The Sky this Month - February 2017

Hunting The Hare

Nestled below Orion is a lazy cross of stars. This is Lepus the Hare. A some what small constellation that measures only 290 square degrees of sky, making it 51st in over all size. The Hare seems to be chased by Orion’s two hunting dogs, named Sirius and Procyon. Lepus does have the distinction of being the first constellation catalogued by Ptolemy in the second century BC. The bright star at the centre of the asterism is named Arneb, from the Arabic meaning “the Hare”. The alpha star is about 1,300 light years away and shines at magnitude 2.5. It is a spectral class F0 supergiant that is 13,000 times brighter than the Sun and 75 times its diameter. If placed in our solar system Arneb would reach the orbit of Mercury.

A few choice objects inhabit Lepus such as the large galaxy NGC 1744. Measuring 7.5 by 3.5 arc minutes, this barred spiral galaxy is located 34 million light years away. Although it has a magnitude value of 11.1, its face-on orientation makes this galaxy a bit difficult to spot. It can be found at the bottom right side of the constellation and about four degrees south of Epsilon Leporis.

Moving east we come across the only Messier object associated with Lepus. M79 is a highly resolved globular cluster that lies 42,000 light years from us and 118 light years wide. By galactic standards, this object is far from home as most globular clusters tend to reside close to the centre of the Milky Way and not 60,000 light years away. M79 measures 9.3 arc minutes wide or about a third the size of the full moon. At magnitude 7.7, it is an easy binocular object.

Located at the top of Lepus is IC418. Dubbed the Spirograph Nebula because of its similar design from the mid 1960’s drawing toy, its intricate structure is still a puzzle to scientists. This planetary nebula is located some 2,000 light years away and measures about a third of a light year across.

For a two week period commencing Feb 13, head out to dark skies to view and photograph the zodiacal lights in the west. This glow is left over interplanetary dust from the early creation of the solar system. Best times to see this band is close to the spring and fall equinox. The zodiacal lights are angled along the ecliptic (zodiac) from the horizon to a bit south of the Pleiades. If weather is not in your favour, you will also have a two week window in March.

The two western planets are now separating with Venus is starting pull away from Mars and sinking down to the west. At the beginning of the month Venus is only 39% lit as seen through a telescope and by month’s end, its large but thin crescent will be a mere 15% lit. It will be at its brightest on the 17th at magnitude -4.34.

Jupiter now rises around midnight local time with the star Spica a few degrees south of the planet. By comparison, Jupiter is 42 light minutes away while the star is 250 light years from us. Saturn has now crossed into the morning sky and is seen rising from the south east by 5 a.m. local time to the left of Scorpius.

There will be a penumbral lunar eclipse on February 10 from 22:32 UT to 2:55 UT on the morning of the 11th. The full Snow Moon will slide into the outer portion of the Earth’s shadow. Unlike the dramatic colour change of a total lunar eclipse when the Moon turns orange, the penumbral event is hardly noticeable. Two weeks later on the 26, there will be an annular solar eclipse seen from the lower portion of South America, the Atlantic Ocean and the western part of Africa.

Until next month, clear skies everyone.

Gary Boyle

Twitter: @astroeducator

Author: Gary BoyleeNews date: Wednesday, February 1, 2017Category: Northern SkiesFile:  Lepus.pngTweet::  Pages

The Sky This Month - January 2017

The Winter Milky Way

Over the course of the year, we have the opportunity to enjoy our Milky Way Galaxy in varying degrees of elevation and richness. Lazy days of summer reward us with splendid views of the central portion of the galaxy to the south in Sagittarius and Scorpius. Fast forward to the present and we can still enjoy Cygnus the Swan sinking in the western sky. In fact the “summer triangle” comprised of Altair, Vega and Deneb are still visible at 7 p.m. local time. From a dark location, follow the glow of millions of distant stars through Cepheus, Cassiopeia, Perseus, Auriga and down the left side of Orion through Monoceros. By the time you get down to this point, the band thins out but never the less, is still visible.

Along the way, many binocular targets as well as photographic challenges await. Take for instance is the Double Cluster in Perseus. Catalogued as NGC 869 and NGC 884, they are roughly 7,000 light years away and glimpsed with the unaided eye. Binoculars and a telescope with a wide angle eyepiece show the brilliance of these side by side open star clusters that appear like diamonds on black velvet. To the astrophotographers, these twin objects are a piece of cake. However a few degrees away are two large emission nebulas known as the Heart and Soul Nebulas catalogued as IC 1805 and IC 1848 respectively and are some 6,500 light years away. A group photo is stunning.

Moving along the starry band, we stop at the constellation Auriga where we find a great trio of open clusters. They are M36, M37 and M38. Binoculars are required to find all three. Continuing we find ourselves face to face with Orion the Hunter. This iconic constellation is Orion Nebula is 1,500 light years away and a birth place of star creation where shells of gas and dust as slowly condensing and collapsing to one day form suns. The Orion Nebula aka M42 is an extremely easy target to spot even seen from suburbs. Just look for the sword that hangs down from the three stars forming the belt.

A bit of a challenge might be the Flame Nebula. NGC 2024 is another stellar nursery and is located very close to the left most star of the belt called Alnitak located 817 light years away. The Flame is much farther back in space. Moving a little south from the Flame is the very illusive Horsehead Nebula. I had the chance to IC 434 (with great difficulty) through a 25 inch telescope. Needless to say, this is a photographic object. The Horsehead is located the same distance as M42 and is also part of the Orion Molecular Cloud Complex.

