First system of multiple planets found around a sun-like star
"...But now that we *see* three around the same star, it is hard to imagine anything else." Best to keep in mind that nobody "sees" anything in this research. It's all based on an analysis of "wobble" that is detected in the rotation of the subject stars. Then a bunch of number crunching (computer modeling) that in turn hypothecates "planet" size and location.
"One big question left to answer is how such a solar system arose. "The usual picture is that gas giant planets can only form at least four AU away from a star, where temperatures are low enough for ice to condense and begin the process of planet formation," said Brown. "But all three giant planets around Upsilon Andromedae now reside inside this theoretical ice boundary." The planets may have formed close to the host star, or, like balls on a billiard table, the planets may have scattered off of each other, migrating into their current orbits from a more distant place of origin."
Well here we go
again space fans. Seems like every which way we look this old universe of ours
just doesn't want to cooperate with the Big Bang Model. This particular situation
is a very sweet outcome, however, given Butler and Marcy's path to fame. Early
in 1997 an email from "two astronomers" sweep through the Internet. Seems that
the two astronomers switched from their usual observations to have a look at
a new wondrous object in the sky called Hale-Bopp, and they saw and reported
to their close friends in the astronomy community some unusual things like the
number of objects, size, etc. The email told what then happened to them. Seems
some unidentified "officials" showed up at their office, confiscated their computers
and records and told them to look someplace else in the sky. Butler and Marcy,
working out of the modest Lick Observatory on Mt. Hamilton (San Jose), CA were
widely rumored to be the "two astronomers". Yours truly (at the time) found
Butler and Marcy's cozy "family and friends" web page, but couldn't get them
to answer any emails, or phone calls. Also at the time "planets" around other
stars had not been "observed" or even believed to exist. Then about two to three
months later a big "planets around other stars" announcement was made by NASA/Butler/Marcy
quickly followed by equally big time dissent from other astronomers. NASA then
sponsors and broadcast an hour long video on PBS featuring (drum roll) Butler,
Marcy, and their "Planets around other stars". (Butler and Marcy look very uncomfortable
in their NASA regulation "I am a scientist" lab coats, suits and ties.) And
as if this wasn't enough to seal the deal, Butler and Marcy wind up a few weeks
later as the feature article, front page, Sunday edition of nothing other than
the "New York Times". (Dissent fades) We can also see from the current story
that Butler has upgraded from Lick Observatory to the Anglo-Australian, and
the grant money must be rolling in. Coincidence? Maybe. Maybe not. Yours truly,
Note from Jim McCanney:
I liked your article on the discovery of new planets. I read about this in the paper but haven't see any "hard data" yet. The data should, or probably will, reveal that the "astronomers" are really out in lala land. The periods of these objects are running in number of days, whereas Jupiter has a period of 10 years. The distance from the central star data means that they would be inside the orbit of Mercury. This is an impossibility for an object that size, and further means that there could not be a gas planet in that close position because the central star would suck off its atmosphere. If the "planet" were solid the tidal forces would break it up even if it did form elsewhere. They are trying to massage the data to make it support the Big Bang model. One of these "planets" is supposed to have an orbital period of only 4 days. Can you imagine little Mercury zipping around the sun in 4 days? Now imagine a planet of 10 Jupiter masses? These guys are nuts! So much for NASA/Goddard's peer review program. How could they let this out as "truth"?
FLORIDA TODAY Space Online
April 15, 1999
First system of multiple planets found around a sun-like star
A San Francisco State University news release
SAN FRANCISCO - Astronomers from four research institutions have discovered strong evidence for a trio of extrasolar planets that orbit the star Upsilon Andromedae. This is the first multiple planet system ever found around a normal star, other than the nine planets in our solar system. The closest planet in the Upsilon Andromedae system was detected in 1996 by San Francisco State University (SFSU) astronomers Geoffrey Marcy and R. Paul Butler. Now, after 11 years of telescope observations at Lick Observatory near San Jose, Calif., the signals of two additional planets have emerged from the data. Therefore, Upsilon Andromedae harbors the first planetary system that is reminiscent of our own solar system.
In parallel, astronomers from the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass., and the High Altitude Observatory (HAO) in Boulder, Colo., have independently found the two outer planets around Upsilon Andromedae. This team has been studying the star for more than four years at the Smithsonian's Whipple Observatory near Tucson, Ariz.
