Visual polarizing photometer
Astronomy
Measuring instrument
Optical instrument
Photometer
Wood, brass, glass
Wooden box with hinged lid, barlow adapter, brass ring. Box measures 30” x 9” x 9”. The photometer is 24” long.
The visual photometer utilizes the polarizing properties of doubly-refracting crystals to measure stellar magnitudes. It is used on double stars where one of the stars has a known magnitude.
“The polarizing photometer used in these observations was constructed by Alvan Clark & Sons. It is of the form devised by Professor Pickering and described by him in Annals of Harvard College Observatory, Vol.11, page 4, where it is designated as ‘Photometer H’. A Wollaston prism forms two images of each star, and these images are varied in intensity by rotating a Nichol placed between the eye and the eyepiece. . . This instrument is capable of extremely accurate results, bit its use is limited to those stars which are closer than about 100”"
Used by Stebbins to observe double stars in 1904-06 and Delta Cephei in 1907 leading to pioneering work by on measuring brightness using electricity making visual photometry obsolete. After Stebbins left in 1922 with the photoelectric photometer, C.C. Wylie resumed using the visual photometer to study WW Aurigae and Delta Cephei. It was used in the 1950s and early 1960s for instruction after a cleaning by J.W. Fecker in 1954. In 1957 Robert Tull and in 1961 Robert Roeder prepared instructions on the photometer’s use.
Alvan Clark & Sons
Stebbins, J. (1907, July) Photometric observations of Double stars. The University Studies, vol, 2, no. 5. University of Illinois Press.
Stebbins, J. (1908). The light-curve of δ Cephei. Astrophysical Journal, 27, 188-193.
Wylie, C.C. (1925). Note on the eclipsing variable WW Aurigae. Popular Astronomy, 33:600-601.
Report of observatories. (1924). University of Illinois Observatory. Popular Astronomy. 32:98-99.
Astronomy Department, University of Illinois, Urbana, Illinois
1899
Michael Svec
copyrighted by Michael Svec.
image/jpg
English
physical object
University of Illinois Observatory Collection A131
University ID 016670, obs 66
University of Illinois Observatory, Urbana, Illinois
Algol light curve
Astronomy
Photometry
Eclipsing binary star
Joel Stebbins used the selenium cell photometer to study the known variable star Algol. The improved accuracy of the photometer revealed the second minimum and the limb darkening.
Astrophysical Journal
Stebbins, Joel. (1910) The measurement of the light of stars with a selenium photometer, with an application to the variations of Algol. Astrophysical Journal, 32, 185-214.
http://adsabs.harvard.edu/abs/1910ApJ....32..185S
1910
English
document
University of Illinois Observatory, Urbana, Illinois
Selenium cell photometer
Astronomy
Photography
Measuring instrument
Electrical apparatus
Photometry
Figure 1: Selenium cell in ice-pack attached to 12-inch refractor. Page 190.
Astrophysical Journal
Stebbins, Joel. (1910) The measurement of the light of stars with a selenium photometer, with an application to the variations of Algol. 32, 185-214.
http://adsabs.harvard.edu/abs/1910ApJ....32..185S
1910
Image from journal
document
University of Illinois Observatory, Urbana, Illinois
Galvanometer room
Astronomy
Photography
Electrical apparatus
Measuring instrument
Photometry
Figure 2: Galvanometer and accessories for the selenium photometer. Page 191.
Visible in the photograph are the galvanometer, reading telescope, scale, batteries,Wheatstone bridge, and resistance boxes. Was located in the west-central transit room.
Astrophysical Journal
Stebbins, Joel. (1910). The measurement of the light of stars with a selenium photometer, with an application to the variations of Algol. 32, 185-214
http://articles.adsabs.harvard.edu//full/1910ApJ....32..185S/
1910
photograph from journal
English
document
University of Illinois Observatory, Urbana, Illinois
Sextant and artificial horizon
Astronomy
Navigation
Surveying
Measuring instruments
Wood, metal, glass
Metal black frame with wood handle and silver scale. Horizon mirror is broken, includes 4 index filters, 3 horizon filters, 3 brass telescopes, 2 lens caps, wooden handle, 6” radius on scale, maker and model 4323 marked on index arm, vernier read by magnify lens.
Box is 9 5/8” x 9 5/8” x 5 ¼” with hinge top, two latches, lock, marked “obs 14,” with metal handle.
Acquired in exchange for small Fauth chronograph. Saegmuller joined Bausch and Lomb. In 1905, the company included all three names until 1907.
