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Sharpless Sh2-170

Tom How

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Not far from my previous CTB1 target is Sh2-170 from the Sharpless catalogue. This is about 20 arc minutes across, so a bit of a squeeze on my setup. 

Full sized image available on this page:

Didn't clear last night until gone 11pm but I was about to get 12x1200s frames with the Astrodon 3nm Ha, Skywatcher 200 and the homemade telescope mount.

Not very good star shapes - but I had the mirror off yesterday for the annual clean, so anything could be out of alignment. I'll fiddle with that when we get one of those full moon clear nights!


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    • By gorann
      I have done it again although I know I should really have gone to bed since I had to work next day, and it is obviously better to image small faint nebulae on dark nights. Nevertheless, I had a go at this one on Sunday night with my double Esprit rig. I even had to fight with clouds so I only managed to catch 30 x 5 min of RGB with the Esprit 150 and ASI071 and 9 x 15 min of Ha with the Esprit 100 and ASI1600MM (Baader 3.5 nm filter). I actually went to bed around midnight when there were plenty of clouds around and I only had a handfull of subs, but I left the rig shooting away  and apparently it cleared for a couple of hours.
      To my surprise, and after much processing, it became a relatively presentable image. I had no gradient problems as I was pointing away from the moon but the sky was too bright too allow me to tease out the faintest structures in the dusty background. Yes I know, @vlaiv may tell me that this is how it is all the time to image from urban areas and I am spoiled having my obsy on the dark country side.
      The Small Rosette Nebula or SH2-170 is the dot in the Question Mark Nebula and not that much imaged on its own. I really should get back to it on a dark night.

    • By alanjgreen
      Having just published my "Best of Sharpless" object list...
      Here is a full list of the 313 Sharpless objects together with their location information (based on nearest star from Sky Safari) and with a GOTO reference for your mounts (I was using a SynScan handset).
      For those astronomers out there with a Ha narrowband filter and an urge to get images of "something new" or "something different" then here is something to get your teeth into!
      I have just spent the last 16 months exploring 303 of 313 Sharpless objects and I had a great time, there are some very rarely observed objects in this list  
      What follows is a data table of all 313 Sharpless objects. For each object the table shows:
      Sharpless Reference, Observed? (1=YES), Best Of? (1=YES), Physical Size, Scope Used (B=Borg107FL, D=20” Dob), SS Star Ref (An object that I located manually at this star position), Goto ref (Closest SAO, NGC, M object for Goto mounts), Catalog Name (The more famous objects already have a name) In SS? (1= object in Sky Safari, 0=No) Note (details Sky Safari/Bracken errors)

