NEO and Comet research at Sandlot

The following is a list of comets recently recovered at Sandlot ;                             For a list of all 6,200  NEO and NEOCP follow-up
                                                                                                                          Observations from Sandlot .
   click here for more information
COMET P/2008 X2 (LINEAR)  (password accessed only I.A.U.C. <> no - link )
MPEC 2009-C19 : COMET P/2002 O8 = 2009 B5 (NEAT)
MPEC 2009-C03 : COMET P/2005 R2 = 2009 B3 (VAN NESS)

MPEC 2009-C04 : COMET P/2002 CW134 = 2009 B4 (LINEAR)
MPEC 2009-Y17 : COMET P/2003 CP7 = 2009 X1(LINEAR-NEAT)
MPEC 2010-Q05 : P/1998 U4 (Spahr) = P/2010 P3

There is a Brome pasture
surrounding the observatory providing a relatively stable air  flow .

The city of Topeka ( Pop. 120,000) is only about 12 miles to the north

and there are the much smaller towns of Scranton and Carbondale
 just a few miles away in opposite directions. This does keep the
Observatory in the green zone of the light pollution world map. 
Still, I can image to magnitude21.6 R (unfiltered) with a composite of
30 to 40 minute images on an exceptional night.


I recently turned in observations of a comet at

magnitude 20.6 V.  while the 93% sunlight moon was high in the sky. 



I regularly perform astrometric follow-up observations on objects listed on the NEOCP , the NEODYS Priority Page (Italy) , and the 'NEO's not seen in a while' list maintained by the Minor Planet Center.  I've turned in 2,200 observations from Sandlot (and thousands more from observing at Farpoint  25 miles from here).  I've also discovered several hundred  main-belt asteroids, co-discovered a comet (178P) , an Amour-type NEO (1999 RO36) , and 5 Trojan asteroids ( those with orbits at roughly the same distance as Jupiter but 60 degrees on either side of the Jovian planet.) . I've also recovered 5 comets during the last 2 years at Sandlot (see above links).     My efforts at Farpoint has abated while others there use the Tombaugh reflector for some asteroid follow-up and other photometric pursuits. I now spend most of my observing time (20 -30 hours per weeks)  at Sandlot  ( ~ 30 meters from my house ).  A great advantage in Sandlot is no drive time. Plus if there is just a couple of hours for observing because of schedule or weather I can be productive in 10 minutes vs. non-productive for those 2 hours of travel time.

 I use an STL 1001-E camera with its 1056 X1056 X 24 micron pixel array (provided by a Shoemaker NEO Grant in 2009 by the Planetary Society)  . That  camera boosted my F.O.V. to ~ 32 arc-minutes ( larger than the full moon in sky coverage).  I especially like to hunt down objects that are not likely to be serendipitously found by the surveys either because they are too faint or too far off the ecliptic or both.   Though starting out a 2 month long rainy period  and one lightening strike (that knocked out $600.00 worth of equipment ) slowed the camera's start-up.  Sandlot is now back to locating more semi-lost NEO's and comets.  

    The 'Little Blue 22'  ( LB22 ) fork mounted Newtonian reflector is a home built  heavy telescope.  I used 1 & 1/2 x 0.65" wall  square steel tubing for the OTA.  My welding skills improved a bit as this project was being done but some of my earlier welds weren't very pretty.  They were, however,structurally solid. I used a 3/8" thick steel plate ( probably overkill here) and had it CNC  flame cut with a pattern to mate with the forks and supply a 24" radius disk where I ran a pinch roller design R.A. drive. I've also designed a pinch roller declination using the square tubing as struts and rolled a piece of 1/4" x 1 1/2" wide flat steel in ~ a 36" radius  I then rolled and floated another piece of 1/4" x 2" stainless steel flat on top using 1/4-20 bolts and a series of stiff  springs  to space it above the plain steel rolled flat. That lets the stationary pinch roller make slight adjustments to the position and angle of the flat SS,  if it does not line up perfectly.  Because the pinch roller is stationary the distance from the axis doesn't change and the declination and RA track  fairly smoothly. There is usually only a couple of thousandths of an inch variation at most in the thickness of plain steel disk, making it usable in a pinch roller system. The RA drive uses a 1" diameter 304 Stainless steel shaft that has been tapered to match exactly the driver shaft  to disk contact surface. (about 3/4 degree per side amounting to ~ 0.040 "  diameter smaller on the top of the shaft than the bottom of the shaft that is in contact.) The shaft is angled slightly to match.

The SiTech system does a great job with tracking and although I still can't reliably track for more than 1 minute without guiding at this point it is very well behaved with a guider. It's pointing accurate enough to put most objects on the field of the CCD requiring just a bit of button pushing to center the object.  Hats off to Dan Gray and SiTech for making such a versatile and accurate drive system.  Total cost of my drive was ~ $1,000.00.  Pretty darned inexpensive for such a big scope ( weighing approx. 1,500lbs total). 

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