This first planetary system, found from a survey of 107 stars, offers the first suggestion that planetary systems like our own are abundant in our Milky Way Galaxy, which contains 200 billion stars. SFSU researcher Debra Fischer said, "It implies that planets can form more easily than we ever imagined, and that our Milky Way is teeming with planetary systems."
The innermost (and previously known) of the three planets contains at least three-quarters of the mass of Jupiter and orbits only 0.06 AU from the star. (One "AU" equals the distance from the Earth to the sun). It traverses a circular orbit every 4.6 days. The middle planet contains at least twice the mass of Jupiter and takes 242 days to orbit the star once. It resides approximately 0.83 AU from the star, similar to the orbital distance of Venus. The outermost planet has a mass of at least four Jupiters and completes one orbit every 3.5 to 4 years, placing it 2.5 AU from the star. The two outer planets are both new discoveries and have elliptical (oval) orbits, a characteristic of the nine other extrasolar planets in distant orbits around their stars.
No current theory predicted that so many giant worlds would form around a star. "I am mystified at how such a system of Jupiter-like planets might have been created," said Marcy, SFSU's distinguished professor of science. "This will shake up the theory of planet formation." Robert Noyes, a professor of astronomy at Harvard-Smithsonian CfA and a member of the CfA-HAO team, said, "A nagging question was whether the massive bodies orbiting in apparent isolation around stars really are planets, but now that we see three around the same star, it is hard to imagine anything else."
Currently a staff astronomer at the Anglo-Australian Observatory, Butler, an American, is the lead author of the paper, submitted to the Astrophysical Journal, announcing the triple planet system. Along with Marcy, Fischer, and Noyes, the authors include Sylvain Korzennik, Peter Nisenson, and Adam Contos of the Harvard-Smithsonian CfA, and Timothy Brown of the HAO. "Both of our groups found essentially the same size and shape for the orbits of the companions," said Korzennik. The chances of this happening by accident are infinitesimal." Added Fischer, "This is an extraordinary finding and it demands extraordinary evidence. Having two completely independent sets of observations gives us confidence in this detection."
Marcy and Butler had suspected that there was something strange about Upsilon Andromedae. The velocity variations that revealed the closest planet to the star in 1996 had an unusual amount of scatter. Not until early this year had enough observations been made of the star to confirm the presence of an additional planet, which explained some of the confusing pattern in the data. But another object still seemed to be tugging on the star. "We looked at the two planet solution that we had been expecting and there was still too much extra noise," said Fischer. "We arrived at the conclusion that the extra observed wobble could only be explained by the presence of a third planet." Both teams of astronomers considered astrophysical effects that could mimic the velocity signature from these planets, but no such effects are viable. A computer simulation by Greg Laughlin of U.C. Berkeley suggests that these three giant planets could co-exist in stable orbits.
One big question left to answer is how such a solar system arose. "The usual picture is that gas giant planets can only form at least four AU away from a star, where temperatures are low enough for ice to condense and begin the process of planet formation," said Brown. "But all three giant planets around Upsilon Andromedae now reside inside this theoretical ice boundary." The planets may have formed close to the host star, or, like balls on a billiard table, the planets may have scattered off of each other, migrating into their current orbits from a more distant place of origin.
The discovery of this multiple planet system suggests a new paradigm for planet formation where many small seed planets known as planetesimals might develop in the disk of matter surrounding a star. Those planets that grow fastest would engage in a gravitational tug of war that weeds out some of the smaller worlds and determines which planets ultimately remain in orbit.
"The Upsilon Andromedae system suggests that gravitational interactions between Jupiter-mass planets can play a powerful role in sculpting solar systems," said Butler.
If these Jupiter-mass planets are like our own Jupiter, they would not be expected to have solid Earth-like surfaces. But, Nisenson noted, "Our observations can't rule out Earth-sized planets as well in this planetary system, because their gravity would be too weak for them to be detectable with present instruments."
A bright star visible
to the naked eye starting this June, Upsilon Andromedae is 44 light-years away
from Earth, and it is roughly 3 billion years old, two-thirds the age of the
Sun. This star should make an ideal target for NASA's upcoming Space Interferometry
Mission (SIM). Expected to launch in 2005, SIM will spend five years probing
nearby stars for Earth-sized planets and will test technology slated for future
planet-searching telescopes. The ongoing ground-based planet search will enable
SIM to home in on those stars most likely to harbor small planets.