Rounding out the tour is the Rosette Nebula located in Monoceros. Here is another emission nebula producing hundreds of stars. Estimated distance of 5,000 light years away, the Rosette is huge. With binoculars you can spot the young open cluster at the centre made up of three pairs of stars. From here you will need a wide angle telescope to try to see the fainter portions of the Rosette. The entire complex measures close to four full moons by three moons in the sky. The red colour is only revealed by photographic means.

Venus is moving higher in the western sky and inching towards Mars. In dark sky conditions Venus can cast a shadow on a sheet of white paper. As the planet moves closer to its greatest elongation from the Sun (47 degrees) on the 12th, it sports a beautiful half lit phase much like the moon. Mars is getting fainter compared to the great show we had at the end of May. On Jan 1, Mars will be more than 250 million kilometres from Earth verses its 75 million kilometre close approach a few months ago. The planet Jupiter is a bit dimmer than Venus but never the less a brilliant object rising in the east around 1:30 a.m. local time.

The Quadrantids meteor shower will peak on the morning of 4th. This is a very short lived shower that lasts a few days, so its peak of seeing 50 to 100 meteors per hour does not last very long. The radiant can be found half way between the end star of the Big Dipper and the constellation Bootes. The full Wolf Moon occurs on January 12 at 6:34 a.m. eastern. New moon occurs on the 27th.

Until next month, clear skies everyone.

Gary Boyle

Twitter: @astroeducator

Author: Gary BoyleeNews date: Sunday, January 1, 2017Category: Northern SkiesFile:  2017 - 01 chart 1.png 2017 - 01 chart 2.png 2017 - 01 chart 3.png 2017 - 01 chart 4.pngTweet::  Pages

The Sky This Month - December 2016

Long Winter Nights

Winter’s brighter stars are coming into sight earlier each evening. By 8 p.m. local time at the beginning of this month, Orion is nicely perched in the eastern horizon. Moving vertically we see his combatant – Taurus the Bull with bright star Aldebaran (its eye). Still higher in the sky is a small but easily recognized cluster of stars called the Pleiades or The Seven Sisters. Amongst the 200 of so stars that make up the 450 light year distant cluster, seven are seen with the unaided eye and a great test for how good are sky conditions. These three make a great photo opportunity.

To the right of Orion is a long chain of stars that eventually disappears past the southern horizon. In fact the constellation end at -57 degrees south with the right star named Achernar that rivals Procyon in brightness at magnitude 0.5. Eridanus is listed as the 6th largest area in the sky and is home to many celestial objects.

We will start off with a large, faint reflection nebula called the Witch Head Nebula catalogued as IC 2118. It is located two and a half degrees west of Rigel – the bottom right of the famous hunter, Orion. Rigel is a blue supergiant star located 770 light years (ly) from earth with its light equivalent to 40,000 times that of our Sun. This is the celestial lighthouse that is illuminating the IC 2118. But this 1000 ly distant patch of faint gas and dust can only be seen visually under very dark conditions along with a large scope. With its great dimensions of six lunar diameters long by two diameters wide, it does make a great wide angle photographic challenge.

Next is the planetary nebula named Cleopatra’s Eye or NGC 1535. Appearing somewhat like the Eskimo nebula, this planetary nebula appears as a magnitude 9.5 patch of light, aqua in colour with a central dot what stands out. It is a must see on your observing list. Moving ten degrees to the west of Rigel and six degrees north, you well come across a nice trio of elongated galaxies. NGC 1625, 1622 and 1618 can be found by first locating magnitude 4.1 Nu Eridani.  At magnitudes 12.4, 12.3 and 12.6 respectively, they are about 11 arc seconds north the east of this bright star.

The multiple star system named Keid is quite interesting as it is a classic example of a white dwarf. At a distance of only 16 light years away, Keid also known as Keid A, has two dwarf stars close by namely the B and C components, are white and red in colour and are quite close together. Power is essential. This star system is also known as Omicron 2 or 40 Eridani.

As for the planets, Saturn is lost in the solar glare after sunset and will be in conjunction with the Sun on the 10th. Venus on the other hand is higher in the western sky and at magnitude -3.6, is extremely easy to find. It continues to pull away from the Sun until its greatest elongation on January 12. Mars is still visible at magnitude 0.8 during the early evening but is getting progressively fainter and be at magnitude 1.0 at the end of the month. Jupiter rises just after 3 a.m. local time on Dec 1. Be sure to follow the shadows and transits of the Jovian moons located on page 236 of the RASC Observer’s Handbook 2016.

The winter solstice officially occurs on December 21 at 10:44 UT. The full Cold or Long night moon occurs on December 13 at 19:06 p.m. eastern which is just in time to block out some of the Geminid meteor shower which peaks the same night. The parent to this shower is asteroid 3200 Phaethon and delivered about 120 meteors per hour under good conditions. Eight night later will be the peak of the Ursid meteor shower which only produces about 10 meteors per hour. New moon occurs on Dec ember 29 at 6:53 UT.

Until next month, clear skies everyone.

Gary Boyle

Twitter: @astroeducator

Author: Gary BoyleeNews date: Thursday, December 1, 2016Category: Northern SkiesFile:  2016 - 12 chart 1.png 2016 - 12 chart 2.pngTweet::  Pages