http://www.clearskyinstitute.com/xephem/ http://www.phy.ohiou.edu/~tss/ASTR410/findingcharts.html (this is RE: older version xephem) following for xephem V 3.7.3 Aim: prepare observing charts (finder images and star location info) Aim: Make a Data Table that reports the airmass of standard stars start xephem in a terminal tkirkman@linphys1 1% xephem set observation location: under Local Chicago, Illinois-> SJU Observatory Set set observation time: click on calendar day (NM=new moon) set Local Time to be say, 9pm=21:00:00 click: Update write down UTC Time & Sidereal Note: almost always you can find your cluster in NGC.edb or Messier.edb Many standard stars are in UBVRI.edb, Landolt83.edb or Buil92.edb, however not uncommonly you will have to add location data into xephem's Favorites database; this process is described near the end of this file. For this project I assume M39 is the target, with standard regions IC4665 and NGC6940, for a fall date. To initialize the telescope we need the star number of an obvious, bright star. Aim: make a star map that reports star# for bright obvious stars (to aim telescope for initialization) The bright obvious stars known to the telescope are in the file Meade250.edb Data->Files... Delete, in the list of Loaded Catalogs, everything except NGC,edb, Messier.edb and Meade250.edb To add Meade250.edb to the list, in the Database Files window: Files->and select Meade250.edb View->Sky View (circle mapping dome-of-sky appears) in Sky View menu: Control->Print... click on Print command, and then OK hardcopy should appear on the default printer. Aim: make a data table showing basic info for target areas. Data->Index... In the Search: box enter: M39 (case counts!) information on the open cluster M39 should appear, click: Save as Favorite In the Search: box enter: IC4665 (case counts!) information on the open cluster IC4665 should appear, click: Save as Favorite In the Search: box enter: *6940 (wild cards work!) information on the open cluster NGC6940 should appear, after a few searches click: Save as Favorite in the main window: Data->Favorites deselect the button in front of Use Sun,P continue and deselect: all the planets (but leave selected Moon, M39, IC4665, and NGC6940) in main window: View-> Data Table Control->Setup de-select: Az, Vmag, Elong, TrnAlt select: Air click: Apply The result should be a data table with RA, Dec, Altitude, AirMass, RiseTime, TransitTime, SetTime Control->List allows you to save this data in the file .xephem/datatbl.txt You can make hardcopy with: bethe 46% lp .xephem/datatbl.txt Aim: Find a bright star (~4mag) near M39 for finding/focus Stars brighter than 7mag are in SAO_LX200.edb in the Database Files window: Files->SAO_LX200.edb to load these locations In the Sky View see that *232 (Deneb, aka SAO49941) is close to M39, but probably too bright Using the lhs vertical scroll bar reduce the Field-of-view (FOV) To bring M39 into the center of this magnified view Favorites->M39 see the star 50424, which a search in Index shows is 3.72mag with extreme zoom on M39 see 3 SAO stars inside M39: 51001, 51024, 50984 the telescope could use those SAO# or M39 to goto this object Similarly find the 2.77mag star *203 near IC4665 and *233 2.46mag near NGC6940 According to http://www.noao.edu/wiyn/obsprog/images/tableA.html http://www2.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/community/STETSON/standards/ the standard region L110 provides a nearby set of standard stars, however it is not in any existing database. Stetson says the location is: 18 42 20.6 +00 12 17 with brightest star L110-353 @8.450mag I learn via web to simbad that this star is: V* HK Aql = SAO 123824 = HD 172829 But I'm more interested in the region around L110-499 which Stetson says is at 18 43 07.68, +00 28 01.8 simbad ids that location as: TYC 447-246-1 a 11.75mag (Stetson says 11.731) star In the Add edb: box of the Favorites window I can enter the