Avian Astronomy: Seagull Nebula

March 4, 2024 by grahamrob in AstroBin, Deep Sky Objects, Narrowband, Star Cluster and tagged astronomy, Astrophotography, deep-sky, DSO Imaging, Emission Nebula, Monoceros, Reflection Nebula | Leave a comment

Located 3,650 light-years from Earth, in the area between the Monoceros and Canis Major constellations, is the emission and reflection nebulae complex of the so-called Seagull Nebula. It’s been 8-years since I last briefly dabbled with imaging this exciting object and for good reason. From my position, this bird flies at a maximum 28^o above the southern horizon (-11 DEC) and, furthermore, spends much of its time behind houses, trees, and tall hedges, thus providing just two short windows for imaging; combined with this winter’s terrible weather it made for a tough but ultimately rewarding target.

*The Seagull’s approximate flight path seen from Fairvale Observatory makes imaging difficult*

Whilst popularly known as the Seagull Nebula, the bird consists of a number of fabulous objects spanning some 200 light-years in their entirety: the Seagull’s head (SH2-292) and wings (IC 2177), the large open star cluster along the leading edge of the left wing (NGC 2335) and a smaller cluster on the edge of the right wing (NGC 2327), the nebula at the tip of the right wing (Sh2-297), as well as many other named features (Sharpless and LBN) that are highlighted in the following plate solved image (below).

Despite the difficulties posed by the low transit of the bird in the night sky, each of the Ha, OIII and SII wavelengths are strong, making for good data acquisition and a very pleasing final SHO image.

	IMAGING DETAILS
Object	Seagull Nebula (SH2-292, IC2177 etc.)
Constellation	Monoceros
Distance	3,650 light-years
Size	Approx. 200 light-years
Apparent Magnitude	Various

Scope	William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount	SW AZ-EQ6 GT + EQASCOM computer control & Cartes du Ciel
Guiding	William Optics 50mm guide scope
	+ Starlight Xpress Lodestar X2 camera & PHD2 guiding
Camera	ZWO ASI294MM CMOS sensor
	FOV 2.87^o x 1.96^o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW	ZWOx8 EFW & 31mm Chroma Ha, OIII, SII filters
Capture & Processing	Astro Photography Tool (APT), Deep Sky Stacker & PixInsight v1.8.9-2
Image Location & Orientation	Centre = RA 07:06:42.425 DEC -11:18:53.372 Left = North Top = West
Exposures	Ha x16 + OIII x13 + SII x14 @ 600 sec Total Integration Time: 7hr 10 min
	@ Gain 120 & 30 Offset 21 @ -15^oC
Calibration	5 x 300 sec Darks 10 x NB Flats & Dark Flats @ ADU 32,000
Location & Darkness	Fairvale Observatory – Redhill – Surrey – UK Typically Bortle 5-6
Date & Time	18^th 19th January 11^th 12^th February 2023 @ +20.30h
Weather	Approx. <2^oC RH >=70% 🌙 <+55% Waning

Seeing Stars

July 9, 2023 by grahamrob in Broadband, Deep Sky Objects, General Astronomy, History, Imaging, Star Cluster and tagged Canes Venatici, Globular Clusters | Leave a comment

Of all the incredible features that constitute the Universe, located relatively close to home, I always marvel at the nature of globular clusters. Largely unknown by the lay person and myself until I took-up astronomy, more than 150 of these incredible objects orbit around the Milky Way in the form of a spherical halo both above and below the galactic disc. Between galaxy season (March – April) and the appearance of the Sagittarius arm of the Milky Way in the summer, is the globular so-called cluster season, which is heralded by the arrival of M3, one of the brightest and most popular of the clusters.

M3 was discovered by Charles Messier in 1764 but only correctly identified as a globular cluster twenty years later by William Herschel. Consisting of more than 500,000 million stars, of which at least 274 are variable stars, it is estimated to be over 11-billion years old, thus being some of the oldest stars in the Universe.

Using data gathered remotely from a Takahashi 106 FSQ situated in the dark skies of New Mexico, USA, the resulting image shows this spectacular object in all its glory. Apart from the marvellous star details within the cropped version of M3 (see top of the page), there’s also much to see and enjoy in the original widefield image (see above), that is also bountiful of colourful stars as well as several galaxies. Altogether I’m very pleased with the final image, which is probably my best globular cluster so far.

