images and Studies
from Starlight Farm Observatory
About the Observatory
|Location||Barnesville, MD, about 35 miles NW of Washington DC, USA|
|Telescope||C-11 optical tube f/10 or 6 inch f/12 AP "Super Planetary" Refractor (with two internal flats to provide short tube length). Scope fitted with RoboFocus for remote control focus, video viewfinder, etc. Includes Celestron f6.3 reducer, Optec x3 reducer, x1.8 Barlow, x3 Barlow.|
|Mounting||AP1200 Mount on Steel pier attached to pad (no footing)|
|Imaging Camera||SBIG ST7E with photometric filters|
|Software||Generally use TheSky® for scope control, MaximDL for image acquisition and processing, and home-grown software for remote parking/unparking|
||SBIG DSS7 Spectrometer, with usual imager being an SBIG 402
camera. Telescope control using TheSky, as well as home brew
tracking and DSS7 control software. Imaging controlled by Maxim,
analysis using Maxim and Excel.
Ten Foot Pro-Dome, which can be operated by motors in the dome, or controlled remotely with Digital Dome Works from office that is 400 feet away (or longer using telephone link or Internet)
Note: All images are compressed JPEG files, file size under 100k except where noted.
|M82 taken 1/21/2000. f12 4600 seconds, MaxEnt and DDP processed. Shows apparent star/supernova?.|
|M82 taken 1/7/2001 f12 13x10min, MaxEnt and DDP processed. Star/supernova missing.|
|Mare Nectaris area. This shows the many small craters in the area. See if you can spot the DHCs mentioned below.|
|Dark Haloed Lunar Craters (DHC). The moon has several dozen small craters that are surrounded by darker material. Not much is known about the cause of the dark material; however, volcanic emission seems to be one of the leading theories. After stumbling onto a pair of these in Mare Nectaris, I have been studying the contrast under different lighting conditions to gain some additional insight. The relatively poor seeing in our mid-Atlantic area, and the small refractor, make this study at the edge of feasibility. Here is a picture of the area, somewhat enhanced. Theopholis (75 km dia) is the large crater at the bottom of the picture. The upper DHC is about 3 miles in diameter, the lower one is about half that, and not easy to see under this lighting.|
|M57. Stimulated by the excellent picture on the right by a well known astrophotographer, I took the picture on the left with my 6 inch. Clearly the right hand picture is better, but the left hand shows that with effort you can still do good work with a small scope. Exposure was about 2 hours.|
|M31, The Great Galaxy in Andromeda. This is a group of three exposures with 20 min. exposures at f4. The mosaic was put together using MaximDL (first attempt). With heavier processing, one can bring out more of the central region, if desired.|
for image of comet
||Comet 2002 (Ikeya-Zha). UL Comet on June 9, 2000 shows some faint anti-tail to the right. To show the tails more clearly, I averaged 16 comet images each rotated 22.5 deg, then subtracted from the original giving UR image. On Jun 21, in strong moonlight, I took 30x1 min exp, median combined. The comet has about half its former brightness. Background moonlight is about 9x the background of the June 9 image. Even so, with no processing, one sees a much sharper and relatively brighter anti-tail to the west (right, sunward) as we pass through the plane of the sun-comet-earth. In the one minute exposures, the anti-tail is about 10 counts out of about 2000 background, the comet nucleus is about 500 counts above background.|
|Mars, taken August 24, 2003. Black and white image compared to a drawing done a few days earlier. (Please read the text below images for more details.)|
|Images of Mars on August 25, 2003. Color vs. back and white. (See text below images for further description.)|
Note: Unless noted, all
are PDF files, which can be downloaded and viewed with Adobe Acrobat
If you do not have the free Acrobat software, click here to download.
||"A Neophyte's Determination of EY Ceph Curves and Orbital
This paper was presented in May, 2002 to a meeting of the International Amateur-Professional Photoelectric Photometry-Western Wing (IAPPP) in Big Bear, California. It describes intitial measurements of the EY Cephius eclipsing binary system.
||"Are Flats Really Flat?"
