Download Observing Information for Waddesdon, 4th October 2014

Observing Information for Waddesdon, 4th October 2014
The Moon on the evening of the 4th October 2014
Plato
A crater and the Lunar Alps with the floor flooded with lava, Diameter 101 km.
Sinus Iridium
The Bay of Rainbows, a 400 km crater in the side of the Mare Imbrium. The Montes Jura form the
Northern walls
Mare Imbrium
One of the largest lunar seas, formed by a colossal impact that generated a 1250 km diameter crater
that’s been flooded by lava and extensively modified by later impacts.
Copernicus
A relatively young crater only about one billion years old. Diameter 93 Km.
Mare Serenitatis
650Km diameter lunar sea, also thought to be formed as a large impact that was flooded with lava.
Mare Crisium
Sea of Crises. This sea is about 620 by 570 Km in size. It is pretty obvious, even with the unaided
eye.
Mare Tranquillitatis
This sea is about 700Km in diameter and as with all the lunar seas is thought to have formed as a
result of a large impact basin being flooded with lava between 4.5 and 3.6 billion years ago. Apollo
11 landed near the southern boundary of this area.
Tycho
The youngest major crater, maybe only 100 million years old. Has an extensive ray system covering
much of the visible side of the Moon. 86Km in diameter.
Clavius
An impressive crater in the Southern highlands. 225Km in diameter. Has a string of craters across
it that form a curved line with the craters in order of size.
Other Objects
The Summer Triangle
This is an asterism of three bright stars, Deneb, Vega and Altair. It is easily visible with the unaided
eye and is useful for locating other objects at this time of year.
Deneb is the bright star that’s very high to the SE. It’s the brightest star in the constellation
Cygnus. It is 1400 light years distant so is a tremendously bright star
Vega is the brightest of the three stars; it is almost overhead high to the S or SW and is the brightest
star in the constellation Lyra. It is 25 light years away so quite close.
Altair is south and about half way from the horizon to the Zenith. It is the brightest star in the
constellation Aquila, the Eagle. It is the closest at only 16.7 light years away.
Albeiro
This is a less bright, third magnitude, star about half way between Vega and Lyra. It looks like a
normal star to the unaided eye but with a telescope it shows as a very pretty double star with one
component appearing blue and the other yellow. This is one of the nicest sights in the sky.
The Double Double
Just over a degree above and left of Vega is a fourth magnitude star – Epsilon Lyra. In binoculars it
shows as a double star with two almost equally bright stars. In a telescope with a reasonable
magnification both of these stars shows up as a close double star so we get the double double. The
doubles are quite close and it can take a while to get your eye in to be able to split them.
The Ring Nebula
Just under Vega is a parallelogram of faint stars and about half way between the lower two is a faint
ring or oval. It needs a moderate sized scope and moonlight or haze may wash it out. This is a
cloud of gas that has recently been ejected from a star as it finishes its life. The remnant of the star
is a faint white dwarf that emits most of its light in the ultra violet and this is causing the nebula to
glow. The nebula contains heavier elements, in particular Oxygen, and the light this emits is most
of what we see. A narrow band OIII filter can help us see this even with moonlight.
The Coat Hanger asterism
This is a group of stars that look a bit like a coat hanger. It’s located about 1/3rd of the distance from
Altair to Vega. It’s a good binocular object.
M11, the Wild Duck cluster
This is a very rich open cluster of stars in a wedge shape. The cluster is about 220 million years old
and it’s about 6,000 light years away.
The Andromeda Galaxy
This is to the ESE and about half way up. Finding the square of Pegasus, then Andromeda is the
best way to this. It is very large but all we can usually see is the central core, especially with the
Moon washing it out. This is the nearest major galaxy, about 2 million light years away.
M15
A globular cluster in Pegaus. It is well up to the SE.
M13
The Globular cluster in Hercules. This is high to the W and should be visible over the house.
Gamma Delphinus
A fourth magnitude double star forming the nose of the dolphin.
M27 the Hourglass
This may be washed out by the Moon but a UHC or OIII filter may help.
The Double Cluster
May be OK over the trees to the NE
The Milky Way
Runs from the SW, through Cygnus, and almost overhead. May be washed out but may be visible
overhead through Cygnus.
Planets:
There are no major planets on view. Saturn has just set in the W; Mars is very low to the SW and
will be hidden by trees or the house. Pluto is slightly higher but still low to the SSW and too dim to
see. Uranus is low to the E and Neptune is SE. This is the most likely to be seen but will be a
small bluish disk. Jupiter is a morning object, not rising until about 2 am. Venus and Mercury are
both close to the Sun.
General Questions
What are these M numbers?
These objects were first catalogued by Charles Messier and his collaborators in France in 1771. He was searching for
comets and made a list of objects that looked like comets but were not. There are a total of 110 Messier objects.
Chris Rowland, September 2014
This shows the sky at 20:00 on the 4th October 2014, looking away from the house.