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ngc 253 John Herschel in South Africa ( NGC 253, Sculptor Galaxy )
MikeODay posted a blog entry in The Sculptor Galaxy - NGC 253
Sir John Herschel at the Cape of Good Hope Having spent the years 1825 to 1833 cataloguing the double stars, nebulae and clusters of stars visible from Slough, in the south of England, John Herschel, together with his family and telescopes, set sail from Portsmouth on the 13th of November 1833 bound for Cape Town. As detailed below, in an extract from his book, the family enjoyed a pleasant and uneventful voyage and arrived some 5 months later at Table Bay with all family and instruments in good condition. Reading on however, one might very well think that it might not have ended so well had they but left shortly after ... “... (iii.) Accordingly, having- placed the instrument in question, as well as an equatorially mounted achromatic telescope of five inches aperture, and seven feet focal length, by Tulley, which had served me for the measurement of double stars in England; together with such other astronomical apparatus as I possessed, in a fitting condition for the work, and taken every precaution, by secure packing, to insure their safe arrival in an effective state, at their destination, they were conveyed (principally by water carriage) to London, and there shipped on board the Mount Stewart Elpliinstone, an East India Company's ship, Richardson,Esq. Commander, in which, having taken passage for myself and family for the Cape of Good Hope, we joined company at Portsmouth, and sailing thence on the13th November, 1833, arrived, by the blessing of Providence, safely in Table Bay, on the 15th January, 1834, and landed the next morning, after a pleasant voyage, diversified by few nautical incidents, and without seeing land in the interim. It was most fortunate that, availing himself of a very brief opportunity afforded by a favorable change of wind, our captain put to sea when he did, as we subsequently heard that, immediately after our leaving Portsmouth, and getting out to sea, an awful hurricane had occurred from the S. W. (of which we experienced nothing), followed by a series of south-west gales, which prevented any vessel sailing for six weeks. In effect, the first arrival from England, after our own, was that of the Claudine, on the 4th of April, with letters dated January 1st.(iv.) ...” “Result of Astronomical Observations, Made During the Years 1834, 5, 6, 7, 8, At the Cape of Good Hope ... “ by Sir John Herschel, 1847 John Herschel rented a property and set up the twenty foot reflector near Table Mountain, at a site, that was then, just outside of Cape Town. The Twenty Feet Reflector at Feldhausen, Cape of Good Hope, South Africa, 1834 This telescope was made by Herschel in England and transported, along with his other instruments, by ship to Cape Town and then inland to Feldhausen. The telescope is a Newtonian reflector, built to William Herschel’s design, with a focal length of 20 feet and clear aperture of 18 1/4 inches ( f13 ). The location of the telescope was established by careful survey to be: lat 33d 55’ 56.55”, long 22h 46’ 9.11” W ( or 18.462 deg E ). The site of the great telescope was memorialised by the people of Cape Town by the erection of a granite column that is still there today. ............. Observations of the Sculptor Galaxy Amongst his many thousands of observations made from Cape Town, of nebulae, clusters of stars, double stars, the sun, etc., Sir John Herschel records that he observed V.1 ( CH10 - Caroline’s Nebula - the Sculptor Galaxy ) during two different “sweeps” and gave it the number 2345 in his South African catalogue. Sweeps: 646 - 20th November 1835; 733 - 12th September 1836 At the latitude of Feldhausen, and on these dates, the Sculptor galaxy would have been at an altitude around 80 degrees above the northern horizon when near the meridian ( which was where the telescope was pointed during Herschel’s “sweeps” ). The sight afforded from this location, with the Sculptor Galaxy almost at the zenith, must have been significantly brighter and clearer than the Herschels had thus far been granted from its location way down near the horizon south of Slough. .......... Other Obsevations by John Herschel from Cape Town Also observed by John Herschel in 1835 were the people and animals that inhabit the moon ... The Great Moon Hoax of 1825 - “Lunar Animals and other Objects, Discovered by Sir John Herschel in his Observatory at the Cape of Good Hope ... “ -
