The Planetary System of Zeta 2 Reticuli by Robert Teague email: rteague@bellsouth.net zeta2ret.txt is copyright 1997 RGT The star Zeta 2 Reticuli has been of interest to ufologists for many years, ever since Marjorie Fish identified it as the home system of the aliens who met the Hills in 1961, based on an analysis of the star map Betty Hill reproduced. Both Robert Lazar and Falcon later confirmed this star as the home of visiting aliens. In astronomical journals, it has been included in studies over the years, and a detailed analysis resolving some unusual observations was published in 1987. Oddly, an examination of various UFO-related web sites, Usenet articles, and books leads to only the most cursory mentions of the star. Nowhere has a detailed study of the 'planets' claimed been made, and that is the lack addressed here. It is not my intention to debate the existance of the Greys, but to address the astronomical and astrophysical questions. Since there has been no mention of planets beyond the fourth one, I have not calculated for any. Robert Lazar's naming convention is used, instead of the one used by astronomers. This is deliberate--it references the fact that the inner two companions are retracted claims made by astronomers, and there is no astronomical evidence for the existance of the outer two. For our purposes, the retractions have been set aside, and the planetary conditions described by Falcon and Lazar assumed to be accurate. The Star Zeta 2 Reticuli (hereafter Z2R) is a G1V star, very similar to our G2V sun, and therefore a good candidate for having an earthlike planet. The Hipparcos Astrometry Satellite recently completed its mission to determine accurate distances for over a hundred thousand stars. Z2R was one of them, and from the published catalog we have a parallax of 0.08279. This indicates a distance of 39.394 light years, a bit further away than is normally indicated, but within the range of previous measurements. Astronomical studies that include Z2R give data that can be assembled into set of physical parameters for the star. It should be noted that some of the figures given are calculated, and not direct measurements. Table 1: Physical Parameters for Zeta 2 Reticuli Parameter in metric units in Solar units comment Mass: 2.0035e30 kg 1.0072 calculated Radius: 686643 km 0.9866 observed Density: 1.47 g/cm cu 1.0439 calculated Gravity: 283.542 m/sec sq 1.0348 observed Temperature: 5930 K 1.026 observed Luminosity: 4.1265e33 1.0783 calculated The star is 6-8 billion years old, and has some unusual features, like a higher surface gravity than is normal for its type, and twice the amount of helium our sun has. The excess helium has slowed the star's evolution across the main sequence, and causes a high ultraviolet output. Commentary on Measurements We do not, as yet, have spectroscopic data on the composition of extrasolar planets. We do, however, have theoretical models for a variety of masses, compositions, and distances from the star. This allows one to calculate a set of physical parameters for the planets, depending on the model used. Knowing the brightness of Z2R, the amount of light reaching a planet can be determined, and therefore the effective temperature. It should be noted that the effective temperature is not the same as the surface temperature. Factors such as the atmosphere's reflectivity, depth, composition, and the planet's rotation period can make a great difference at the surface. Isaac Asimov once formulated what he called the "tug-of-war" ratio. This is the ratio of force exerted on a moon by its primary and its sun. As long as the ratio is greater than 1, the planet wins the battle, and keeps the moon. He noted that in the solar system, natural satellites occur where the ratio is greater than 30. He set the inner limit at the planet's Roche Limit. He discovered the Earth loses the battle to hang onto the Moon, as the ratio is 0.45. He also discovered that Mercury's moon formation limit is inside its Roche limit, and Venus' is