startling apperance believed to be the result of stellar wind from nearby stars shaping this molecular cloud

The Double Cluster (Caldwell 14, NGC 869 & NGC 884)

The Double ClusterThe open clusters NGC 884 and NGC 869 are collectively known as the Double Cluster, and are located 7,600 and 6,800 light years from Earth, respectively, in the constellation Perseus, near to its border with Cassiopeia. With a combined apparent visual magnitude of 4.3, the cluster pair is visible without optical aid, although a telescope is required to split them apart. A 200mm (8-inch) telescope will then reveal hundreds of blue and white stars scattered throughout the field of view. Both clusters contain in excess of 300 hot, super giant stars, and are approaching us at speeds of 21 km/sec, and 22 km/sec, respectively.

Messier 34 (M34, NGC 1039)

Messier 34
Image: Wikisky

Also located in Perseus, Messier 34 is an open cluster that is located about 1,500 light years away, making it the 6th closest Messier object to Earth, with nearer Messier objects including the Pleiades (M45), the Beehive Cluster (M44), the Ptolemy Cluster (M7), the open cluster Messier 39, the Dumbbell Nebula (M27), and the Orion Nebula (M42). Messier 34
contains about 400 stars that stretch across a distance of about 14 light years, with the whole cluster having an estimated age of less than 250 million years.

In good seeing conditions, M34 can be seen as a faint, blurry patch of light just to the north of an imaginary line drawn between the double star Algol in Perseus, and the star Gamma Andromedae in the constellation of Andromeda.

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