Observations of the Sculptor Galaxy ( NGC 253 ) by William and John Herschel ......... Part 2. Observations of "Caroline's Galaxy" by Sir John Herschel, 1830's Sir John Herschel, the only child of Mary Baldwin and Sir William Herschel, was born in 1792 when his father was in middle age and already famous as one of world's leading astronomers. Having excelled in school, and no doubt inspired by his famous elders, John Herschel decided upon a career as a 'man of science' and set out to pursue a wide range of interests; with one particular focus being a continuation of the study of the heavens commenced by his father and aunt, Caroline Herschel. In 1820, with the assistance of his father, John Herschel supervised the construction of a new telescope at Slough in England. As described in the extract below ( from a paper presented to the Royal Society in 1826, titled "Account of some observations made with a 20-feet reflecting telescope ... " ), the telescope had a polished metal mirror with clear aperture of 18 inches, focal length of 20 feet and was modelled on the same design created by his father. It is this telescope, in the 1820’s and early 30’s, following the death of his father and the return of his aunt Caroline to Hanover, that John Herschel used to 'sweep' the night sky and extend the catalogue of nebulae and clusters of stars that was published by his father ( see W. Herschel's Catalogue of One Thousand new Nebulae and Clusters of Stars ). On the 1st of July 1833, having complied sufficient observations, John Herschel presented to the Royal Society an updated list of the positions and descriptions of the Nebulae and Clusters of Stars that he had thus far observed. As noted in the introduction to the paper published in the Philosophical Transactions, he had planned to wait before publishing until he had complied a fully comprehensive general catalogue of objects visible from the south of England. However, due to his expectation of “several more more years additional work” needed to complete the task and his assessment that he now was in a position to address, at least in part, the then current “... want of an extensive list of nebulae arranged in order of right ascension ...”, he elected to present his list, “ ... simply stating the individual results of such observations as I have hitherto made ... “. It was not until October 16, 1863, some thirty years later, that Sir John would deliver to the Royal Society his General Catalogue of Nebulae and Clusters of Stars. As well as introducing many objects that had not previously been recorded, Sir John’s list of 1833 included a re-examination of, and in some cases a small correction to, the positions of many of the deep sky objects observed by his father and noted down by his aunt. One of these re-visited objects was, unsurprisingly, the large and bright nebula discovered by Caroline Herschel in 1783 and recorded in Sir Williams’s catalogue as V.1 / CH 10 ( object number one, of class five ( very large nebulae ) / Caroline Herschel #10 ). In total, John Herschel records around 2500 observations of nebulae and clusters of stars in his 1833 paper; with observation #61 being V.1, the “ Sculptor Galaxy “ . The measured position of V.1is given in RA and the angle from the north celestial pole ( all reduced to epoch 1830.0 ). The description can be interpreted by reference to the legend in the paper. Thus, “ A vL mE vB neb “ becomes “ A very large, much extended, elliptic or elongated, very bright nebula “. He also notes that in addition to this observation, #61, noted down from sweep #306, V.1 was also observed in sweep #292, “but no place was taken”. The figure to which he refers , figure 52, is included towards the back of his paper and is a sketch he made of the Sculptor Galaxy. to be continued ...
