Page 1 of 1

Are there any known optical or psychological illusions...

Posted: 03.09.2013, 20:51
by PlutonianEmpire
That, when looking at a star through a telescope, the star appears to flash?

I know it wasn't the twinkling caused by our atmosphere, but I don't know if I was imagining it, but the star I was looking at last night actually appeared to flash, with a greater brightness variation than the twinkling seen by the naked eye.

I don't know if it was a passing satellite, or a passing airplane with its strobe lights on, but I don't recall seeing a plane-ish shape go through my FOV, and I don't know if an overhead satellite crossed the FOV fast enough to look like crappy framerates on a 3-D computer program.

For the record, I was using a telescope with a 4.5" mirror, and the eyepiece was 15mm, although I was wearing my eyeglasses at the time, so I adjusted the focuser a bit more to compensate. The star is near +5 apparent magnitude. It was also past midnight, between 00:00 and 00:30 (05:00 and 05:30 UTC).

So, any idea on why a star would appear to flash? The length of the flash appeared to be approximate or slightly less to that of a camera's flash.

And no, no aliens, I'm sure it's terrestrial in origin. I just don't know what.

Any ideas?

Re: Are there any known optical or psychological illusions..

Posted: 04.09.2013, 06:14
by PlutonianEmpire
lodgy wrote:
PlutonianEmpire wrote:That, when looking at a star through a telescope, the star appears to flash?
In first : latitude and longitude help us to locate strongly already on the celestial vault.
This is the minimum for an "amateur astronomer". :roll:
Failing that, azimuth and elevation from your coordinates with your GPS.
Right. My bad. I'm a bit absent-minded myself. Anyways, here's the location info I'm using in Celestia for the "town" I live in:

Code: Select all

LongLat [ -93.560640 45.331759 0 ]
(93°W, 45°N, to oversimplify it). Outskirts of Minneapolis, to the NW.

PlutonianEmpire wrote:And no, no aliens, I'm sure it's terrestrial in origin. I just don't know what.
Any ideas?

In second : tell us exactly the date and time of your....vision in UTC time of course. :)
I already did in the OP. ;)

PlutonianEmpire wrote:It was also past midnight, between 00:00 and 00:30 (05:00 and 05:30 UTC).
(The 00:00 and 00:30 represented the time displayed in my timezone, obviously.)

Re: Are there any known optical or psychological illusions..

Posted: 04.09.2013, 16:41
by PlutonianEmpire
I was looking at HIP 10644, Aka, Delta Trianguli, when the star itself appeared to seemingly flash. My first thought was a binary-induced nova, since it is a close binary, but I immediately remembered novas last a heck of a lot longer than half a second; not to mention both stars are still in the main sequence.

So, I posted because I wasn't sure if my eyes or mind were playing tricks on me, or something else, and I was curious if there was a term for it all.

Re: Are there any known optical or psychological illusions..

Posted: 05.09.2013, 02:27
by PlutonianEmpire
That's what I thought too, a Geostationary, but after checking Celestia, using the Geostationary satellites as a generic example, which showed the active satellites in their Geostationary orbits, and the "dead" ones slowly drifting into Geosynchronous orbits beginning to follow the ecliptic line. From the vantage point of my location, HIP 10644 had an average angular separation from the Geostationary and Geosynchronous satellites of about 40, 45 degrees.

Although at midnight, it's kinda hard, especially this close to equinox, for at least LEO (Low Earth Orbit) satellites to reflect sunlight, but the only alternative satellites, that I can think of, are the highly eccentric polar ones, which would put them high enough out of the Earth's shadow. I think.

Re: Are there any known optical or psychological illusions..

Posted: 06.09.2013, 02:26
by John Van Vliet
--- edit----

Re: Are there any known optical or psychological illusions..

Posted: 06.09.2013, 03:44
by PlutonianEmpire
Well, I do wear eyeglasses to see, since I'm a little bit near-sighted, so possibly a scratch there as well, and I was wearing them at the time.

Re: Are there any known optical or psychological illusions..

Posted: 06.09.2013, 05:04
by John Van Vliet
--- edit----

Re: Are there any known optical or psychological illusions..

Posted: 07.09.2013, 04:19
by PlutonianEmpire
That might've been it.

I think I recall a similar event last fall or the year before when observing the same star with a different telescope, which was a refracting telescope. I've had that one since the 1990's, so I just dismissed it as a fluke, either from a scratch on any one of the lenses, or on my eyeglasses, mainly because of the telescope's age.

Anyways, thanks for the help. :)

Posted: 29.10.2016, 13:07
by CharlottAwong
Well, there can be multiple explanation for the issue. Maybe there are some shining rocks (formed by an explosion) are passing by. Or there could be internal reaction of the star. Or any other major event in nearby universe that is showing the phenomena.