Ashbourne SKY WATCH week of Wednesday 9 September
We are near to New Moon, which is on Sunday 13 September. So the Milky Way, dim objects and deep sky observations can be done without Moon light to disturb. The sky is dark enough from 9.20 pm onwards and the Milky Way is at its best around 11.30 pm.
The planet Venus is rather close to the Sun, but moves slowly further away. The planet is best seen from 4 am to 6.30 am in the constellation Cancer. Mars is close to the Sun too and best seen from 4 am to 6 am in the constellation Leo. Jupiter is even closer to the Sun and harder to find between 5.35 am and 6.20 am in the constellation Leo. Saturn is best seen from 8 pm to 10 pm in the constellation Libra. You will need a binocular or smaller telescope to find Uranus. This planet is best seen from 10 pm to 5 am.
The Sun rises at 6.29 am and sets at 7.37 pm. In a week's time the Sun rises 12 minutes later and sets 16 minutes earlier.
Wednesday 9 September
Today in 1839 John Herschel made the first photograph on a glass plate. The image he captured was of the 40 foot, 48" aperture telescope used by his father William Herschel in Slough. It is also the 40th Anniversary of the Viking 2 Launch. The Mars Orbiter and Lander were launched in 1975.
The Gegenschein is visible after midnight at 1.10 am. Gegenschein is a faint glowing patch of sky relatively good for observation 32° above the Southern horizon. It will be in the constellation Aquarius.
The Moon's Earthshine is visible at 5.15 am. The 8% Moon is close to Venus, only 4 lunar diameters away.
Today in 1984 the DNA fingerprinting was discovered in Leicester by Alec Jeffreys as X-ray films of his tests first revealed the possibility.
At 10.43 pm a bright flare appears in the North North East at 10° in the constellation Auriga.
The Gegenschein is visible after midnight at 1.10 am. Gegenschein is a faint glowing patch of sky relatively good for observation 32° above the Southern horizon. It will be in the constellation Aquarius.
In the early morning the Moon, Mars, and Venus will appear close together in the sky. At 5.45 am the Lunar crescent is visible, 49 hours before New Moon. The Moon is 22° from the Sun and is only 4% illuminated. The Moon rises at 4.36 am and 117 minutes before the Sun. Watch the Moon's Earthshine at 6 am. The Sun rises at 6.33 am in the East.
Daytime early morning and a challenge for those with telescopes. At 7.03 am the International Space Station (ISS) crosses the disk of Jupiter. Transit duration is only 0.03s, so do record while you will not see. The event is visible in the East at 14° high.
The Gegenschein is visible after midnight at 1.10 am. Gegenschein is a faint glowing patch of sky relatively good for observation 33° above the Southern horizon. It will be in the constellation Aquarius.
A very bright flare appears at 4.57 am in the South West at 57° in the constellation Pisces.
ISS appears at 6.03 am in the South West. ISS will reach its highest point in the sky, culmination we call, at 6.07 am in the South South East at 29° and disappears at 6.12 amin the Eastern horizon.
The Lunar crescent is visible under perfect conditions at 6.15 am, only 25 hours before New Moon. The Moon is only 1% illuminated but only 11° from the Sun. The altitude of the Moon is only 4°. You will need a clear and free horizon to observe. The Moon rises at 5.40 am, 55 minutes before the Sun. A telescope is required to find the crescent Moon and also the planet Jupiter is close, with about 4° Limb separation or 7 lunar diameters. Sun Rise is 6.34 am.
Today in 1962 President John F. Kennedy delivered perhaps the most famous space speech ever given. Speaking at the stadium of Rice University, the text of his speech included these memorable lines, "We choose to go to the Moon. We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win, and the others, too. It is for these reasons that I regard the decision last year to shift our efforts in space from low to high gear as among the most important decisions that will be made during my incumbency in the office of the Presidency."
A very bright flare appears at 9.35 pm in the East North East at 48° high in the constellation Andromeda.
The Gegenschein is visible after midnight at 1.10 am. Gegenschein is a faint glowing patch of sky relatively good for observation 33° above the Southern horizon. It will be in the constellation Aquarius.
ISS appears at 5.11 am in the South South West at 11°. Culmination is at 5.14 am in the South South East at 20° high and disappears at 5.19 am in the Eastern horizon.
A Partial Solar Eclipse occurs this early morning of 13 September. The eclipse is not visible in the UK, but crossing Africa and the Indian Ocean and is at maximum at 7.54 amour local time.
It is New Moon at 7.41 am. This is the farthest New Moon of the year. Former farther New Moon was on 26 July 2014. The next farther New Moon is on 30 October 2016. It is called the “Shallow point” and also known as the minor lunar standstill. It occurs over the next lunation, as the Moon’s orbit reaches a shallow minimum of 18.1 degrees inclination with respect to the celestial equator… the path of the Moon now begins to widen towards 2025.