      Here is the raw excel file:
      sharpless targets v8.xlsx
      Hope this helps you find and observe one or more of these wonderful nebula   
      Clear Skies,
    • By alanjgreen
      I purchased a Night Vision Monocular in April 2018 to attach to my TeleVue eyepieces and use for astronomy purposes.
      Initially I purchased an Astronomik 6nm Ha filter (I later switched to a Chroma 5nm Ha filter) to allow me improved views of many visible nebula but I discovered that I now had access to a whole new world of previously invisible (to me) nebula.
      I discovered that many of these were in the “Sharpless” catalog and began a journey to see how many of the 313 catalog objects that I could find/observe.
      I wrote an article in the Webb “Deep Sky Observer” (Issue 181) detailing my joy and initial efforts to observe the Sharpless objects using my Night Vision Monocular.
      Last week, I observed my 303rd Sharpless object. Of the ten outstanding, one does not exist (sh2-214) and nine and very low on my Southern summer horizon (and will be left for a Greek holiday sometime in the future!) so I am ready to publish my findings in the hope that they may assist others who take the same route in the future.
      Finding the Sharpless Objects
      Before you can observe an object, you need to find it and get it into the eyepiece (obvious)…
      My main scope is a 20” push-to Dobsonian which I attach to Sky Safari 5 Pro and push to my chosen targets.
      I soon discovered that the Sky Safari database only contains 249 entries and a small number of these are in fact erroneous or duplicates. In all, I have had to locate 75 Sharpless objects manually…
      I would like to call out the book “The Astrophotography Sky Atlas” by Charles Bracken at this point, as my search would have soon been abandoned if it had not been for this book and its great tables of Sharpless object data (at the back). With this data and the galaxymap online explorer, I was able to use sky co-ordinates to find nearby stars (in Sky Safari) and then hunt around that area to finally find and record an accurate positional star.
      Many Sharpless objects are huge and so I also employed a second widefield scope, a Borg 107FL, which I paired with a Skywatcher AZGTi GOTO mount with SynScan handset. As I found the Sharpless objects, I recorded the nearest SAO catalog star and then used this for the GOTO mount to get the Borg107FL on target. Unfortunately, I discovered that the SynScan handset does not hold the full SAO catalog, so once again there was some “on the fly” rework needed to get the nearest SAO that was in the handset identified and recorded!
      The Best of the Sharpless catalog
      Many of the Sharpless objects were underwhelming at the eyepiece (when compared to objects like the Rosette, Gamma Cygni or the Orion nebula) but when you consider how faint and small some of these objects are then there is more to this than just the “visual beauty” perceived at the eyepiece.
      However, there is no denying that many Sharpless objects are very beautiful at the eyepiece and in many cases are equal or even better that the better known and more photographed Messier nebula objects.
      I am therefore publishing my “Best Of Sharpless” list, it is entirely based on my own perceptions so feel free to disagree with the objects that I have selected, I will not be offended.
      My goal is to inspire just one person (who has an Ha filter) to turn their scope to one or more of these objects and for them to observe an object that they have never seen before!
      What follows is a data table of 115 Sharpless objects (the best of according to me). For each object the table shows:
      Sharpless Reference, Physical Size, Scope Used (B=Borg 107FL, D=20” Dob), SS Star Ref (An object that I located manually at this star position), Goto ref (Closest SAO, NGC, M object for Goto mounts), Catalog Name (The more famous objects already have a name)

