The bulk of the effort to locate an extraterrestrial signal has been concentrated in the microwave frequencies of the electromagnetic spectrum. A great deal of the effort has also been made for over on hundred years recording the magnitude of variable stars.
One star, designated as R. Coronea Borealis has received considerable attention ans observations have been made from 1842 to date (ref. 1). This particular star is one of a class of carbon stars, of which there are about 3 dozen in this galaxy. The variation in magnitude varies from 6 to below 14. Virtually every book on the subject of variable stars reports the visual light curve of R. Core. Bore. since it is unusual.
Surprisingly, when certain segments of the R. Core. Bore. curve are compared with the Infrared spectra a number of organic compounds, the patterns are quite similar! The IR spectra were determined in many analytical laboratories on Earth. This fact was first reported in 1993 (ref. 2). The expert spectroscopist becomes able to identify at a glance from the unique pattern which every molecule has.
This latter observation is critical to the above since no wavelengths are revealed by the recording of the visible light curve from a variable star, merely the magnitude and time of the observation. The pattern thus shown is the key element.
As shown in figures 1-4, the light curves have been transformed to a plot giving % transmission versus wavelength. The relevant IR curve is given beneath each example for comparison. The key pattern known as the signature band is given for each case.
 Figure 1A gives the light curve from 1915 to 1925 which is recognizable as the band pattern of a nylon type polymer, or that of a secondary amide. Fig 1B is the spectrum of a nylon for comparison. The signaure bands are the cluster between 6 and 7 microns, and 3.0 - 3.5. The band intensities are comparable in Fig 1A and 1B.
 Fig. 2A shows the R. Core Bore. light curve from 1934 to 1940. The curve is immediately recognized as that of a gas due to the triplet of bands near 3.4 microns, termed P-Q-R. Gas specra are the only possessed of this feaure. A second set at longer wavelength is similar but lacking the Q branch. The nearest match is the IR spectrum of methane.
 The third example is the spectrum of RCB from 1942 to 1950. The curve is recognizable as an olefinic hydrocarbon posessing at least two unsaturated types as the complex band at 10 - 11.25 microns. This feature is confirmed by the two small bands near 6 microns, and the single band at 5.5 microns which is an overture of the longer wavelength bands. Fig. 3A is very similar to Fig. 3B, the IR spectrum of butadiene dimer.
 The 4th example is the RCB light curve from 1960 to 1966. This is recognizable as the IR curve of cellulose acetate. The signature band is the entire sectrum, Fig. 4B. The bands are due to CH, C-O-C and ester liniages. It does not fit the sectrum of cellulose.
The interpretation of the RCB data can be seen as information pertaining to a planet about RCB. Taken at face value, the IR curves suggest a star 7,000 light years distant with life similar to Earth. Cotton acetate, nylon or similar polymer, methane gas, and an olefin similar to isoprene. No water spectrum or carbon dioxide were detected.
The examination of other variable stars is in progress and will be published in detail.
References:
1. a. M. Petit, Variable Stars, 1993, John Wiley
b. Sterken and Jascheck, Light Curves of Variable Stars, Cambridge Univ. Press 1996
c. AAVSO Series of Monograhic re Variable Stars, Cambridge, Mass. AAVSO Press
2 W. L. T., Laser Focus World, p67, Jan 1993 |
