Messier 101 The Pinwheel Galaxy

 Moon was gibbous so pretty bright. Nice clear night though.

L: 3hrs 17 min , 102 x 114s, 139 gain, 1x1

RGB: around an hour each, 30 x 114s, 139 gain, 1x1

Wikipedia:M101 is a large galaxy, with a diameter of 170,000 light-years. By comparison, the Milky Way has a diameter of 100,000 light-years. It has around a trillion stars, twice the number in the Milky Way. It has a disk mass on the order of 100 billion solar masses, along with a small central bulge of about 3 billion solar masses. Its characteristics can be compared to those of Andromeda Galaxy.

M101 has a high population of H II regions, many of which are very large and bright. H II regions usually accompany the enormous clouds of high density molecular hydrogen gas contracting under their own gravitational force where stars form. H II regions are ionized by large numbers of extremely bright and hot young stars; those in M101 are capable of creating hot superbubbles. In a 1990 study, 1264 H II regions were cataloged in the galaxy. Three are prominent enough to receive New General Catalogue numbers—NGC 5461, NGC 5462, and NGC 5471.

M101 is asymmetrical due to the tidal forces from interactions with its companion galaxies. These gravitational interactions compress interstellar hydrogen gas, which then triggers strong star formation activity in M101's spiral arms that can be detected in ultraviolet images.

NGC 5906/5907 The Splinter Galaxy

 These images were captured on 17th April, the last ones using my old Bahtinov mask. The sky went very murky around midnight, hence the abbreviated data.

L: 34 x 114 s (1 hr), 139 gain, 1x1

RGB: approx 11 x 114 (20mins), 139 gain, 1x1

Wikipedia: NGC 5907 (also known as Knife Edge Galaxy or Splinter Galaxy) is a spiral galaxy located approximately 50 million light years from Earth. It has an anomalously low metallicity and few detectable giant stars, being apparently composed almost entirely of dwarf stars.It is a member of the NGC 5866 Group.

NGC 5907 has long been considered a prototypical example of a warped spiral in relative isolation. In 2006, an international team of astronomers announced the presence of an extended tidal stream surrounding the galaxy that challenges this picture and suggests the gravitational perturbations induced by the stream progenitor may be the cause for the warp.

NGC 5907 is also known as NGC 5906. This second NGC number refers to a fainter part of the galaxy lying west of the dust lane that was recorded by astronomer and physicist George Johnstone Stoney on April 13, 1850.

NGC 5866 The Spindle Galaxy

 

I have bought a new bahtinov mask in order to try and improve the focus. The mask was 3D printed and has finer slits than my old (home made) one. The diffracted image of the star was definitely sharper and I was able to get a point of focus where the value wobbled around  the 'in focus' value.

L : 74 x 114 s (2hrs 20min) , 139 gain, 1x1

R: 23 x 114 s (41min), 139 gain, 1x1

G:23 x 114 s (41min), 139 gain, 1x1

B:25 x 114 s (45min), 139 gain, 1x1

Wikipedia:

NGC 5866 (also called the Spindle Galaxy or Messier 102) is a relatively bright lenticular galaxy in the constellation Draco. NGC 5866 was most likely discovered by Pierre Méchain or Charles Messier in 1781, and independently found by William Herschel in 1788. Measured orbital velocities of its globular cluster system[5] imply that dark matter makes up only 34±45% of the mass within 5 effective radii; a notable paucity.

One of the most outstanding features of NGC 5866 is the extended dust disk, which is seen almost exactly edge-on. This dust lane is highly unusual for a lenticular galaxy. The dust in most lenticular galaxies is generally found only near the nucleus and generally follows the light profile of the galaxies' bulges. This dust disk may contain a ring-like structure, although the shape of this structure is difficult to determine given the edge-on orientation of the galaxy. It is also possible that the galaxy is a spiral galaxy that was misclassified as a lenticular galaxy because of its edge-on orientation, in which case the dust lane would not be too unusual.

NGC 5866 is one of the brightest galaxies in the NGC 5866 Group, a small galaxy group that also includes the spiral galaxies NGC 5879 and NGC 5907. This group may actually be a subclump at the northwest end of a large, elongated structure that comprises the M51 Group and the M101 Group, although most sources distinguish the three groups as separate entities.

The Hairy Eyebrow Galaxy, NGC 4526 and M98

 These were imaged across two nights, trying ot get subs from 9pm till 5 am on both. Usual settings, with L being 3 times the total for RG and B, all at 1x1, bias 139 and 114s subs. 