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Observations of the Sculptor Galaxy ( NGC 253 ) by William and John Herschel The very large and bright 'nebula' discovered by Caroline Herschel in 1783, that we now know as the Sculptor Galaxy, was observed a number of times by her 'dear brother' Sir William Herschel and by her 'beloved nephew' Sir John Herschel, Baronet. Some of these observations were recorded and published in the Philosophical Transactions of the Royal Society and, with respect to those by Sir John in South Africa, in the book of Astronomical Observations at the Cape of Good Hope. ......... Part 1. Observation of the 'class V nebula', H V.1, by Sir William Herschel, 1783 In 1782, with the fresh patronage of King George III, William Herschel, together with his sister Caroline, undertook the not inconsiderable task of transferring his astronomical equipment from Bath to Datchet ( near Windsor ) in England. Shortly afterwards, in 1983, Sir William began a "sweep of the heavens" with the very large Newtonian telescope of his design and construction. With this mighty telescope's twenty foot focal length and clear aperture of a little over eighteen and half inches, William was able to see fainter objects and smaller detail than any other astronomer of that time. ( source: The Scientific Papers of Sir William Herschel, Vol.1 ) ...... On the 30th of October, 1783, in the course of one of his "sweeps" with the twenty-foot telescope, Sir William Herschel observed Caroline's 'nebula' and noted down ( or perhaps more likely, dictated to Caroline ) a description of what he saw and a reference to its position relative to a 4th magnitude star in the Piscis Austrainus constellation, #18 Pis. Aust. ( with reference to Flamsteed's Catalogue ( or HD 214748 , HIP 111954 as we might call it )). Over the course of the next three years, Sir William would go on to view the Sculptor Galaxy a total of seven more times; as recorded in his paper "Catalogue of One Thousand New Nebulae and Clusters of Stars", presented to the Royal Society on the 27th of April 1786. ( Source ) Sir William's somewhat cryptic notes can be translated by reference to the key provide in his paper and doing so reveals the following: Class: V. ( very large nebula ) Number: 1 Observed ( by WH ): 30 Oct 1784 Reference star: 18 Piscis Austrainus ( Flamsteed's Catalogue; the best reference for the time - we might use epsilon Pis. Aust. or HD 214748 / HIP 111954 ) Sidereal direction rel. to star ( following or leading ): following star Sidereal time rel. to star: 128 min 17 sec Declination direction rel. to star: north of star Declination amount rel. to star: 1deg 39min Observed: 8 times ( up until April 1786, the date of the paper ) Description: - cB: "confidently bright" - mE: "much extended" - sp: "south preceding" - nf: "north following" - mbM: "much brighter middle" - size: 50' x 7 or 8' " CH" denotes that it was discovered by his sister Caroline Herschel The note he refers to expands on details of Caroline's discovery ... ...............................................
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The Jewel Box ( NGC 4755 ) is an open cluster of mostly hot young blue-white stars that appears to the unaided eye as a bright 4th magnitude star close to the Southern Cross. Only visible from southern latitudes, the Jewel Box was first recorded by Nicolas Louis de Lacaille during his visit to South Africa in 1751 and was later described by Sir John Herschel as "a casket of variously coloured precious stones" - hence the name "Jewel Box". The Jewel Box open star cluster ( ngc 4755 ) in Curx ( please click / tap on image to see larger and sharper ) Please see here for image details.
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Also known as the Theta Carinae Cluster, The Southen Pleiades is a very bright open cluster in the Carina constellation. It was discovered by Abbe Lacaille during his visit to South Africa in 1752. Containing around 60 stars, IC 2602 shines with an overall magnitude of 1.9 and its brightest member is Theta Carinae with a visual magnitude of 2.7. This cluster of young blue stars is relatively close to us at "only" 479 light years. 5 May 2018 The Southern Pleiades open star cluster ( IC 2602 ) in Carina ( please click / tap on image to see larger and sharper ) Image details can be found here.
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Took this photo of the milkyway last week at the Namibian Kalahari desert. https://www.flickr.com/photos/101543943@N04/48039046618/in/dateposted/ Thanks for watching, Haim My Flicker Page: https://www.flickr.com/photos/101543943@N04/
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It looks like I may be spending a week on a farm in South Africa in mid to late June. The farm also operates as a Cheetah sanctuary and I will be volunteering as a feeder, walker and mucker outer of various big cats etc. The evenings are my own and the skies get pretty damn dark I have a set of 10 X 21 bins but am hoping to borrow some a little more powerful. What should I be trying to find in the skies? Cheers.
