April 2010 - Utah-Astronomy - mailman.xmission.com

Re: [Utah-astronomy] PST Ha Solar Test Image 4-24
by Canopus56 26 Apr '10

26 Apr '10

Another thing about running a double-stack Ha set up is that you end up seeing three or four solar images. The faint secondary and tertiary images are called "reflex" images. You have to adjust the double-stack knob to move all of these reflex images out of the eyepiece field-of-view, leaving only the brightest "primary" image visible - (something the Coronado double-stack product insert did not mention). See page 2 in Lunt double-stack Ha manual http://www.luntsolarsystems.com/a/pdf/Double-stack%20manual.pdf - Clear Skies, Kurt

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Re: [Utah-astronomy] PST Ha Solar Test Image 4-24
by Canopus56 26 Apr '10

26 Apr '10

Chuck wrote: > Kurt, a home-made Barlow is an easy solution to customizing EFL. > You can select a negative achromat to suit your needs; you > might peruse the selection at Surplus Shed. The PST really needs 1:1 teleextender to pull that wierd focal plane out of the eyepiece holder to where a camera can get at it. But it's getting to be a moot point, since the Lunt solar telescopes are the new thing to buy and do not have that design limitation. > Perfect achromatism isn't a concern since you are imaging > at a single wavelength. Good point. I hadn't thought of that. So, what's an ethalon and how does the Lunt incorporate into a refractor design? Clear Skies - Kurt

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Re: [Utah-astronomy] PST Ha Solar Test Image 4-24
by Canopus56 26 Apr '10

26 Apr '10

Joe and Patrick - Thanks for the comments. It turns out the 1.5x Powermate isn't made anymore. Today I did a focus test chaining a 2.5x Powermate and with a nose mounted 0.5 1 1/4" focal reducer on an eyepiece. It seemed to yield about 1.25x to 1.5x but the scope did come to a focus. I didn't have time to do a test image today. Hopefully, that will better match the camera or have a wider in-focus travel length. The test had much lower resolution than the prevailing amateur high-end standard-of-practice using the 60mm Lunt Ha and Ka scopes. http://solardatabase.free.fr/tableau.php . At 2pm there was small prominence rising at the east-east-south limb. - Kurt

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Re: [Utah-astronomy] Finding showcase galaxies in the Leo Spur
by Canopus56 26 Apr '10

26 Apr '10

P.S. - Most of the amateur experience with the Virgo Supercluster is confined to within 65 million light years or around 20 mega parsecs. This is about 3% of galaxies in the observable universe that has been mapped to 2 billion light years in distance-then. (65 million ly / 2 billion ly = 3%) Powell's Atlas of the Universe puts this local supercluster in perspective: Powell's plot of from the 2dF Galaxy Redshift Survey to 2 billion light years http://www.atlasoftheuniverse.com/2dfslice.gif Powell's scale diagram of the observable universe: http://www.atlasoftheuniverse.com/universe.gif in http://www.atlasoftheuniverse.com/universe.html - Kurt

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Finding showcase galaxies in the Leo Spur
by Canopus56 25 Apr '10