	IMAGING DETAILS
Object	M3 Globular Cluster AKA NGC 5272
Constellation	Canes Venatici
Distance	34,000 light-years
Size	18 arc minutes, which spans approx. 180 light-years
Apparent Magnitude	+6.2

Scope	Takahashi FSQ 106 FL 530mm f/5 + Moonlight Nightcrawler focuser
Mount	Paramount MyT
Guiding	Yes
Camera	QSI 683-WSG8 KAF-8300 full frame CCD sensor 5.4nm pixels
	FOV 1.94^o x 1.46^o Resolution 2.1”/pix. Image array 3326 x 2,507 pix
Processing	Deep Sky Stacker, PixInsight v1.8.9-1
Image Location & Orientation	Centre – RA 13:42:12.768 DEC +28:23:5.03
Exposures	L x12, R x12, G x19, B x12 x 300 secs @ -20C Total Integration Time: 4hr 35min
Calibration	30 x 300 secs Darks x56 Bias & x20 LRGB Flats
Location & Darkness	Deep Sky West – amateur hosting facility near Rowe, New Mexico – USA SQM Typically >= 21.7
Date & Time	May 2018

The Unicorn’s Finger

March 14, 2023 by grahamrob in Deep Sky Objects, Narrowband, Nebula, Star Cluster and tagged Monoceros | Leave a comment

SH2-284 is an HII star forming region of dust and gases, sculpted by the radiation and interstellar winds emanating from the young (3 to 4 million years) open star cluster Dolidze 35 located near its centre. Along the inner edge of the main ring structure are numerous dark dust pillars and Bok Globules, not unlike those of the Elephant’s Trunk nebula, of which the largest seems to resemble a hand with a large bony finger at the end pointing inwards (see cropped + rotated image below).

Despite its close resemblance to the Elephant’s Trunk and the nearby Rosette nebula, the emission nebula SH2-284 is by comparison somewhat overlooked. Being some x8 times further away it’s apparent size is a good deal smaller and much fainter in nature but still forms an excellent late winter image target.

	IMAGING DETAILS
Object	SH2-284 or LBN 983
Constellation	Monoceros
Distance	18,000 light-years
Size	0.50^o
Apparent Magnitude	Faint

Scope	William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount	SW AZ-EQ6 GT + EQASCOM computer control & Cartes du Ciel
Guiding	William Optics 50mm guide scope
	+ Starlight Xpress Lodestar X2 camera & PHD2 guiding
Camera	ZWO ASI294MM CMOS sensor
	FOV 2.87^o x 1.96^o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW	ZWOx8 EFW & 31mm Chroma LRGB filters
Capture & Processing	Astro Photography Tool + PHD2 + PixInsight v1.8.9-1
Image Location & Orientation	Centre = RA 06:45:20.506 DEC +00:18:12.758 Right = North Top = East
Exposures	Ha 53 x 300 sec, OIII 36 x 300 sec, SII 36 x 300sec = 11hr 30 min R 35 x 60 sec, G 35 x 35 sec, B 34 x 60 sec = 1hr 44min Total Integration Time: 13hr 14 min
	@ 120 Gain 30 Offset @ -15^oC
Calibration	5 x 300 sec & 20 x 60 sec Darks + 15 x LRGB & Ha, OIII, SII Flats & Flat Darks @ ADU 32,000
Location & Darkness	Fairvale Observatory – Redhill – Surrey – UK Typically Bortle 5-6
Date & Time	6th^th + 7^th + 8^th + 9^th + 13^th February 2023 @ +19.30h
Weather	Approx. <=3^oC RH >=70% 🌙 Full Moon – waning

2021 The Year In Pictures

January 1, 2022 by grahamrob in AstroBin, Broadband, Dark Nebula, Deep Sky Objects, Galaxy, General Astronomy, Globular Cluster, Imaging, Narrowband, Nebula, Processing, Star Cluster, Supernova, Widefield Imaging and tagged Astrophotography, DSO Imaging | Leave a comment

Every year since 2014 I’ve published a retrospective blog of my astrophotgraphy year just ending called Reflections. It’s been a useful task that enables me to bring together the best and sometimes the worst of my images, in order to consider the good and bad points + progress made + set some objectives for the coming year. Eight years on, after which I believe I’ve now reached at least a respectable level of imaging and processing, I’ve decided to stop this format for the time being.

Notwithstanding, at this time of the year I also produce an astrophotography calendar for members of my family, which consists of the better images from the year just ending; I think they like them and certainly all use the calendar during the coming year. Moreover, I also recently started to compile a video of the said calendar images set to appropriate music, which we all watch together prior to seeing the actual calendar. It’s a great way to present the images, which look really stunning on today’s large Smart TV’s and is fun to watch with the family too.

The video for this last year 2021 can be viewed on YouTube HERE and below is a brief very general overview of each image. More detailed background information and imaging details for those interested can be found in relevant blogs posted on this site during the past year.

2022 CALENDAR

A new set of filters, improved processing techniques and access to data from a telescope at a dark sky site in New Mexico, USA (shown by an asterisk *) contributed to an exciting astrophotography year in 2021.

