dgary@ecsvax.UUCP (01/31/86)
The 24 January issue of SCIENCE has a fascinating article on weird terrestrial events associated with an astronomical x-ray source in the constellation Cygnus, the swan (sometimes called the Northern Cross). Cygnus X-3, some 37,000 light years away, is one of the the most luminous objects in our galaxy. Long interesting to astronomers, it has recently attracted the attention of particle physicists thanks to some evidence it may be showering earth with a hitherto totally unknown kind of particle. Proton-decay experiments at various locations (principally at the Soudan Mine in Minnesota) have turned up anamolous muon showers possibly associated with Cygnus X-3. Not only do they seem to be coming from the right direction, they are in phase with the object's radio and x-ray emissions (which have a 4.79 hour period presumed due to Cygnus X-3's being part of an eclipsing binary). Unfortunately, the numbers are too small to be completely convincing. If the showers are really connected with Cygnus, something odd is going on. The directionality and synchronization with the photon pulses point to an uncharged (so it isn't diverted by the galactic magnetic field), speed-of-light (so it can stay in phase) particle. Most candidates are way too short-lived (the muons are themselves, and so presumably they are secondary particles). Neutrinos are ruled out by the fact that the particles don't seem to penetrate the Earth. We know how many photons there are and it isn't enough (by two orders of magnitude). So is the phenomenon real or bogus? Recently an air-shower detector atop the Haleakala volcano on Maui has produced new evidence. Designed to detect Cherenkov radiation from particles hittin the upper atmosphere, it saw (on 12 October) a spectacular shower from Cygnus X-3 lasting a full minute. (A typical cosmic ray shower lasts a nanosecond.) If these observations turn out to be true, they could be very important. It has been suggested that the Cygnus X-3 pulsar is not a neutron star but rather a large lump of quark matter 10 km across. Quark matter would only be possible if a large number of strange quarks are present. (Strange quarks contribute stability; that's why they're called "strange," in fact.) It's possible the muon showers are caused by hypothetical di-lambda (or H) particles proposed by Robert Jaffe of MIT in 1977. This particle is made of two up quarks, two downs, and two stranges. If it turns out to be the culprit, it is still probably not what Cygnus X-3 is emitting. Suggestions are that chunks of quark matter are being knocked off the pulsar and are producing Hs in the atmosphere of its companion. All this is fascinating but speculation nonetheless. For more details see Science or Phys. Lett. v160B p181 (1985) or Nature v317 p409 (1985). -- D Gary Grady Duke U Comp Center, Durham, NC 27706 (919) 684-3695 USENET: {seismo,decvax,ihnp4,akgua,etc.}!mcnc!ecsvax!dgary