25 Apr '10

Showcase galaxies in Leo are associated with two separate clusters: the Leo Spur and Leo Cloud. The Leo Spur is much closer - within 20 Mpc or about 65 million light years. The Leo Cloud is much more distant. Leo Spur and Leo Cloud in 3D Plot 40Mpc - View 1 http://www.slas.us/gallery2/main.php?g2_itemId=3244 Leo Spur and Leo Cloud in 3D Plot 40Mpc Rotated 2 http://www.slas.us/gallery2/main.php?g2_itemId=3317 40 mega parsec 3D plots. One tick = 4 mega parsecs. After Tully (1988). Color coding - Dark Blue Local Group Red Coma - Sculptor Cloud Green - dark Leo Cloud Green - light Leo Spur Purple Triangulum Spur Teal Virgo Cluster and Southern Extension Yellow - dark Fornax Cluster and Eridanus Cloud Yellow - light Dorado Cloud Black Not coded in this view Of the seven showcase galaxies in Leo (plus NGC3628, the eighth object), six are in the closer Leo Spur. Only Caldwell 40 (NGC3627) is in the more distant Leo Cloud. Finder for Leo Spur and Leo Cloud showcase galaxies http://www.slas.us/gallery2/main.php?g2_itemId=3320 Showcase Galaxies in the Leo Spur and Leo Cloud - Leo Spur Caldwell053 NGC3115 M095 NGC3351 M096 NGC3368 M105 NGC3379 - including the Leo Triplet M065 NGC3623 M066 NGC3627 NGC 3628 Leo Cloud Caldwell040 NGC3626 (Not charted here is showcase galaxy Caldwell 53 (NGC3115) - a ninth object in the Leo Spur.) For finding the Leo Triplet during after work weekday practice with binos, start with theta Leo and do a 2 deg south declination slew. Try to find 73 Leo with its small "tail" shown on the chart. This asterism is visible in moderately light polluted skies. In heavy light polluted skies, only 73 Leo will be visible. The Leo Triplet is a 1 degree easterly right ascension slew from 73 Leo. Magnitude 7.3 star SAO99552 is in the middle of triplet. Leo Cloud member Caldwell 40 (NGC3626) is in the triangle formed by the tail of Leo - beta Leo, theta Leo and delta Leo. For weekday practice under light polluted skies, try to locate 86 Leo - a magnitude 5.5 star mid-way on the beta Leo to delta Leo line (SAO99637). Caldwell 40 is a 2.5 deg right-ascension slew from 86 Leo. Caldwell 40 is at the intersection of this right-ascension slew line and a pointer formed by 81 Leo (SAO99601, v5.6), SAO99585 (v7.2) and SAO99577 (v7.0). For computer control slewing, Chort (theta Leo, 70 Leo, SAO99512) and Zosma (delta Leo, 68 Leo, SAO99512) are potential hand-controller syncronization stars with less than 5 degree slews to Caldwell 40. To find M105 (and its nearby NGC3371 and NGC3373), begin with 52 Leo (SAO99282) - magnitude 5.5 star along the Chort (theta Leo) and Regulus (alf Leo) line. A 1.5 deg south celestial declination slew reaches magnitude 7.0 locator star SAO99280. M105 is a short one deg easterly right ascension slew from SAO99280. To find M96 and M95, practice by locating magnitude 5.3 finder star 53 Leo (SAO99305). M95 and M96 are about a 1 deg westerly right acension slew and a 1.5 deg north declination slew from 53 Leo. Also note drawf elliptical galaxy Leo I - shown on the finder chart next to Regulus - that I understand requires exceptionally dark skies to be seen. It is member of the Local Group - along with the Milky Way and Andromeda Galaxies. During the afterwork weekdays, practice finding locater stars and asterism can make it easier to find these supergalactic faint fuzzy galaxies during dark sky weekends. Clear Skies - Kurt P.S. - This ends the spring Relam of the Galaxies Virgo Supercluster tour by showcase galaxies in the Messier and Caldwell catalogues. Overview chart of the Virgo Supercluster galaxy groups Unlabeled http://www.slas.us/gallery2/main.php?g2_itemId=3305 Galaxy group labeled http://www.slas.us/gallery2/main.php?g2_itemId=3280

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Observatory update
by Dale Wilson 25 Apr '10

25 Apr '10

Hello all. Ten hours straight can get a bunch done. I demolished the front of the old building. I put on almost all the siding, added the roll-off support struts and part of the roof. Sorry it's such a mess, but after all that I had to defer until Monday to clean up. Later, Dale http://www.slas.us/gallery2/main.php?g2_itemId=3311

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M-63 - More data
by Patrick Wiggins 25 Apr '10

25 Apr '10

I think I mentioned that Tyler suggested I try longer exposures and to bin 1x1. The earlier version was a total of 1 hour binned 2x2. So last night I thought I'd try for 2 hours binned 1x1. But when the two hours was up things were going so well I just let it run and eventually ended up with 5 hours. http://www.slas.us/gallery2/main.php?g2_itemId=3314 If you go to that link and then click on the image you'll get the full 2 MB version. Despite there having been a lot of Moon nearby and some cirrus clouds early on the end result (thanks to Tyler's processing magic) worked out pretty well. Like the last time the image consists of my luminance data to which Tyler has added color data from a picture he took a while ago. See the picture he took the color from on http://allred-astro.com/gpage2.html (3rd image from the top). Tyler's going to try to get some HA data to add a bit more color but probably not for a while. Clear skies, patrick

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PST Ha Solar Test Image 4-24
by Canopus56 25 Apr '10

25 Apr '10

PST Ha Solar Test Image 4-24 Double-stack http://www.slas.us/gallery2/main.php?g2_itemId=3302 No proms or sunspots were available for imaging. From this test I decided that the 2.5x Powermate I am using to raise the focal plane to the camera is magnifying the image past the 40mm PST's diffraction limit. I decided to retry after ordering and receiving a 1.25x Powermate. The PST setup with counterweighting is: http://www.slas.us/gallery2/main.php?g2_itemId=3292 http://www.slas.us/gallery2/main.php?g2_itemId=3295 http://www.slas.us/gallery2/main.php?g2_itemId=3298 - Kurt

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Virgo Supercluster Guide Post Series
by Canopus56 24 Apr '10

24 Apr '10

Craig wrote under a different thread title: > Thanks very much for these guides, they are excellent. Thanks Craig. The overall idea is tour the spring Realm of the Galaxies with a systems view - as components of the Virgo Supercluster. Overview chart of the Virgo Supercluster galaxy groups Unlabeled http://www.slas.us/gallery2/main.php?g2_itemId=3305 Galaxy group labeled http://www.slas.us/gallery2/main.php?g2_itemId=3280 Only one major component to go in this post series - the Leo Group. This year, if I can get better at nailing these faint fuzzies on demand, next year I'm thinking of doing the tour by galaxy type: E, S0, SB, and I. Too bad the Moon is in the way tonight. Clear Skies - Kurt