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Astrophotography Scrapbook Vol. 1 Cover Page Lagoon Nebula in Sagittarius ( Messier 8, NGC 6523 ) The Fighting Dragons of Ara ( NGC 6188 ) War and Peace in Scorpius ( NGC 6357 ) Spiral Galaxy NGC 6744 in Pavo Ptolemy's Cluster in Scorpius ( Messier 7, NGC 6475 ) A Million Stars in the Deep South ( NGC 104, 47 Tucanae ) A Wishing Well in Carina ( NGC 3532 ) A Beehive in the Southern Sky ( NGC 2516 ) The Sliver Coin in Sculptor ( NGC 253 ) The Great Nebula in Orion ( Messier 42, NGC 1976 ) A Cluster of Pearls in Centaurus ( NGC 3766 ) - new 5 Dec resources: Scrapbook Template ------------------------------------- When I show my astrophotography images to my friends and family they invariably want to know what they are looking at. This led me to wonder if there was a way I could display my images on a single page together with a few notes on the target object as well as few technical details of the capture for those who might be interested. What I came up with a "scrapbook" like page that combines all of these three elements in a single PDF sheet ( or jpeg image) that ultimately I might combine together to form a PDF book that I can share online or send to friends and family. In the meantime, I thought I might post in this thread each page of my work-in-progress towards volume 1 of my Astrophotography Scrapbook. Any and all comments, observations, suggestions and constructive criticisms will be warmly received. Cheers Mike ps. The pages have been sized to fit full screen on an IPAD
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The Southern Beehive Cluster ( NGC 2516 ) in the constellation Carina - by Mike O'Day ( 500px.com/MikeODay ). Because of its similarity to the “The Beehive Cluster” ( catalogued as M44 by Messier ), NGC 2516, which is only visible from lower latitudes, has become known as the “Southern Beehive Cluster”. At a distance of around 1300 light years, NGC 2516 is relatively close to us and resides in the same spiral arm of the Milkyway as we do. Containing around 100 stars, with a number of them in the magnitude 5 to 6 range, NGC 2516 has an apparent magnitude of 3.8 and is visible to the naked eye as a small bright hazy patch at the edge of the Milkyway. Links: https://500px.com/MikeODay http://photo.net/photos/MikeODay Details: centre of image: RA 7h 58.4m, Dec -60 deg 41.9' (nova.astrometry.net) Field of view (arc min): 78.9 x 52.6 Scale of image: 2.18 arcsec / pixel Up direction in image is North Skywatcher Quattro 10" f4 Newtonian telescope Skywatcher AZ Eq6 GT Mount Guiding: Orion Shortube 80 guidescope, Starshoot Autoguider, PHD2 guiding RA only Baader MPCC Mark 3 Coma Corrector Hutech IDAS D1 light pollution filter Nikon D5300 (unmodified) Long exposure noise reduction on Stack of 14 x 360sec images @ ISO400 Pixinsight. Taken from the Blue Mountains above Sydney Australia over two nights: 29th and 30th March 2016
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The Southern Beehive Cluster ( NGC 2516 ) in the constellation Carina re-processed ( improved colour balance, more colour in the smaller stars and lower saturation overall ): previous version: ( click on image to see larger ) Because of its similarity M44, NGC 2516, which is only visible from lower latitudes, has become known as the Southern Beehive Cluster. At a distance of around 1300 light years, NGC 2516 is relatively close to us and resides in the same spiral arm of the Milkyway as we do. Containing around 100 stars, with a number of them in the magnitude 5 to 6 range, NGC 2516 has an apparent magnitude of 3.8 and is visible to the naked eye as a small bright hazy patch at the edge of the Milkyway. Details: RA 7h 58.4m, Dec -60 deg 41.9' Skywatcher Quattro 10" f4 Newtonian telescope Skywatcher AZ Eq6 GT Mount. Guiding: Orion Shortube 80 guidescope, Starshoot Autoguider, PHD2, guiding RA only Baader MPCC Mark 3 Coma Corrector. Hutech IDAS D1 light pollution filter Nikon D5300 (unmodified) Long exposure noise reduction on Stack of 14 x 360sec images @ ISO400 Pixinsight