FRONT COVER	The Carnival of Animals: Special processing of the inner region of the Rosette Nebula highlights the ‘animals’ or Bok Globules – clouds of dust undergoing gravitational collapse as part of the process of new star formation.
JANUARY	LDN-1250 Dark Nebula*: Dark or absorption nebulae are a type of interstellar cloud which are so dense they obscure or absorb visible light emitted from objects behind or within and thereby contrast with the general light flux of the Universe as dark areas.
FEBRUARY	CTB-1 Supernova Remnant*: The overall structure of this supernova remnant is that of a circular shell, with a conspicuous rupture towards the north (lower right of image). The main red Ha-shell is composed of multiple interlocking filament limbs, with a blue / green OIII arc along one side.
MARCH	Jellyfish Nebula: Locatedin the Gemini constellation some 5,000 light years from Earth, this is a remnant of a supernova that took place during the past 30,000 years. With a diameter of 70 light-years, the object is visually speaking nearly twice the size of a full moon.
APRIL	Markarian’s Chain: The Virgo cluster consists of more than 2,000 galaxies, within which Markarian’s Chain forms a J-curve string of bright galaxies that share a common motion through space.
MAY	*M13 Great Globular Cluster of Hercules:** Consisting of several hundred thousand stars and 145 light-years in diameter, M13 is considered to be the finest cluster in the Northern Hemisphere.
JUNE	*Cave Nebula**: Located along the plane of the Milky Way is the diffuse emission nebula referred to as the Cave Nebula. The Cave at the centre is critically located at the boundary of the Cepheus molecular cloud and the hot, young stars which ionize the surrounding gases to great effect.
JULY	Orion Widefield: Framed around the area of Orion’s Belt, the Horsehead Nebula and the Great Orion Nebula, look hard and the refection nebula M78 can also be seen in the lower left corner.
AUGUST	*Elephant’s Trunk Nebula**: A very large emission nebula, the so-called Elephant’s Trunk Nebula is rightly viewed as one of astrophotography’s most iconic images. The ‘trunk’ itself dominates the centre of this image and is illuminated from behind by a bright star forming region.
SEPTEMBER	M31 Andromeda Galaxy: The full benefit of new filters, improved guiding, clear skies over 6-nights and extensive use of new processing techniques can be seen in my best image yet of Andromeda.
OCTOBER	Butterfly Nebula: Situatedwithin the Orion Arm of the Milky Way is the Gamma Cygni nebula, a diffuse emission nebula surrounding the star Sadr. Either side of the dark rift which divides the image from top to bottom are two large bright areas that together form the so-called Butterfly.
NOVEMBER	M33 Triangulum Galaxy: Like it’s neighbour Andromeda, better data and processing has produced an exciting new image of M33 this year, the red areas highlight Ha-rich star-forming regions
DECEMBER	Flying Bat & Giant Squid Nebula*: This very faint OIII emission nebula Ou4 required an imaging time of 40-hours. For obvious reasons Ou4 has become known as the Giant Squid Nebula which, moreover, lies within the much larger SH2-129 HII emission region or the Flying Bat Nebula.

HAPPY NEW YEAR + CLEAR SKIES IN 2022

Reach For The Stars

December 21, 2021 by grahamrob in Broadband, Deep Sky Objects, Imaging, Software, Star Cluster and tagged M45, Orion Constellation, Pleiades, Taurus Constellation | Leave a comment

Preceding the arrival of what is for many astronomers the highlight of the year, the Orion constellation and all it’s objects, is the appearance of the majestic Pleiades open star cluster (Messier 45) in the constellation of Taurus. The so-called Seven Sisters consists of hot blue luminous stars that formed during the past 100 million years, which are expected to last another 250 million years and can be easily observed with the naked eye even here at Fairvale Observatory (Bortle 5/6).

I have imaged this exciting star cluster before but with astrophotography and especially iconic objects such as the Pleiades, one is always drawn back for another try. Now armed with Chroma filters and a growing list of PixInsight skills acquired since last imaged late in 2018, I wanted to tease out more details of the fine wispy dust cloud through which the Sisters are passing and forms the signature of all good Pleiades’ images. Furthermore, with longer exposures and total integration time greater than before, maybe I could also capture something of the abundant interstellar dust that is present across the wider background?

I am therefore very pleased that the final image (top of the page + cropped version above) which has more than achieved these objectives and marks a significant improvement on my previous attempts – it’s always worth trying that little bit more.

	IMAGING DETAILS
Object	M45 The Pleiades AKA Seven Sisters
Constellation	Taurus
Distance	444 light-years
Size	110’
Apparent Magnitude	+1.6

Scope	William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount	SW AZ-EQ6 GT + EQASCOM computer control
Guiding	William Optics 50mm guide scope
	+ Starlight Xpress Lodestar X2 guide camera & PHD2 control
Camera	ZWO1600MM-Cool (mono) CMOS sensor
	FOV 2.65^o x 2.0^o Resolution 2.05”/pix Max. image size 4,656 x 3,520 pix
EFW	ZWO x8 EFW & Chroma 31mm LRGB filters
Capture & Processing	Astro Photography Tool + Deep Sky Stacker PixInsight v 1.8.8-11, Photoshop CS3, Topaz AI Denoise
Image Location & Orientation	Centre: RA 03:47:03 DEC 24:03:08 Top = North Right = West
Exposures	12 x 300 sec LRGB Total time: 4 hours
	@ 139 Gain 21 Offset @ -20^oC
Calibration	5 x 300 sec Darks 15 x Flats & Dark Flats LRGB @ ADU 25,000
Location & Darkness	Fairvale Observatory – Redhill – Surrey – UK Typically Bortle 5
Date & Time	6^th December 2021 @ +19.15h
Weather & Moon	Approx. <=4^oC RH >=85% 🌙 New Moon