      Here is the raw excel file,
      Best Of Sharpless v1.xlsx
      If you have an Ha filter then I encourage you to give them a try!
    • By alanjgreen
      Date: Thursday 13th December 2018. 1940-2230hrs.
      Scope: Borg 107FL f5.6 (focal length 600mm).
      Night Vision: PVS-14 with Photonis 4g INTENS.
      Eyepieces: Plossl 55mm (f2.6 x11).
      Filters: Astronomik 6nm Ha CCD.
      Moon: 33%
      After a run of sessions with the big dob, it was time to get the Borg107 out and try to confirm some of my Sharpless object finds with the smaller aperture scope.
      I have created a spreadsheet of the Sharpless catalog objects with the sizes and Sky Safari locations together with a SAO star reference of a nearby bright star (these need to be confirmed as available in the Skywatcher SynScan handset too as not all SAO numbers are present).
      I missed going out on Wednesday night having just had a wisdom tooth removed and therefore not wanting to get out in the cold. But tonight I was going out whatever…
      Lets get ready to rumble.
      At 1900hrs the sky was not too promising, there were visible stars to the East and North, but the West was clouded out and the south disappearing from the West. The wind seemed to be from the West so I was expecting the clouds to come over.
      However, having spent the afternoon on preparation and with a printout to hand, I decided to get out and make a start as there are many Sharpless that the Borg has not yet attempted!
      I setup the scope & mount indoors, attaching the dew strips and handset etc, then carried it outside in one go (its so light). I then had my eyepiece case (pre-loaded with what I needed) and my books and Ipad (in waterproof case) to set out on the patio table.
      Setting up, the 2-star alignment worked first time and my test of M34 put it just off centre in the Ethos 6mm.
      I setup for night vision by adding the Astronomik 6nm Ha CCD filter to the diagonal and changing to the 55mm TeleVue Plossl & attached the PVS-14 with the TNVC afocal adapter.
      Onto the Sharpless target list...
      I started overhead at the zenith and then moved through my target list down towards the East/South East (where the sky was clearest). I attempted to enter the SAO number from my print-out into the SynScan handset (if it was present then great, otherwise if not then I needed to refer to Sky Safari and select another bright star close to the target and try that in the handset …). There were five targets where the chosen SAO was not in the handset but I was able to find a replacement without too much time lost, each time updating the print-out so I can fix up my spreadsheet today...
      Sharpless targets seen by the Borg107 for the first time:
      Sh2-204 – circular patch under 4 stars.
      Sh2-205 – Huge “heart” shaped structure with a brighter curved edge. A small bright blob was seen half way down one side. Pretty faint but the edges can be traced.
      Sh2-218 – A new one for me. Very large triangular shaped patch. Black shapes seen inside. One corner seems to extend out in a “open wings” shape.
      Sh2-220 – California nebula appeared bright and fitted nicely in the fov. It was brighter along the outer edges and I could see the brightest central edge and the black eye opposite.
      Sh2-221 – A large structure with traceable edges. It was narrow at one end, then expanded out to a wider opposite edge. There were lanes passing across at the larger edge that seemed to split the whole shape into two sections. Images this morning are similar but not exact, I will need to revisit this target.
      Sh2-222 - A small bright blob around a star. Seemed to extend out more to one side.
      Sh2-223 – Seems to be huge. Several curved edges seen. Seems to go up more than across. I see a square looking corner. Hard as there seems to be plenty of nebulosity around in this area.
      Sh2-224 – Again, lots of nebulosity in this area. I see a small bright straight up section (going past a bright star).
      Sh2-225 – Faint patch with a black area inside (I see stars making “3 corners of a square” shape).
      Sh2-228 – small bright patch near to a star.
      Sh2-227 – faint patch. Smallish size. Star pattern at the top looks like a “sword handle”.
      Sh2-232 – Decent sized faint patch. Smaller brighter patch to the side.
      Sh2-240 – Fills the FOV. Plenty of faint nebulosity. Black patch with some double stars within. Several black lanes running through.
      Sh2-242 – small bright patch.
      Sh2-241 – smallish faint patch above a star.
      Sh2-243 – faint smallish patch with black central area with 2 stars.
      Sh2-246 – A large patch, fills fov. 7 bright stars in staggered line running through inside a black lane.
      Sh2-250 – A cloud of faint nebula surrounds 2 bright stars.
      Sh2-268 – A decent sized patch. Black central shape with a star inside. A bit like a “poor man’s Rosette”.
      Including some revisits of old favourites...
      Sh2-252 – Monkeys Head looking great. Its upside down and if you turn the gain right up then it takes on the appearance of a side-on “Minnie Mouse”!
      Sh2-248 – IC443 SN remnant. Nice bright curve seen, behind it are very faint tenticles of the Jelly Fish.
      Sh2-249 – IC444 sits to the right of IC443. It’s a large black shape inside a spreading nebula patch. A bit like “the flame” nebula.
      Sh2-254 – sh2-258 – I see three members of this group tonight. A large patch to the left and two similar smaller patches to the right.
      IC410 - Bright patch with multiple dark areas within.
      IC417 - Less bright patch with some additonal clusters and patches around the fov.
      Flaming Star - A lovely quotation mark shape fills the FOV. I can just make out some of the brighter wisps within.