data for this star The enter line must be exactly as follows: format: object_name,f,RA.as:H:M:S,DEC.as:D:M:S,1 L110-499,f,18:43:07.68,+00:28:01.8,11.7,2000,0 Notes: commas are required "f" means fixed trailing 1 is a meaningless magnitude I'd copy&paste the RA & dec data to avoid typos Hit the Save to: button to record this data Consider cluster Upgren 1 (which is not in NGC.edb file) Add to Favorites with Upgren 1,f,12:35:00,+36:18:00,1 *133 (2.9mag aka SAO63257, with SAO63256 its 5.6mag companion) makes a nice focus star SAO63118 is the nearest SAO_LX200.edb star Stars will be *labeled* with magnitude if Control->Options Labeling: for Stars...click M (rhs box) You can control the limiting magnitude in Control->Filter menu From UBVRI.edb you might select standard stars: 107 484 (11.3mag) 106 700 (9.8mag) Meade has established shortcuts to 250 very bright stars (mag<3.5). These stars are a good first place to setup crude focus and RA/dec. Typically they are so bright that the CCD saturates (but they are easy to find in the finder scope). They can be found in the database: Meade250.edb exit xephem: File->Quit Standard Stars... You can locate standard stars by Data->Files->Files UBVRI.edb or brighter standards in Landolt83.edb or Buil91.edb You can limit the Sky View display to bright stars via: Control->Filter find slider: Stars Lim Mag Many of these stars are the canonical equatorial standards published by Landolt: Landolt, A.U., AJ, 104, 340 (1992) A nice feature is to capture several standards in one frame. WIYN (see below) has a nice list of such recommended fields 92 250 00:54:37 +00:38:56 13.178 95 330 03:54:31 +00:29:05 12.174 98 653 06:52:05 -00:18:19 9.539 RU 149D 07:24:16 -00:32:38 11.480 RU 152D 07:30:03 -02:04:16 11.076 PG0918+029D 09:21:22 +02:47:30 12.272 101 327 09:56:09 -00:25:50 13.441 101 421 09:57:16 -00:17:16 13.180 PG1047+003C 10:50:18 -00:00:23 12.453 104 334 12:42:21 -00:40:28 13.484 PG1323-086D 13:26:05 -08:50:34 12.080 labeled -085 at WIYN 107 602 15:39:19 -00:15:29 12.116 107 484 15:40:17 -00:21:13 11.311 PG1633+099B 16:35:34 +09:46:22 110 232 18:40:52 +00:01:58 12.516 110 266 18:42:49 +00:05:06 12.018 110 506 18:43:19 +00:30:27 11.312 111 1969 19:37:44 +00:25:48 10.382 MARK A 20:43:59 -10:47:42 13.258 113 342 21:41:00 +00:27:34 10.878 PG2213-006B 22:16:22 -00:21:49 12.706 My Target: Upgren 1 (Note: this is a bit unusual: most targets will have M# or NGC# and can be found directly) Standard Stars: 106 700, 107 484 (Find in the database: UBVRI.edb) from: http://www.noao.edu/wiyn/obsprog/images/tableB.html http://www.noao.edu/wiyn/obsprog/images/tableA.html http://www.noao.edu/wiyn/obsprog/images/atlasinfo.html (Note: images here are 7'x7'...smaller than out camera) FYI: xephem is not to be trusted on cluster information If I hit the Camera button (top-left) on any of these objects I get a DSS image of the region Note that the "nose" or Gaussian peak just above Where on the rhs allows you to measure magnitudes. If you do this I'd also turn on the Magnifying Glass and Plot center Row & Column to see the pixels for skymap...alternative: Fire up web browser: http://www.fourmilab.to/yoursky/ select nearby city: Minneapolis edit resulting data: Universal time: as recorded in xephem for 9pm Latitude & Longitude for SJU Observatory (see .xephem/datatbl.txt file) de-select Constellation Boundaries de-select: star Names & Bayer/Flamsteed codes Image size: 1000 Colour: Black on white background print result your own FIT files: wcs RA/dec coordinates View->Sky View->Images->Load and Save (view image & FITS header) Control->Field Stars (select Hipparcos) Images->WCS solver S/N ration (increase, e.g., to 50) & Mark Stars enter data (e.g., for IC 4665) 17 47 08 5 13 31 .00046 .00046 Go now have RA/dec in image; can save FIT with WCS but gaia cannot read; Aladin can same area gives gaussian fits to PSF; basic stats on regions, etc BD+05 3495 17 47 08.6 +05 13 31