only a few thousand kilometers wide. The Asimov Ratio has been calculated for Z2R's planets. The radius of restrained rotation, where a star's tidal forces have slowed a planet's rotation so it always presents one face to the sun, may be calculated based on the planet's distance from the sun and its radius, and the age of the system. The Titius-Bode Law The Titius-Bode Law, first formulated in the mid-1700s, predicts the distances of the planets from the sun. There has been much controversy over the centuries about the Law, whether it is an actual law, or just a numerical coincidence. As usually given, it does have problems, seeming to fail at Neptune and Pluto. Research since 1987 has led to the physical explanation of the Law, and a modified version that not only predicts all of the planets, but all of the moons, and even the planets of pulsar PSR1257+12. Application to the other known extrasolar planets has not yet been made. As a detailed discussion of the Law is outside the scope of this paper, suffice here to say that it has been applied to Z2R, and distances to the 'known' planets determined. Reticulum 1 In 1996, a planet was announced by the European Southern Observatory. A few days later, the announcement was retracted. The discovery was made as part of the Planetary Search Program ongoing since 1992, using a high-precision radial velocity shift method to look for planets. The program consists of 27 F, G, and K stars. (Alpha Centauri A and B, and Proxima are part of the program.) The detection limit for Z2R is 14 meters/second. Reticulum 1 imposes a variation of 22.6 m/sec and a period of 18.9 days. (For comparison, Jupiter imposes on the sun a radial velocity of ~12 m/sec and a period of 11.86 years.) In determining the planet's mass, the star was assumed to have a mass of 1.025 sun, based on its spectral type's place on the main sequence. As can be seen, the star's mass as computed is slightly less, leading to a different outcome. Table 2: Radial Velocity data Originaly This Work Notes Radial Vel.: 22.6 m/sec 22.6 m/sec detected Planet Mass: 0.27 Jupiter 0.297 Jupiter calculated Inclination: 90 deg. 90 deg. assumed Period: 0.0517 year 0.0517 year detected Distance: 0.14 AU 0.1391 AU calculated Star Mass: 1.025 sun 1.0072 sun assumed/calcuated The physical, orbital, and energy parameters have been determined, based on well-known astrophysical equations, and the results given below. Table 3: Reticulum 1 Mass: 5.653e26 kg Radius: 47671 km Density: 1.2457 g/cm/cu (assumed same as Jupiter) Gravity: 16.5 m/sec sq Orbital Period: 18.9 days Orbital Distance: 0.1391 AU Orbital Speed: 80 km/sec Rotation Period: 18.9 days Roche Limit: 116318 km Asimov Distance: 63928 km Constant: 75,834,517 erg/sec Albedo: 0.52 (assumed same as Jupiter) Eff. Temp.: 632 K (679 F) It is noted that the Asimov Radius is inside the Roche Limit, so it is unlikely the planet has any moons. Reticulum 2 In 1980 a companion to Z2R was announced, discovered in a program of speckle interferometry measurements to look for binary stars, and also determine star diameters. The 'companion' was resolved in the 3.6 meter telescope in 1978, but not seen in a second run in 1979. In the 1987 paper which gave a detailed analysis of Zeta 1 and 2, the companion was dismissed as an artifact of the telescope's spider. Perhaps this was actually the first direct sighting of an extrasolar planet. Improbable, but not impossible, and the following facts support the idea: 1. The companion was separated from the star by 0.046 +/- 0.006 arc seconds. At Z2R's distance, this is 0.556 +/- 0.0725 AU. The Titius-Bode Law predicts a distance of 0.591 AU for a companion. 2. The Hipparcos Satellite was capable of detecting an companion of brown dwarf mass (~80 Jupiters) or higher, but found none for Z2R. The radial velocity technique would have found a companion of greater than 0.368 Jupiters at that distance. This eliminates the sighting as a star or brown dwarf. 