      All good things come to an end.
      By now, I was getting a little cold in my fingers and the AZ GTi had developed an unwillingness to slew into Orion. The clouds from the West had made their way mostly over the top by now too.
      As a final hurrah, I manually slewed to the Flame and Horsehead (using the red dot finder) for a quick look - they both appear in the same fov, the horsehead is more than a notch but you cant hold the full head shape in direct vision at x11 magnification - then manually slewed up to the Rosette to see if I could see the “Head of a puppy” once again. The Rosette was not as bright as last time out but the “Puppy Head” shape was there!
      The AZ GTi refused to slew into the Orion region at all! I tried choosing various NGC, IC, SAO numbers from within Orion, the handset would show “slewing” but the mount just did not move. If I chose any previously visited SAO or NGC then the mount happily made its way to that target but Orion was out of bounds! I have updated my mount software this morning and ordered a lead to update the handset software to hopefully rectify this strange issue.
      Other than that, it was a pretty decent night. GOTO certainly makes the job of finding those targets much simpler and allows maximum time at the eyepiece.
      As always, it helps to have a plan prepared and a nice list of SAO numbers to slew to is a real bonus.
      Clear Skies,
    • By alanjgreen
      Date: Monday 3rd December 2018. 1950-0100am.
      Scope: 20” f3.6 Lukehurst Dob with Paracorr (fl = 2089mm & f4.1).
      Night Vision: PVS-14 with Photonis 4g INTENS.
      Eyepieces: Plossl 55mm (f2 x38).
      Filters: Astronomik 6nm Ha CCD.
      It was rainy on Sunday so I set about building a “target list” of the Sharpless objects that I have so far failed to observe either because they are not in Sky Safari or they were too faint to see.
      I built-up a table of 25 targets and spent time marking stars in Sky Safari that almost matched the co-ordinates shown in the back of the Bracken Astrophotography Sky Atlas. I also tried to lookup photographs of “groups of Sharpless” objects on the internet so that I could try to take bearings from “known” Sharpless to point me to potential locations of the missing Sharpless!
      After 4 hours my table of targets was ready…
      Time to “boldy go where no-one has gone before”…
      Monday 3rd December was forecast as potentially clear all night. So after eating my evening meal I set off down to the scope-shed with my night vision case.
      I quickly setup the big dob and had the two-star align (of my Nexus) completed. Then headed for the first target on my list…
      Sh2-164 – Found near star TYC 4021-1255-1. A small bright patch sitting next to a star.
      Sh2-169 – Found near star SAO 020964. Very faint object, can be seen at the edge of the fov if you centre sh2-168. Stars make “3 corners of a square” inside the faint patch.
      Sh2-176 – Found near star HD 2559. Very faint indeed. A bright cluster (M34/Xmas tree like) has nebulosity around it and a black area inside it too.
      Sh2-177 – Found near star HD 2654. You see a large star cluster (that reminds me of “a Rocket on a stand”). The cluster has a lane of nebula running along the side of it.
      Sh2-179 – Found as pneb BV 5-2. Tiny planetary neb bright enough to be easily seen.
      Sh2-180 – Found near star TYC 4020-0924-1. Bright, decent sized cluster “crab,lobster” shaped with nebulosity surrounding and several black lanes within. The “crab” stars may be part of a larger “butterfly” shaped formation.
      Sh2-181 – Found near star TYC 4024-0109-1. Small bright patch sitting above two bright stars. Averted reveals a rounded black shape curved nebula over the top.
      Sh2-183 – Found near star TYC 4029-1063-1. Seems to be a long lane of nebulosity running up from near sh2-181.
      Sh2-191 Found as galaxy Maffei1. Small patch on top of two stars.
      Sh2-215 – Found at star HD 276169. Small faint patch sitting above a star.
      Sh2-250 – Found near NGC 1633. Several stars sit in a clear black lane. Very faint nebula around the black lane!
      Sh2-251 – Correctly marked in Sky Safari . Several spaced out bright stars up against a wall of nebula. Wall is thick and curves slightly at the lower end.
      Sh2-253 Found near star TYC 1336-0819-1. Very faint patch seen in a “gap” found in a line of stars. There are 6 or 7 stars in a row, then the “gap”, then a final star.
      Sh2-272 – Found at star GSC 0738-2191. This is a very tiny patch sitting just at the side of sh2-271. I missed it before (helps if you have seen an image beforehand!)
      Thoughts of the observer.
      I managed to find 14 of my 25 targets so I am very pleased with that.
      I also uncovered an error in the Bracken Astrophotography Sky Atlas where the co-ordinates for sh2-213 are incorrect, (they are duplicates of sh2-212) that’s why I have not found it so far. I got some “new” co-ordinates off the internet this morning so I am ready to try again for this one!
      My failures were sh2-172, sh2-195, sh2-213, sh2-266, sh2-270.
      Around 1am the sky just filled up with water and the heaven’s disappeared, this stopped me in my tracks and left a few lower Orion targets not attempted.
      It was a cold night (I was running eyepiece & secondary mirror heating all night) and the UTA of the scope was frozen in ice by the end of the session.
      My Sharpless count now comes to 201 of 313 objects.
      I have created a spreadsheet of the catalog and added all my location information. I am also adding GOTO references to each of the rows (which I am testing on the Borg107 as time allows). Let me know if you want a copy?
      Clear Skies,
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