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Finding Virgo Cluster Southern Extension members M49, M61 and M104
by Canopus56 24 Apr '10

24 Apr '10

Opposite from Canes Venaciti and to the celestial south of the Virgo Galaxy Cluster are a filament of galaxies called the Virgo Southern Extension. The Southern Extension of the Virgo Cluster has always been ill-defined to me in 3-D: Virgo Cluster and southern extension in 3D http://www.slas.us/gallery2/main.php?g2_itemId=3244 Color Tully galaxy group Dark Blue Local Group Red Coma - Sculptor Cloud Green - dark Leo Cloud Green - light Leo Spur Purple Triangulum Spur Teal Virgo Cluster and Southern Extension Yellow - dark Fornax Cluster and Eridanus Cloud Yellow - light Dorado Cloud Black Not coded in this view - but is easily understood in terms of a 2D plot of its members in the celestial coordinate system: Overview chart of the Virgo Supercluster galaxy groups Unlabeled http://www.slas.us/gallery2/main.php?g2_itemId=3305 Galaxy group labeled http://www.slas.us/gallery2/main.php?g2_itemId=3280 The southern extension of the Virgo Cluster is traced by four showcase galaxies: M49 NGC4472 M61 NGC4303 Caldwell52 NGC4697 M104 NGC4594 Virgo Southern Extension galaxy trace http://www.slas.us/gallery2/main.php?g2_itemId=3283 For these four showcase galaxies in the southern extension, I divide the southern extension into two parts for finding purposes - the "northern half" of the southern extension containing M49 and M61 and the "southern half" of the southern extension containing Caldwell 52 and M104. After work practice from a light polluted urban site can aid in finding locator stars for both sets of targets. To find M49 and M61, use the following finder chart: Finder for M49 and M61 - celestial north end of Virgo Southern Extension http://www.slas.us/gallery2/main.php?g2_itemId=3286 To star or finder hop to M49, I like to start at Vindemiatrix (eps Vir). Under light polluted skies using binos, I can still easily find rho Vir and the triangle asterism anchored by mag 5.2 star 32 Vir (SAO119574). From the triangle asterism, then try to find the faint diamond asterism with north south vertices consisting of 20 Virgo (SAO100146) and SAO119453. See chart. M49 lies in the 1.2 degree space between SAO119453 (v6.0) and SAO119413 (v6.4). All or part of the diamond asterism may be an averted object from a light-polluted site. For M61, the closest star hop locator star is 16 Vir (SAO119341, v5.0). 16 Vir easily can be found with a declination slew from eta Vir (16 Vir). eta Vir also easily found in very light polluted skies bewteen bet Vir and Porrima (gam Vir). eta Vir is the only optical wide double along a bet-to-gam Vir sweep line. Once computer synched to 16 Vir, computer control is the easiest means to slew to M61. M61 is about a 1 deg RA by 2 deg Dec right-angle slew from 16 Vir. The key for light-polluted sky practice with binos is to practice locating 16 Vir. M104 and Caldwell 52 are celestial south of Porrima (gam Vir). Finding them under a weekend dark sky can also benefit from weekday after work locator star hop practice. Finder for M104 and Caldwell 52 - celestial south end of Virgo Southern Extension http://www.slas.us/gallery2/main.php?g2_itemId=3308 For Caldwell 52 (NGC4697), a quick and dirty direct slew method is to due a 5.3° right-ascension slew from theta Virgo. An indirect star hop method to Caldwell 52 (and to M104) is to locate chi Vir (26 Vir) - which is visible with binos under a light-polluted sky. To get to chi Vir (26 Vir), begin at Spica (alf Vir). Walk a series of three medium bright mag 5.0 class stars ending in 26 Vir: Spica -> 49 Vir -> psi Vir (40 Vir) -> ending with chi Vir (26 Vir). Under light polluted skies, this line series of star hops easily is seen with binos. From 26 Vir, Caldwell 52 is best found by computer synching and slewing to NGC 4697. By star hopping, the trick is to find faint SAO138697 about 3 degrees at a PA of 45 degrees from 26 Vir. Caldwell 52 is within one degree of SAO138697. There are a number of routes to M104. From 26 Vir, put 26 Vir at the eastern edge of a 1.25 deg eyepiece TFOV and then do a 3.5 degree declination slew to M104. A southern entry star hop route begins at eta Corvus. Under light polluted skies with binos, a triangular asterism anchored by v5.7 star SAO157350 easily can be found. The celestial northern edge this asterism points to M104 - about 2 degrees away. An intermediate hop from the SAO157350 triangle asterism is Harrington 20 - "The Stargate". This is a group of two optical triangle asterism nestled within one another. The Stargate's brigthest star is v6.7 star SAO15739 - which may or may not be in your handcontroller's database. M104 is a 1 deg by 1 deg right-angle slew from the Stargate. Practicing these star hops for bright locator stars during the week can aid in finding related DSOs from a weekend dark sky site. Clear Skies - Kurt Stargate and Jaws asterims near M104 - photo http://www.astro-pat.com/Latest/M104-Jaws-Stargate-032409.htm

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