NGC 4526 L:3hr 11 min  RGB around 1 hr

M98 : L 3hr 27 min  RGB around 1hr 10 min

          104 x 114 s

The main difference from recent images is that I have added a focal corrector again, so instead of being at F10, the scope is at F6.3, images should be flatter with less coma and a larger FOV.

Wikipedia: NGC 4526 (also listed as NGC 4560) is a lenticular galaxy located approximately 55 million light-years from the Solar System in the Virgo constellation and discovered on 13 April 1784 by William Herschel.

The galaxy is seen nearly edge-on. The morphological classification is SAB(s)0°,which indicates a lenticular structure with a weak bar across the center and pure spiral arms without a ring. It belongs to the Virgo cluster and is one of the brightest known lenticular galaxies.

The inner nucleus of this galaxy displays a rise in stellar orbital motion that indicates the presence of a central dark mass. The best fit model for the motion of molecular gas in the core region suggests there is a supermassive black hole with about 4.5+4.2−3.0×108 (450 million) times the mass of the Sun. This is the first object to have its black-hole mass estimated by measuring the rotation of gas molecules around its centre with an Astronomical interferometer (in this case the Combined Array for Research in Millimeter-wave Astronomy).

Wikipedia: Messier 98, M98 or NGC 4192, is an intermediate spiral galaxy about 44.4 million light-years away in slightly northerly Coma Berenices, about 6° to the east of the bright star Denebola (Beta Leonis). It was discovered by French astronomer Pierre Méchain on 1781, along with nearby M99 and M100, and was catalogued by compatriot Charles Messier 29 days later in his Catalogue des Nébuleuses & des amas d'Étoiles. It has a blueshift, denoting ignoring of its fast other movement (vectors of proper motion), it is approaching at about 140 km/s.

The morphological classification of this galaxy is SAB(s)ab, which indicates it is a spiral galaxy that displays mixed barred and non-barred features with intermediate to tightly wound arms and no ring. It is highly inclined to the line of sight at an angle of 74° and has a maximum rotation velocity of 236 km/s.The combined mass of the stars in this galaxy is an estimated 76 billion (7.6 × 1010) times the mass of the Sun. It contains about 4.3 billion solar masses of neutral hydrogen and 85 million solar masses in dust. The nucleus is active, displaying characteristics of a "transition" type object. That is, it shows properties of a LINER-type galaxy intermixed with an H II region around the nucleus.

NGC 4216 in Virgo

 The weather  forecast was dry overnight so I had a go at collecting data from Dusk till dawn. I collected around 3 hours in L, and an hour each in R, g and B. Lost quite a lot of frames to poor guiding in the early stage, plus  DSS rejected a few too. Subs were 115 s at a gain of 139, all at 1x1.

Wikipedia: NGC 4216 is one of the largest and brightest spiral galaxies of the Virgo Cluster, with an absolute magnitude that has been estimated to be −22 (i.e.: brighter than the Andromeda Galaxy), and like most spiral galaxies of this cluster shows a deficiency of neutral hydrogen that's concentrated within the galaxy's optical disk and has a low surface density for a galaxy of its type. This explains why NGC 4216 is considered an anaemic galaxy by some authors, also with a low star formation activity for a galaxy of its type.[5] In fact, the galaxy's disk shows pillar-like structures that may have been caused by interactions with the intracluster medium of Virgo and/or with nearby galaxies.

In NGC 4216's halo, besides a rich system of globular clusters with a number of them estimated in around 700 (nearly five times more than the Milky Way), two stellar streams that are interpreted as two satellite galaxies being disrupted and absorbed by this galaxy are present.

NGC 4216 seems to be in a place of the Virgo cluster where dwarf galaxies are being destroyed/accreted at a high rate, with it suffering many interactions with these type of galaxies.

Messier 46 and a Planetary Nebula

 Over a couple of nights I have used the camera as an enhanced eye, looking at all sorts of objects (Messier objects, open  clusters, galaxies, etc.). One that I had not seen before and took my fancy for a photo target was MEssier 46, which has in the space between us and it, a planetary nebula.

As my usual, not enough subs, especially in colour (8 min or thereabouts), plus 30 in L.

Wikpedia: Messier 46 or M46, also known as NGC 2437, is an open cluster of stars in the slightly southern constellation of Puppis. It was discovered by Charles Messier in 1771. Dreyer described it as "very bright, very rich, very large." It is about 5,000 light-years away. There are an estimated 500 stars in the cluster with a combined mass of 453 M☉, and it is thought to be a mid-range estimate of 251.2 million years old.

The planetary nebula NGC 2438 appears to lie within the cluster near its northern edge, but it is most likely unrelated since it does not share the cluster's radial velocity.