Category Archives: astronomy

M106 in Canes Venatici

Field Centred at:
RA: 12h 18m 41.0s
Dec: +47° 17′ 57.3″
Field 25.2×18.9 arcmin, Up is 184° E of N

M106 (with NGC4248) - LRGBM106 (NGC 4258) is an intermediate type spiral galaxy located at a distance of 23.7 (± 1.5) million light years in the constellation of Canes Venatici. Also shown in this frame is the small spiral galaxy NGC 4248 (lower left of frame).

M106 was discovered by Pierre Méchain in 1781 and has an active nucleus and is one of the best known Type 2 Seyfert galaxies. It also is host to a water vapour megamaser that is visible in the 22GHz frequency of ortho-H20 (water molecules where the spins of the two hydrogen atoms are aligned). 

M106 also has significant hydrogen emission around the core – one of the brighter “jets” is just visible in the close up (at 150%)  – taking hydrogen alpha data would show this up to a much greater extent, but this is something that will have to follow later when skies are clear!

In June 1995, the following letter was published in Astronomy & Astrophysics from Burbidge concerning two bright Xray sources symmetrically placed about NGC 4258 (M106):  1995A&A…298L…1B

Burbidge found that these objects were in fact quasars, with redshifts of 0.39 (J1218+472) and 0.65 (J1219+473). Burbidge, who worked closely with Fred Hoyle, argues (as does Halton Arp in a later paper), that the association of these QSOs with M106 is not accidental, and that the redshifts arise from the ejection velocities of the objects from the host (pretty quick!).

All three scientists were strong proponents of non-Big Bang cosmologies though, so you may detect a slight bias here: later work (eg , http://iopscience.iop.org/article/10.1086/309327/pdf) appears to suggest one of these (J1281+472) is associated with a cluster at redshift z~0.3, and that X-Ray luminosity and cluster temperatures are entirely consistent. So, this may well be a case of line of sight.

In the field as well (see the image, left), is a further QSO with redshift ~1.04 – theory places this at around 8Gly in a flat cosmology.

 

Image was taken with an ST2000XM through a 14″ Newtonian at f4.53 (fl = 1584mm) from West Oxfordshire on Feb 13th/15th 2018. Exposures lengths are:

Lum: 5h35m (56x5m + 21x3m) 
R: 1h45m (21 x 5m, 2×2 bin)
G: 1h20m (16 x 5m, 2×2 bin)
B: 1h20m (16 x 5m, 2×2 bin)

The luminance data on its own is shown below.M106 (with NGC4248) - Luminance Channel

 

 

 

 

 

EDIT: This image was selected in 2nd place for the “A Galaxy, Far, Far Away” challenge on Stargazers Lounge – see: https://stargazerslounge.com/topic/314249-imaging-challenge-11-galaxies-winners/

Merope & Tempel’s Nebula (NGC1435)

Image centred at:
RA: 03° 46′ 18″
Dec: +23° 56′ 04″
Field of view: 25.46′ x 18.82′

Merope & NGC1435 (Tempel's Nebula)The Pleiades open cluster in Taurus is one of the brightest and most recognisable objects int he winter sky. As a first LRGB image using the 14″ Newtonian, and to test the setup of the off-axis guider, I imaged the area around Merope (23 Tau). This was also the first use of a Bahtinov mask that I got laser cut by Oxford Hackspace. The focusing mask works excellently – this should be a real plus, especially for any planetary/lunar work.

The particular area of nebulosity imaged here around Merope was discovered by Wilhelm Tempel on October 19th, 1859, and is catalogued as NGC1435. The dust isn’t in fact the nebula from which the cluster formed, rather that the Pleiades happen to be travelling through a particularly dense part of interstellar medium. This dust scatters blue light from the cluster members, resulting in the reflection nebula visible to us.

The image shows strong diffraction spikes from the secondary spider, as would be expected. There’s also further diffraction visible around the brightest stars dark shadowing present at 60 degree angles, which is the result of the mirror retaining “clips” (they are not actually clips – they are part of the cell in the case of the 9 point Orion Optics mirror cell). To remedy this would require a mask to be added over the outer edge of the mirror to cover these over – this is maybe something I’ll think about making in the future to help deal with tricky situations like this! 

The additional dark shadow pointing to the right appears to be the focuser drawtube intruding on the internal light path inside the scope – that’s probably something that can only be cured by either a shorter drawtube, or shortening the truss tubes. Again. Maybe I’ll wait in case I decide to change coma corrector at some point, in which case it’ll probably need a change to the focal plane position anyway.

The image was taken on the evening of the 7th Jan 2018 through the 14″ (350mm) Newtonian, with an ST2000XM and an MPCC v1 coma corrector. Total exposure was “only” 2h 32m (L: 59m (20x1m, 13x3m), RGB: 31m (10x1m, 7x3m) each channel). Processing in Pixinsight and Photoshop CS4.

Widefield Flaming Star and Spaghetti Nebulae

Widefield Image of The Flaming star Nebula (IC405) region in AurigaThis image was taken on 11th December which was a clear and very cold night (-8C) though skies weren’t as great as they could have been, despite the temperature. A covering of snow from a couple of days before always seems to make for much brighter skies than we’d have otherwise.

I imaged the area around the Flaming Star Neb (IC405) using my modded 350d + Canon 85mm EF combination. This image is 79x5min (6h35m total) at f4, ISO 400, taken through an IDAS P2 filter. This lens is a bit sharper at f4.5, but wanted to try and get as much signal as poss, without completely ruining the stars in the corners of the image. Reduction and processing as usual in PixInsight and Photoshop CS4. 