(PDF file, 42K).
I discovered a characteristic of the ST7E camera in which internal reflections in the camera can create a 2% gradient in the flat. Use of the flat for calibration can then introduce an error when performing high precision photomertic analysis. We show that a simple mask can prevent this effect.
(PDF file, 20K)
Although the optics of the C11 were excellent, I was experiencing image shift as the scope moved to different positions. I modified the mirror cell of the scope to reduce mirror flop. This paper describes the results.
|"Spectrum of Tempel1"
(PDF file, 40K)
Spectrum taken on July 2, 2005 using DSS7 Spectrometer. Very poor signal to noise, but the comet was faint: an interesting first try. See below for better results.
More on Flats
|"Just How Good are Flats?"
(PDF file, 987K)
This paper reports research done on flats used in CCD Photometry. I measured how well different types of flats could, in fact, correct an image. The work shows how to separate out the effects of camera, optics, and flat source. This PDF is the first half of a paper given at the 2005 meeting of the Society for Astronomical Science, and is copyrighted by SAS. The complete original paper can be retrieved at http://www.socastrosci.org/Files/SAS_Proceedings_2005.pdf
|"StarZap: A Method of Removing
(PDF file, 39K)
StarZap is an automated program that can remove stars that interfere with the measurement of asteroid brightness. The program uses tools available in MaximDL. This PDF (with slight modifications) is the second half of the paper described above. The program and source code (VB6) are open source and available free. Click here to download the installation zip file, which includes an essential "READ ME" file.
(PDF file, 551K)
This paper describes my setup using a C11 and DSS7/402 combination to observe astronomical spectra. I also discuss briefly some of the challenges of the operations, as well as corrections needed to make the spectra useful.
Examples of Spectra, v.3
|"Examples of Spectra".
(PDF file, 1.1M)
This paper gives some of my spectroscopic observations of various objects, including M57, and Comets C073 and Comet Swan.
17P Holmes - Spectra
||Comet 17P Holmes - Spectra and
(PDF file, 1.5M)
Images and spectra of Comet Holmes - through November 29, 2007
Comet 17P Holmes - Coma
|Comet 17P Holmes Coma Study
(PDF file, 800K)
An analysis of the coma density, including models and measurements of transparency during the first eleven days after outburst.
(PDF file, 1.1M)
A new method of performing a drift scan to measure asteroid occultations.
|Flat Errors Are Not the Problelm
(PDF file, 377K)
Demonstrating how some "huge errors" in a flat source can sometimes make no difference. Surpirse!
18-inch, f3.5 Newtonian
|Fast Newtonian Scope for
Photometry and Imaging
(PDF file, 8.6M)
This paper describes construction, testing and operation of an 18-inch f3.5 Newtonian telescope, brought into service in 2007.
Remote Scope Cover
|Remote Operated Scope Cover
(PDF file, 1.3M)
Construction of a remotely operated telescope cover (for the scope described above) and associated electronics.
| Can Global Warming be
Stopped? This Power Point presentation outlines a very
pessimistic (but realistic) view of our future ability to cope with
(PDF file, 1.1M)
A Heretic's View of the 7th Principle
|This is a lay sermon that
analyzes the Unitarian-Universalist 7th Principle (concerning the
interconnected web of existence) from a very different point of view
than is common. The sermon discusses global warming as a major
(PDF file, 140 K)
|This paper analyzes energy
sources that could substitute for fossil fuel. The conclusion is
that only nuclear electricity and conservation can meet the major needs
of the world in the short (40year) time available.
(PDF file, 116 K)
Comparing Video Cameras
|How effective are new, more
sensitive video cameras for occultation measurements? This paper
reports my findings when I compared four cameras in six tests.
Results suggest that the increased sensitivity in some models is more
usesful than in others.
(PDF file, 4.4 M)
|Spectrum of Comet Lulin, taken
February 23, 2009, with comparison to Comet Swan spectrum.
(PDF file, 478 K)