April 2018

Four section members, one new to Deep Sky Section, sent in a total of twenty – one digital images this month.

David Davies concentrated his attention on four open clusters, all of which are Messier objects.

M46 is located in the constellation of Puppis.  Planetary nebula NGC 2438 (above and left of centre) appears to be within the cluster – however it does not share the cluster’s radial velocity, so is likely to be unrelated to it.  The 500 or so stars in M46 are around 300 million years old.

M46, NGC 2438

The other three open clusters are M50 in Monoceros, M67 in Cancer and M44, also in Cancer.

M50
M67

In contrast to M46, the stars in M67 are quite old, around 4 billion years:  within M67 are about 100 stars similar to the sun and many red giants.

M44

Known as the Beehive Cluster (aka Praesepe – Latin for “the manger”) M44 is much closer to the Earth than the other three open clusters.  It is similar in age, distance and proper motion with the Hyades open cluster in Taurus, suggesting that they may have a common origin.

David used an 8″ Richey Chretien telescope at f5.3 and a QSI 583 mono camera plus red, green and blue filters from his observatory in Cambridge.

 

Richard Lewis of Suckley in Herefordshire made his debut to the section with a selection of deep sky objects captured via a Skywatcher ED 80 refractor and a Nikon D7000 DSLR.

M31 the Andromeda Galaxy was thought until recently to be twice or even three times the size of our own.  Latest research indicates that M31 and the milky way are similar in size.

M31

The next two images are of  and M42, the Orion nebula and emission nebula IC 434 (featuring B 33 the Horsehead dark nebula) also in Orion.

M42
IC 434, B 33

The Flame emission nebula is in this image also, at bottom left, energised by zeta Orionis (Alnitak), the bright star above it.

Richards next two images are NGC 7000, the North America nebula emission nebula in Cygnus;  and M45, the Pleiades open cluster in Taurus.

NGC 7000
M45

The young (100 million year old) hot, blue stars in M45 are currently passing through a dust cloud, hence the reflection nebulosity.  The brightest stars in this cluster are visible to the naked eye and have been known to many cultures around the world since ancient times.

 

Mark Beveridge imaged seven deep sky objects from Thainstone, using a 200mm Celestron Edge HD f10.4 SCT and a SXR – H814 mono camera plus red, green and blue filters.

Five are of galaxies, the first three of those in the constellation of Ursa Major:  NGC 3079, NGC 3963, NGC 5322.

NGC 3079
NGC 3963
NGC 5322

The remaining two galaxies are M51 (the Whirlpool) in Canes Venatici and NGC 6015 in Draco.

M51

M51 is a pair of interacting galaxies;  the larger one is M51A or NGC 5194, the smaller galaxy is M51B or NGC 5195.  M51A has an active nucleus and is a Seyfert type 2 galaxy.

NGC 6015

Mark’s other two images are M13 globular cluster in Hercules, and M16, the Eagle emission nebula in Serpens Cauda.  M16 is the nebula the Hubble Space telescope targeted to produce the famous Pillars of Creation image.

M13
M16

 

Steve Norrie of Fife sent in five images of galaxies.

Two are in the constellation of Coma Berenices:  M88 and M99, taken with an ES 127mm APO refractor plus a Starlight Xpress Trius 694 mono camera and red green and blue filters to produce LRGB:

M88

M88 has an active 80 million solar mass black hole at its centre, and is a Seyfert type 2 galaxy.

M99

Steve’s remaining three images, M81 (Bode’s Galaxy), M82 and M101 (the Pinwheel galaxy), are all in Ursa Major.  They  were taken using a Celestron C9.25 SCT plus a f6.3 focal reducer with the same camera as above.  Steve included narrow band data in with the RGB for M101 (L, H alpha, RGB).   The M82 image is a combination of luminance frames and narrow band frames only (L, H alpha, OIII, SII) to offset the proximity of a gibbous moon.

M81
M82
M101

 

Dave Finnigan