Widefield of Flaming Star Nebula region in Auriga - red channel, inverse
Widefield of Flaming Star Nebula region in Auriga – red channel, inverse

I offset the framing to have a go at getting the SN remnant Simeis 147, the Spaghetti nebula (Sh2-240). Bearing in mind this is a non narrowband image with an uncooled camera, I’m fairly pleased to see it there (though it is very faint!). It’s a bit clearer in the negative image of the red channel as shown (bottom right) Most definitely one for an H-Alpha filter attempt with a more suitable camera (mono, cooled, low read noise, etc.)! It would have been nice to have M37 not quite so close to the edge though…

Widefield Image of The Flaming star Nebula (IC405) region in Auriga - Annotated

There are lots of other objects in this 15°x10° view, including IC410, M36/37/38, several other Sharpless-2 objects, and dark nebulae. These are highlighted in the annotated image as shown, though there are other objects in the field of view. For example, the obscure “DU77” just to the left (north) of Simeis 147 is just visible in the colour image, and a bit clearer in the negative. 

 

Belt, Sword, Loop

An area of winter sky that surely needs little introduction. This is a widefield shot of central Orion, showing the three belt stars Alnitak, Alnilam and Mintaka and the “sword” (Orion Nebula and the Running Man Nebula). Widefield Image of Orion's belt and sword regionThe whole region is surrounded by the arc of Barnard’s Loop, a 2 million year old supernova remnant (the precursor of this was in a multiple star system and created several “runaway stars” including AE Aurigae, Mu Columbae and 53 Arietis), as well as a multitude of other nebulae and dust clouds that form part of the Orion Molecular Cloud Complex. 

Around Alnitak, the easternmost star of the belt, the Horsehead Nebula (B33) and surrounding hydrogen emission is present, as well as the slightly more orange Flame Nebula (NGC2024) to its east.

Orion's belt and sword region using 85mm lens - annotated image.Also visible is the reflection nebula complex containing M78 and further towards the top of the image is the dark nebula LDN 1622, sometimes called “The Bogeyman”. To the west (right) of the Orion Nebula is Sh2-278, with further fainter areas of nebulosity beyond this surrounding Eta Orionis. These  correspond to members of the LBN catalogue (LBN 907, 910, 915, 919, 937, 942, 945), though much more signal is needed to really get these to show well!

Image was taken on 25th/26th November 2017 from West Oxfordshire. Canon 350d (modded with Baader filter), Canon 85mm EF f1.8 USM lens (at f4.5). Image consists of 21 exposures of 5 min each at ISO 400, totalling 1h45m. Reduction and processing was performed using PixInsight and Photoshop.

Image centred at:
RA: 05h 29m 19s
Dec: +32° 29′ 10″
Field is 15° x 10°

 

Widefield Heart, Soul & Double Cluster

Image centred at:
RA: 02h 44m 19s
Dec: +61° 17′ 24″
Field is 15°x10°.
(Plate-solve by nova.astrometry.net)

Taken on the night of the 25th November 2017 from West Oxfordshire, this image is a widefield rendition of the Heart and Soul Nebulae (IC1805/Sh2-190 and IC1848/Sh2-199), which includes the Double Cluster (NGC 869 and NGC 884) in Perseus. 

Widefield image of Heart and Soul Nebulae (IC1805/Sh2-190, IC1848/Sh2-199) and Double Cluster (NGC 869 and NGC 884) and Surrounds

This was the first real test of a new widefield config that’s now driven by a Raspberry Pi 3 running KStars and Ekos under Ubuntu Mate. The RPi3 controls the camera: a Baader filter modded Canon 350d (with shutter control via a serial release cable); a Moonlite compatible, Arduino based motor focuser (with stepper driven belt drive for the lens) ; and the Losmandy GM-8 mount it all sits upon. I can remote onto the RPi using VNC to control the session as it goes, and Ekos does everything including pointing and plate-solves, camera control and autofocusing. Everything is mounted on a somewhat Heath-Robinson arrangement on a standard Losmandy dovetail (lots of velcro pads!).

Within the camera is an IDAS P2 filter – this is a multi-bandpass, light pollution suppression filter that allows for an increase in contrast between deep sky objects and the background sky levels – it isn’t a substitute for full narrowband filters, but it at least allows an improved colour rendition of the target. It’s held in an MFA (mount filter adaptor) that screws into a small hole inside the camera body, holding the filter between the EF lens and the flip mirror. 

Exposures here were 5 minutes long each at ISO400 f4.5, with 45 subframes in total – combined exposure is 3h45m. Reduction and processing took place in Pixinsight, with only a small bit of amp glow removal in Photoshop. 

Annotated widefield image of the Heart and Soul Nebulae the Double Cluster and surrounds.

An annotated image showing the position of deep sky objects, coordinates and constellation figures/boundaries is also shown. There are, however, several objects that aren’t included in the labelling here – the reflection nebula LBN 142.14+01.97 (LBN 682/Ced 14) in Camelopardalis is just visible to the left (east) of faint emission nebula Sh2-202. Open cluster Stock 2 is located (just) in Cassiopeia (to the right of the constellation label text!). And, though labelled up as SH2-191 and Sh2-197, the obscured local galaxies Maffei 1 and 2 are just visible as small, reddened smudges south of the Heart.