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21st April: Re-processed to better show the colour of the fainter stars ... ....... Shimmering like a pearl to the naked eye, this open cluster of mostly young blue stars ( known as the "Pearl Cluster" ) is approximately 5500 light years from Earth and was discovered by Abbe Lacaille in 1752 from South Africa. This HDR image is constructed from 11 sets of exposures ranging from 1/4 sec ( to capture the centre of the brighter stars ) through to 240 seconds ( for the fainter stars of the Milky Way ). Total exposure time was around 5 hours. A Cluster of Pearls in the Southern Skies ( NGC 3766 " The Pearl Cluster" ) ( please click / tap on image to see larger and sharper - a full size image can be found here ) 12 April 2018 ..... Image details: Field of view ..... 58' 49.8" x 39' 36.4" Image center ...... RA: 11 36 03.890 Dec: -61 35 30.17 Resolution ........ 0.586 arcsec/px ( full size image ) Orientation: North is up Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture : 1470mm f4.7 Mount: Skywatcher EQ8 Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.91um pixels) Location: Blue Mountains, Australia Moderate light pollution ( pale green zone on darksitefinder.com map ) Capture ( 12 April 2018 ): 11 sets of sub-images with exposure duration for each set doubling ( 1/4s to 240s ) all at ISO250. ( 70 x 240sec + 10 each forthe other durations ) Processing: Calibration: master bias, master flat and master dark Integration in 11 sets HDR combination Pixinsight April 2018
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Also known as the Theta Carinae Cluster, The Southen Pleiades is a very bright open cluster in the Carina constellation. It was discovered by Abbe Lacaille during his visit to South Africa in 1752. Containing around 60 stars, IC 2602 shines with an overall magnitude of 1.9 and its brightest member is Theta Carinae with a visual magnitude of 2.7. This cluster of young blue stars is relatively close to us at "only" 479 light years. 5 May 2018 The Southern Pleiades ( IC 2602 ) in Carina ( please click / tap on image to see larger and sharper ) ......... Image details: Orientation: North is up Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture : 1470mm f4.7 Mount: Skywatcher EQ8 Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.91um pixels) Location: Blue Mountains, Australia Moderate light pollution ( pale green zone on darksitefinder.com map ) Capture ( 5 May 2018 ): 14 sets of sub-images with exposure duration for each set doubling ( 1/30th sec to 240 sec ) all at ISO250. ( 22 x 240sec + at least 10 each forthe other durations ) Processing: Calibration: master bias, master flat and master dark Integration in 14 sets HDR combination Pixinsight May 2018
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Barred Spiral Galaxy NGC 6744 in Pavo NGC 6744 is a Milky Way like barred spiral galaxy in the constellation Pavo. Visible only from lower latitudes, the light we see now left this galaxy around 30 million years ago. Details: Spiral Galaxy NGC 6744 in Pavo. Skywatcher Quattro 10" f4 Newtonian telescope. Skywatcher AZ Eq6 GT Mount. Orion 80mm f5 guide scope and auto guider - PHD2. Baader MPCC Mark 3 Coma Corrector, no filter. Nikon D5300 (unmodified). Field of view (deg) ~ 1.35 x 0.90. ISO800, 14bit NEF, Long Exp. NR on. 44 x 120sec 4th Sept 2016 Processed in PixInsight and finished off in Photoshop. Links: https://500px.com/MikeODay http://photo.net/photos/MikeODay
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The Southern Pinwheel Galaxy ( Messier 83, NGC 5236 ) in the constellation Hydra. ( click on image to see fuill size ) Messier 83 is a relatively large and bright spiral galaxy visible from southern and mid latitudes. Clearly visible is the central bar with its bright central bulge as well as multiple dark dust lanes and areas of nebulosity in the sweeping arms. At a distance of 15 Million light years, the Southern Pinwheel Galaxy, whilst close in astronomical terms, is too far away and hence way too small for my backyard telescope to resolve individual stars; so all of the stars that can be seen are in fact in the near foreground of the image and reside, like us, in the Milkyway Galaxy. Much harder to see are the many far more distant galaxies that look like tiny fuzzy stars in the image. The easiest of which are PGC 724536 and PGC 48132 that appear close together in the centre of the image just to the right of Messier 83. Both are edge on and look like tiny flying saucers. Details: Skywatcher Quattro 10" f4 Newtonian. Skywatcher AZ Eq6 GT Mount Orion 80mm f5 guide scope and auto guider - PHD2 software. Nikon D5300 (unmodified) Hutech IDAS D1 filter, 14bit NEF, Long Exp. NR on. 25 June 2016. 