The artificial horizon:
Wood, metal, glass
In the Astronomy department is the box with the cover, marked Fauth & Co. Box is 8 3/8” x 6 ¼” x 5 ¾”, dove tails visible, 2 hook latches, exterior university id tag plus paper label #6 .. Both the tray and bottle are corroded. Wind shield is greenish metal and glass. A
The artificial horizon was used with sextant to determine the altitude of objects when the true horizon was not visible. They most commonly consist of a trough, bottle with mercury, and a wind shield consisting of two panes of glass at right angles to the observer’s line of sight. It was used by viewing the sun or star directly and then again in the reflection of the mercury surface. You would then have two measurements can could divide by two. In the Saegmuller catalog (page 63) it cost $30.
Bausch, Lomb, Saegmuller Company and Fauth Company
Astronomy Department, University of Illinois, Urbana, Illinois
1906
Michael Svec
Copyright Michael Svec
image/jpg
English
physical object
University of Illinois Observatory Collection A119.1
University ID 016654, obs14
University of Illinois Observatory, Urbana, Illinois
Sextant
Astronomy
Navigation
Surveying
Measuring instruments
Wood, metal, glass
Black aluminum frame, wood handle, one telescope, no filters, micrometer wheel on vernier scale, arc is black with white engraved scale from 0 to 140. Marked on index arm “U.S. Navy Bureau of Ships ETS Sextant, Mark 2 Mod 0 28012 1943, type no 3052-1-A”.
Bendix Aviation Co., Eclipse-Pioneer division, Teterboro, New Jersey
Astronomy Department, University of Illinois, Urbana, Illinois
circa 1943
Michael Svec
Copyright MIchael Svec
image/jpg
English
physical object
University of Illinois Observatory, Urbana, Illinois
Hough observing chair
Astronomy
Furniture
Wood, metal
Wooden frame with moveable seat and eight steps on four castors. Measures 45” x 48” x 103” tall. Moving adjustable chair with foot-rest connected to counter weights slides up and down in the middle of the stairs with in a wooden track. Seat held in place by friction. A small table that attaches to the chair is missing. Two drawers added later under the steps. Follows the design of Professor George Hough of Dearborn Observatory as published in the March 1881 Monthly Notices of the Royal Astronomical Society, volume 41 pages 309-312.
Bevis and Company built the ladder for $25 based on design provided by Warner & Swasey.
Bevis & Company, Urbana Illinois
Astronomy Department, University of Illinois, Urbana, Illinois
1896
Michael Svec
Copyright Michael Svec
image/jpg
English
physical object
University of Illinois Observatory, Urbana, Illinois
Rumford Medal
Astronomy
Medal
Gold medallion in 3.5 inches square leather case with green velvet. interior. Metal approximately 3 inches diameter, made of gold. Front contains left facing profile of Lord Rumford. Reads “Born 1753 * Benjamin Count Rumford * Died 1814.” Back reads “Rumford medal for discoveries in light or heat” and “Awarded by the American Academy of Arts and Sciences to Joel Stebbins for his development of the Selenium Photometer and its applications in Astronomy 1913.”
Donated to the University by Robert Stebbins, grandson of Dr. Joel Stebbins.
Bigelow Kennard & Company, Boston
Found in the University Archive’s special storage, Joel Stebbins papers, RS 15/3/21.
1913
University of Illinois archives
English
physical object
University of Illinois Observatory, Urbana, Illinois
Sextant
Astronomy
Navigation
Surveying
Measuring instruments
Wood, metal, glass
Wood box, 9 7/8 x 9 7/8 x 5 ½ inch, with hinged lid, two hook latches and metal handle. Maker’s laminated paper label and university ID tag on inside. While the last inspection date on this sextant is 1939, the last sextant made with the Brandis label was 1932.
Black metal frame with wood handle. Maker’s no. 5071, also includes US Navy no. 2696, Navy certificate dated 9/18/1939. On index arm is “Brandis & Sons, Brooklyn” Included 3 black painted telescopes, vernier read with swivel magnifying lens, tangent screw and clamping arms on index arm, and threaded telescope bracket .
Brandis & Sons, Brooklyn, New York
Astronomy Department, University of Illinois, Urbana, Illinois
circa 1939
Michael Svec
Copyright Michael Svec
image/jpg
English
physical object
University of Illinois Observatory, Urbana, Illinois
Postcard, "Observatory, University of Illinois"
Astronomy
Photography
Architecture
Looking southwest toward the north entrance of the observatory.
C.U. Williams, Photoette, Bloomington IL.
Personal collection of Michael Svec
circa 1905
Michael Svec
image/jpg
English
postcard
University of Illinois Observatory, Urbana, Illinois