A few flares appear this evening. A bright flare appears at 9.34 pm in the East at 71° high in the constellation Cygnus. A second flare at 9.47 pm in the North at 12° high in the constellation Lynx. And the last bright flare appears at 10.35 pm in the North East at 14° in the constellation Auriga.
The Gegenschein is visible after midnight at 1.10 am. Gegenschein is a faint glowing patch of sky relatively good for observation 32° above the Southern horizon. It will be in the constellation Aquarius.
At 5 am the Zodiacal Light is good for observation low above the Eastern horizon. Try to look for this triangle of light in the East.
ISS appears at 5.52 am in the South West at 8° high. Culmination of ISS at 5.56 am in the South South East at 42° and ISS disappears at 6.01 am in the Eastern horizon. ISS is close to the bright star Bellatrix at 5.56 am with a separation 0.859° and close to Betelgeuse with a separation of 1.202°. ISS is close to Venus at 5.58 amwith a separation of 0.776°. Worth to watch. Send in your images and footage!
The Moon is in apogee at 12.42 am. This is the farthest apogee of the year. Former farther apogee was at 24 August 2014. The next farther apogee is at 31 October 2016.
A bright flare appears at 9.31 pm in the North at 16° high in the constellation Lynx.
The Gegenschein is visible after midnight at 1.10 am. Gegenschein is a faint glowing patch of sky relatively good for observation 34° above the Southern horizon. It will be in the constellation Aquarius.
At 5 am the Zodiacal Light is good for observation low above the Eastern horizon. Try to look for this triangle of light in the East.
ISS appears at 5.01 am in the South South West at 22°. Culmination at 5.02 am in the South South East at 31° high and disappears at 5.07 am in the Eastern horizon. ISS passes some bright stars. At 5.02 am ISS is close to Alnilam in Orion with separation of 0.406°, at 5.03 am close to Alnitak, also in Orion, with separation of 1.406° and at 5.04 am ISS close to Procyon in Canis Minor with a separation of 0.662°. Worth to watch.
Today in 1830 the Liverpool to Manchester line was ceremonially opened in England. It was built by George Stephenson, a principal inventor of the railroad locomotive. His famous Rocket locomotive, won the Rainhill trials in 1829 as the fastest of the competing locomotives. This line was the world's first intercity passenger railway operated solely by steam locomotives.
The Lunar Crescent is visible at 7.40 pm, 60 hours after New Moon. The Moon is 6% illuminated and sets at 8.11 pm, 48 minutes after the Sun.
A very bright flare appears at 9.25 pm in the North at 18° high in the constellation Lynx.
The Gegenschein is visible after midnight at 1.10 am. Gegenschein is a faint glowing patch of sky relatively good for observation 34° above the Southern horizon. It will be in the constellation Aquarius.
At 5 am the Zodiacal Light is good for observation low above the Eastern horizon. Try to look for this triangle of light in the East.
ISS appears at 5.42 am in the West South West at 13° high. Culmination or highest point in the sky is at 5.45 am in the South South East at 57° and ISS disappears at 5.50 am in the East.
Today in 1662 the first recorded astronomical observation of the first Astronomer Royal was John Flamsteed's observation of a solar eclipse from his home in Derby at the age of 16, about which he corresponded with other astronomers. Flamsteed's interest in astronomy was stirred by the solar eclipse, and besides reading all he could find on the subject he attempted to make his own measuring instruments.
A bright Iridium flare appears at 10.27 pm in the North East at 18° high in the constellation Auriga.
The Gegenschein is visible after midnight at 1.10 am. Gegenschein is a faint glowing patch of sky relatively good for observation 35° above the Southern horizon. It will be in the constellation Aquarius.
A very, really very bright flare appears at 4.36 am in the West South West at 51° altitude in the constellation Andromeda.
The International Space Station (ISS) appears at 4.50 am in the South South West at 38° high. Highest point in the sky or culmination is at 4.51 am in the South South East at 45° and ISS disappears at 4.56 am in the Eastern horizon.
At 5.10 am the Zodiacal Light is good for observation low above the Eastern horizon. Try to look for this triangle of light in the East.
Get in touch with me viawww.patrickpoitevin.weebly.com if you need more information.
Ashbourne SKY WATCH Special week 9 September - The sky is dusty!
Gegenschein
In this week’s SKY WATCH, I mentioned you could observe the Gegenschein on some mornings. Gegenschein is a faint brightening of the night sky in the region of the anti-solar point. It is a patch of very faint nebulous light. It is sometimes seen in the morning sky night. It is very hard to see. Go away to rural areas where you do not have any artificial lights. Try to look at nights with no Moon. The Gegenschein is visible only with the unaided eye, as it is far too large and diffuse to be viewed with a telescope or even binoculars.