17 x 4min ISO400 Pixinsight and photoshop. Links: https://500px.com/mikeoday http://photo.net/photos/MikeODay
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Update: 3rd June Re-processed to remove slight magenta tint caused by the non-uniform removal of light pollution by the DBE process ( it was being fooled by the very bright image centre ). The globular star cluster Omega Centauri ( NGC 5139 ) in Centaurus ( please click / tap on image to see larger and sharper ) A full size image can be found here. original below ..... A newly captured ( May 2018 ) image of the great southern globular star cluster, Omega Centauri ( NGC 5139 ) Omega Centauri ( NGC 5139 ) in Centaurus - ( please click / tap image to see larger and sharper ) A full size ( ~ 6000 x 4000 ) image can be found here ....... This image is an attempt to look deeply into the mighty Omega Centauri star cluster and, by using HDR techniques, record as many of its faint members as possible whilst capturing and bringing out the colours of the stars, including in the core. Image details: Resolution ........ 0.586 arcsec/px ( full size image ) Rotation .......... 0.00 deg ( up is North ) Focal ............. 1375.99 mm Pixel size ........ 3.91 um Field of view ..... 58' 20.9" x 38' 55.1" Image center ...... RA: 13 26 45.065 Dec: -47 28 27.26 Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture : 1470mm f4.7 Mount: Skywatcher Eq8 Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.9um pixels)\ Location: Blue Mountains, Australia Moderate light pollution ( pale green zone on darksitefinder.com map ) Capture ( May 2018 ) 8 sets of sub-images with exposure duration for each set doubling ( 2s to 240s ) all at ISO 250. Processing: Calibration: master bias, master flat and master dark Integration in 8 sets HDR combination Pixinsight May 2018
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The Southern Pinwheel Galaxy ( Messier 83, NGC 5236 ) in the constellation Hydra. Additional sub-images added ( 9 x 3 min @ ISO 200, no filter ) and colour balance tweaked to remove slight yellow/green tinge. The lower ISO and removal of the LP pollution filter has made it easier to bring out the subtle colours in the stars. ( click on image to see fuill size ) Messier 83 is a relatively large and bright spiral galaxy visible from southern and mid latitudes. Clearly visible is the central bar with its bright central bulge as well as multiple dark dust lanes and areas of nebulosity in the sweeping arms. At a distance of 15 Million light years, the Southern Pinwheel Galaxy, whilst close in astronomical terms, is too far away and hence way too small for my backyard telescope to resolve individual stars; so all of the stars that can be seen are in fact in the near foreground of the image and reside, like us, in the Milkyway Galaxy. Much harder to see are the many far more distant galaxies that look like tiny fuzzy stars in the image. The easiest of which are PGC 724536 and PGC 48132 that appear close together in the centre of the image just to the right of Messier 83. Both are edge on and look like tiny flying saucers. Details: Skywatcher Quattro 10" f4 Newtonian. Skywatcher AZ Eq6 GT Mount Orion 80mm f5 guide scope and auto guider - PHD2 software. Nikon D5300 (unmodified) 14bit NEF, Long Exp. NR on. 25 June 2016 - Hutech IDAS D1 filter, 17 x 4 min @ ISO 400 28 June 2016 - no filter, 9 x 3 min @ ISO 200 Pixinsight and photoshop. Links: https://500px.com/mikeoday http://photo.net/photos/MikeODay Edited June 27 by mike005
