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One other explanation which I have seen in practice on my images is wind vibration of the camera. This can have a negligible effect on the star images since they are integrated over minutes but show up very clearly on meteors which are only present for a fraction of a second. You even see this on trailed objects like minor planets in long exposure images. If this were a real, physical effect on the meteroid itself you should be able to calculate the transverse acceleration using the amplitude of the corkscrew and the presumed range and along-track angular rate. It would be interesting to see whether this looked physically reasonable given the kind of off-track lift force that you might imagine.
And the Guardian has ‘Oumuamua on its front page today. Hmmm. And I was worried that the Daily Mail might pick it up.
John, Thanks. I guess it was slightly OTT. I’m not a great fan of Clarke’s style but “turgid” was definitely unfair. His sci-fi contains a lot of very good stuff but he concentrates on technical detail rather than characters. In any case Rama is definitely worth a read and the parallels with ‘Oumuamua are interesting. In general reading sci-fi from that era shows that we have advanced far more rapidly in some areas (e.g. computers, telescopes, imaging) than most authors expected, and far more slowly in others (manned spaceflight, politics?).
The videos of all three talks are now on the website here.
I have a copy of Coeli which I’ve owned since I bought it as a teenager in the seventies. It got very dog-eared after many damp nights outside. I don’t have these negative charts though and would be very interested in the history of these.
Yes, Rama would have been a very appropriate name, particularly because, in the book, it was the very odd lightcurve that was the first thing that drew attention to the object. A long, thin object in a strongly hyperbolic orbit. There is no indication that this isn’t a natural object but the parallels with the Clarke’s novel are quite interesting. It’s definitely worth a read if you haven’t read it already. There was also a very good Radio 4 adaptation which must be available somewhere.
Hi David. I loaded your image into Aladin (a very useful free program that you can download for free from here) and marked the position of the comet at the time of your observation (the pink cross). The faint fuzz is certainly in the right sort of position but it is difficult to be certain since it is so close to the detection limit and it could be an artefact. For very faint objects like this it is worth getting two stacks separated by 30 mins or so. When the two images are blinked any faint comets become obvious from their motion.
Anyway, this is certainly a very good attempt. Please keep trying to image this object.
Nick.
This object has been redesignated 1I/ʻOumuamua in MPEC 2017-V17. The “1I” is a new designation and it signifies that this is the first confirmed interstellar object to be detected transiting our Solar System. The pronunciation of the name is (ō’u-mu’-a-mu’-ă) and, according to the MPEC, the name is of “Hawaiian origin and reflects the way this object is like a scout or messenger sent from the distant past to reach out to us”. This is probably the first of many interstellar objects that will be discovered over the coming decades given the sensitivity of modern sky surveys.
David, yes this could be a nice comet for us since it is very well placed at its brightest. I expect it might get to tenth mag around the end of the year when the comet is racing through the circumpolar constellations. See the attached chart. We already have a few images of it in the archive and would welcome observations as it moves in to perihelion.
Nick.
I’ve just got up and processed the rest of the frames. Here is the run through the night. The data gets noisy at the end as the sky brightens and the spike just before 0.7 is not real. It looks to be a cosmic ray hit on the CCD adjacent to the star.
I’ve been following this star for the last few hours. It is a lot brighter than its catalogue mag (r=13.79) but doesn’t appear to be doing much.
Its now just on its way out of the C3 field. There’s a nice timelapse movie showing the complete pass here.
Yes, it will be interesting to watch it pass through. SOHO is getting very old now and is living on borrowed time. What will we do when it is gone?
There is indirect and rather weak evidence that some other objects may have interstellar origins but A/2017 U1 (now demoted from cometary status) has direct evidence from its strongly hyperbolic orbit. We’ve never seen anything with this kind of orbit before.
Also, in the “how far south can you see from the Canary Islands” here’s a picture of the top half of Crux on the horizon taken from La Palma.
I have a load of frames of the southern sky taken from a beach in Queensland but I’ve never got around to processing most of them since there was a lot of drifting cloud. They were all taken with a camera on a fixed tripod so the exposures are short. I have a set of Crux and I’ve uploaded one frame here. It did get a nice set of the LMC and this is the only set I have every processed. The final version is here. Timelapses of the rest are here.
Indeed some fantastic images. I particularly like the skyscape ones.