3. Between the first sighting in 1978 and the second attempt in 1979, there were ~334 days. A distance of 0.556 AU means an orbital period of 144.33 days. This is ~2.3 orbits, so at the time of the second run, the companion was nearly in front of (or behind) the star, making it impossible to see. This also argues for a high inclination angle, meaning low masses for the planets, assuming all are coplanar. 4. A planet shines with reflected sunlight. The magnitude depends on the distance from the star, the brightness of the star, the diameter of the planet, and the albedo (fraction of light reflected). The limiting magnitude of the 3.6 meter telescope was +24 at the time the program was run. A planet with the same albedo as Venus, shining at 2.0e-7 the star's brightness, would be seen as a +22 magnitude object, above the limit. At a distance of 0.556 AU and a radius of ~4.3 earths, Reticulum 2 is very close to the radius of restrained rotation. Table 4: Reticulum 2 Mass: 1.0612e26 kg Radius: 27295 km Density: 1.245 g/cm cu (assumed same as Jupiter) Gravity: 9.5 m/sec sq Orbital Period: 0.3592 year (144.33 days) Orbital Distance: 0.556 AU Orbital Speed: 41.9 km/sec Roche Limit: 66601 km Asimov Radius: 110714 km Constant: 4,746,479 erg/sec Albedo: 0.65 (assumed same as Venus) Eff. Temp.: 292 K (67 F) There is a chance this planet has moons. Reticulum 3 Almost nothing has been said about Reticulum 3, which would normally mean that only the most general data can be determined, including only an upper limit to the mass. Falcon indicated the saucers he had seen were from this planet, but the conditions he described fit Reticulum 4. To reconcile this, perhaps Reticulum 3 is a terrestrial planet (in the same sense as Mars is a terrestrial planet), and has been colonized. We will assume this is correct, and the planet is a physical twin of the Earth. Table 5: Reticulum 3 Mass: 5.97424e24 kg Radius: 6378 km Density: 5.496 g/cm cu Gravity: 9.799 m/sec sq Orbital Period: 0.797 year (291.4 days) Orbital Distance: 0.8625 AU Orbital Speed: 32.2 km/sec Roche Limit: 15562 km Asimov Radius: 40739 km Constant: 1,972,436 erg/sec Albedo: 0.367 (assumed same as Earth) Eff. Temp.: 272 K (29.9 F) The effective temperature is some 30 degrees warmer than Earth's, which is at variance with Falcon's statements. Reticulum 4 From Falcon we learn that the planet is physically similar to Earth, but colder, with a thinner atmosphere, and a higher proportion of helium and argon. From Robert Lazar we learn the day is "about 90 hours long". Concerning the presence of helium: if gravity was the only factor to consider, the Earth would be able, barely, to hang onto its helium. The sun warms the helium enough for it to trickle away into space. The colder Reticulum 4 would more easily hang onto its helium. The heavier argon, which is ~1% of the Earth's atmosphere, would not be affected. A day on Reticulum 1 is the same as its year, 453.6 hours. A day on Reticulum 4 of 90 hours, 43 minutes, and 12 seconds is exactly 1/5 as long. The rotation periods of the two planets is tidally locked. It's likely, given the age of the system, that planets #2 and #3 are locked as well, but we have no data concerning rotation periods for them. In the absence of exact numbers, we will again assume a physical twin of Earth for the planet. Table 6: Reticulum 4 Mass: 5.97424e24 kg Radius: 6378 km Density: 5.496 g/cm cu Gravity: 9.799 m/sec sq Orbital Period: 1.659 years (606.177 days) Orbital Distance: 1.405 AU Orbital Speed: 25.2 km/sec Roche Limit: 15562 km Asimov Radius: 66387 km Rotation Period: 3.78 days Local Days in year: 160.364 Constant: 743,307 erg/sec Albedo: 0.367 (assumed same as Earth) Eff. Temp.: 213 K (-76 F) Planets Beyond? Nothing has been said about planets further from the star than Reticulum 4, so I will refrain from speculating beyond this one comment. The 'ice point', the free space temperature beyond which ice grains can exist, where traditional gas giant planets are thought to form, is at 3.14 AU. A Kuiper Belt or Oort Cloud would be beyond this distance. Comments Some