View Full Version : GCRT J1745-3009 celestial phenomena - wide bandwidth maser

2005-Mar-12, 05:52 PM
Any speculations:

Astronomers at Sweet Briar College and the Naval Research Laboratory (NRL) have detected a powerful new bursting radio source whose unique properties suggest the discovery of a new class of astronomical objects. The researchers have monitored the center of the Milky Way Galaxy for several years and reveal their findings in the March 3, 2005 edition of the journal, “Nature”.


One important clue to understanding the origin of the radio bursts is that the emission appears to be “coherent,” Hyman said. “There are very few classes of coherent emitters in the universe. Natural astronomical masers — the analog of laser emission at microwave wavelengths — are one class of coherent sources, but these emit in specific wavelengths. In contrast, the new transient’s bursts were detected over a relatively large bandwidth.”


Trob :D

2005-Mar-14, 09:00 AM
I'm wondering why there was only five bursts. I don't know much about the transmissions of transients. Do they go through cycles, or stay somewhat constant?

2005-Mar-14, 10:36 AM
That is an interesting question...but alas I cannot answer it.

Actually I thought people would want to talk about this phenomenon, but curiously there have been no responses but yours for some reason.(maybe people have thought I was fishing for a sollution involving aliens - I was not!!!)

I'm surprised at the rarity of the phenomenon, because apparently we have been looking in this em-range for a while (not that I would know), without finding similar cases.
Are there no suggestions whatsoever about what kind of natural phenomenon could cause it - in principle????

Trob :D

2005-Mar-15, 07:28 AM
A new class of transient? Being so near the core, obscured by so much, maybe we saw effects of part of a cycle or a rare type of collision?

I don't know enough about this to come up with much. I too am curious what others think of it.

Anything I try to write about it seems to come out similar to this: :lol:

Although the exact nature of the object remains a mystery, the team members currently believe that GCRT J1745-3009 is either the first member of a new class of objects or an unknown mode of activity of a known source class.

2005-Mar-15, 08:11 AM
Just finnished reading the article. I do find this to be pretty interesting stuff.

Maybe try changing the topic to something like "Possible alien signal coming from centre of Milky Way", if you want to attract more attention. *Joking* :lol:

But the topic could probably be reworked, as it does sound like something that more would be interested in. :D

W.F. Tomba
2005-Mar-15, 09:11 AM
Yeah, the topic title is about as opaque as can possibly be. I only clicked on it to see if I was right that GCRT stood for Giant Cathode Ray Tube. Now, I suppose someone who knows enough to comment on this discovery would probably recognize that as the name of an astronomical object, but unless they happen to remember which object GCRT J1745-3009 is, they will still have no idea what the thread's about.

2005-Mar-15, 11:08 AM
Thanks for the hint folks - lets see if this expanded topic attracts some more people...


I almost wrote ALIENS - just for the hell of it :roll:

2005-Mar-15, 05:53 PM
If this source varies every 77 minutes, then it must be very small in a cosmic sense--not much larger than the orbit of Saturn. The fact that the source hasn't repeated, and had never been before observed suggests to me that it's a transient phenomenon that may be relatively rare. Meter-length radio waves are pretty weak (even if the source in toto is powerful), so it would be interesting to know how, or if magnetars can produce such a phenomenon.

I think it would be prudent to create a cheap, LF radio array designed specifically to listen in on this thing--preferably situated in the Southern Hemisphere, where the galactic center rises far overhead--that could alert radio astronomers should it ever burst again. As is, if the article presents all we currently know about the object, it may be years, or even decades before we find out what's up unless there's a repeat.

2005-Mar-19, 04:49 PM
Given the frequency of the emission, around 330 MHz, I find it interesting that there were exactly five pulses received.Five times 330 MHz puts us very near the hydroxyl lines. Given the wide bandwidth of the emission, some part of it may be exactly one fifth of one or more of the hydroxyl lines. It is not entirely clear if the period of observation was long enough to allow more than five pulses to be received or not, nor that any of this is anything but a coincidence. Apparently some nulling pulsars can turn themselves off for periods similar to that pulses given off by the 'burper', but a pulsar would be expected to show pulses of a period of around 1 second, or less within the 10 minute duration pulses.This was not reported.