The word Gegenschein is German and means countershine or counterglow since it is always opposite or "counter" in position to the Sun in the sky. None of the current explanations does satisfactory explain the exact phenomenon. It is believed it is the image of the Sun reflected from gas and dust outside the atmosphere. The effect is caused by matter spread around that reflects the light from the Sun, and is related to the zodiacal light. So the exact nature of the Gegenschein is still somewhat of a mystery, though most think that like the Zodiacal Light it might be some sort of tail formed by minute particles from our atmosphere that are streaming out into space away from the Earth in the opposite direction from the Sun.
Zodiacal light
The Zodiacal Light and Gegenschein are caused by Sunlight reflecting off tiny interplanetary dust particles (IDPs). The particles, like the planets, lie in the plane of the Solar System. These sky glows are one and the same phenomenon. They only look different in shape and brightness because of the angle of the light reflected from the particles in the interplanetary dust cloud.
Your best chance to catch a glimpse of these phenomena is in spring and autumn when the Ecliptic makes a steep angle to the horizon. Look towards the West after Sunset and after twilight has completely subsided, or towards the East before dawn. The closer you live to the Tropics, the better your chances of seeing the glows. During the next few weeks on a clear Moonless early morning, and you are far from any haze and bright lights, keep a close watch on the Eastern horizon about two hours before Sunrise. If you are lucky you might catch a glimpse of a ghostly column of light extending upward into the sky.
For northerners at this particular time of the year, it is just before morning twilight begins (about 90 minutes before Sunrise), that the Zodiacal Light should appear at its brightest and most conspicuous. For those who live in the Southern Hemisphere, the best views now are in the Western evening sky right after Sunset. Those who live in the tropics or at the equator are luckiest of all since the Zodiacal Light is always very conspicuous from these regions. This is because from these locations the ecliptic is always favorably oriented allowing views of the Zodiacal Light both in the Western evening sky and Eastern morning sky all year long.
Most of the IDPs are between 10 and 300 micrometers across or 4/10000 to 1/100 of an inch and are composed mainly of silicates, similar to much of the material found in the Earth’s crust. They are largely confined to the inner Solar System, stretching out to the orbit of Jupiter at 5.2 AU or 779 million kilometers from the Sun.
Many have been fooled into thinking that it is the beginning of morning twilight and indeed the Persian astronomer, mathematician and poet Omar Khayyam referred to this ghostly glow as the "false dawn" in his poem The Rubaiyat.
That faint ghostly glow was once thought to be solely an atmospheric phenomenon. Perhaps reflected Sunlight shining on the highest layers of Earth's atmosphere. We know now that while it is indeed reflected Sunlight, it is being reflected not off our atmosphere, but rather off of a non-uniform distribution of interplanetary material; debris left over from the formation of our solar system.
Lunar standstill or shallow point
In September we have a lunar standstill or shallow point. No, the Moon’s orbit does not stop! No reason to panic … The Shallow point occurs over the next lunation, as the Moon’s orbit reaches a shallow minimum of 18.1 degrees inclination with respect to the celestial equator… the path of the Moon now begins to widen towards 2025.
The term "lunar standstill" was first used by archeologist Alexander Thom in his 1971 book "Megalithic Lunar Observatories". The term "solstice", which derives from the Latin solstitium: sol- (sun) + -stitium (a stoppage), describes the similar extremes in the Sun's varying declination. Neither the Sun nor the Moon stands still obviously. What stops is the change in declination.
At a major lunar standstill, which takes place every 18.6 years, the range of the declination of the Moon reaches a maximum. As a result, at high latitudes, the Moon's greatest altitude or at culmination, when the Moon crosses the meridian, changes in just two weeks from high in the sky to low over the horizon. This time appears to have had special significance for the Bronze Age societies who built the megalithic monuments in Britain and Ireland, and it also has significance for some neo-pagan religions.
The altitude of the Moon at culmination is with a minor lunar standstill at 53.5° at its greatest and 16.5° at its least. For a major lunar standstill the Moons altitude at culmination is at its greatest 63.5° and 6.5° at its least. We had a major lunar standstill in June 2006 and the next one will be in April 2025. A minor lunar standstill was last in February 1997 and we have our next in October 2015, and thereafter March 2034.
Not all the maxima are observable from all places in the world. The Moon may be below the horizon at a particular observing site during the maximum, and by the time it rises it may have a lower declination than an observable maximum at some other date.
For us we have the highest visible maximum during civil twilight on 15 September at 6.30 am at an altitude of 64 degrees. The Moon is 42% waning. The highest visible maximum during darkness is on 7 March at 8.43 pm at an altitude of 64 degrees. The Moon is 60% waxing. The lowest visible minimum during civil twilight is on 29 September at 6.44 pm at 9 degrees altitude. The Moon is 43% waxing. The lowest visible minimum during darkness is on 2 September at 9.50 pm at an altitude of 7 degrees. The Moon is 70% waxing.