time after Reticulum 1 was retracted, I contacted Jean Schneider, who maintains the Extrasolar Planets Encyclopedia, and asked why it was removed. He replied the radial velocity variation was due to oscillation of the star, rather than a planet. Oscillations can fool a radial velocity measurement, by making the star pulse, and changing the shape of the spectral lines being measured. A quote from the paper announcing the discovery of 51 Pegasi's planet may be instructive here: "Among solar-type stars no mechanisms have been identified for the excitation of pulsation modes with periods as long as 4 days." Reticulum 1's period is 18.9 days. Concerning the retraction of Reticulum 2: several hundred stars were studied in that program, and the results published in several follow-up papers over the years. Zeta 2 Reticuli is the only star I could find to have its companion retracted. Conclusion After an examination of the various claims of companions for the ufologically important star Zeta 2 Reticuli, we find the information given is consistant with the astrophysical conditions of the space near it. A numerical link between Reticulum 1, claimed by astronomers, and Reticulum 4, claimed by Robert Lazar, is noted. Table 7: Composite data for the planetary system of Zeta 2 Reticuli The Star: ---------------------------------------------------------------------------- Spectral Type: G1V Mass: 2.0035e30 kg Temperature: 5930 K Distance: 39.394 ly Radius: 686643 km Luminosity: 4.1265e33 erg/s Age: 6-8 billion years Density: 1.47 g/cm cu Visual Mag: 5.3533 Gravity: 283.542 m/sec sq Physical Data (in Earth units) Reticulum 1 Reticulum 2 Reticulum 3 Reticulum 4 ---------------------------------------------------------------------------- Mass: 94.6 17.7 1.0 1.0 Radius: 7.4 4.3 1.0 1.0 Density: 0.2 0.7 1.0 1.0 Gravity: 1.7 0.97 1.0 1.0 Orbital Data ---------------------------------------------------------------------------- Distance (AU): 0.139 0.556 0.862 1.405 Period (days): 18.9 144.33 291.4 606.1 Speed (km/sec): 80 41.9 32.2 25.2 Roche Limit (km): 116318 66601 15562 15562 Asimov Rad. (km): 63928 110714 40739 66378 Rot. Per. (days): 18.9 --- --- 3.78 # days in year: 1 --- --- 160.364 Energy Data ---------------------------------------------------------------------------- Constant: 75,834,517 4,746,479 1,972,436 743,201 Albedo: 0.52 0.65 0.367 0.367 Eff. Temp. (K): 632 292 272 213 References Zeta 2 Reticuli: Home System of the Greys? The framing paragraphs are not signed, but the bulk of the article, credited to Joe LeSesne, was actually several Usenet posts written by Carole Lepilleur. Found on DejaNews The Zeta Reticuli Star System by M. Collins and William Moore Found on DejaNews Dr. Bob Lazar, Los Alamos Physicist and UFOlogist by M. Hines Found on DejaNews The Zeta Reticuli Incindent by Terrence Dickenson with related commentary by: J.L. Kretsch, C. Sagan, S. Soter, R. Schaffer, M. Fish, D. Saunders, and M. Peck Sky & Telescope 1976 Asimov on Astronomy by Isaac Asimov Chapter 9: "Just Mooning Around" Speckle Interferometry Measurements of Binary Stars by D. Bonneau, A. Blazit, R. Foy, and A. Labeyrie Astronomy and Astrophysics Suppliment Series v42 p185 Nov. 1980 Catalog of Apparent Diameters and Absolute Radii of Stars (CADARS) by M. Fracassini, L.E. Pasinetti, and F. Manzolini Astronomy and Astrophysics Suppliment Series v45 p145 July 1981 The Temperature Scale of Solar-Type Stars by T. Gehren Astronomy and Astrophysics v100 p97 1981 Zeta 1 and Zeta 2 Reticuli: A Puzzling Solar-Type Twin System by L. Da Silva, and R. Foy Astronomy and Astrophysics v177 p204 1987 A Jupiter-mass Companion to a Solar-Type Star by M. Mayor and D. Queloz Nature v378 p355 1995 Giant Planets at Small Orbital Distances T. Guillot, A. Burrows, W.B.Hubbard, J.I. Lunine, and D. Saumon Astrophysical Journal v459 L35 March 1996 The ESO Planetary Search Program: Preliminary Results by A.P. Hatzes, M. Kurster, W.D. Cochran, K. Denneri, and S. Dobereiner Journal of Geophysical Research 101, E4, p9285 Apr. 25 1996