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What is this black thing?

Posted: Mon Mar 21, 2005 5:00 am
by ETX_90
A "black beast" (quoting Boldra) made an appearance on the Siding Spring concam on Saturday the 19th. Here it is:

Image

What is this?

It seems to move slowly throughout the night, as seen in the movie.

It looks like the shadow of something or some stray object that landed on the camera lens. It is yet to reappear, so it has either moved away or is just waiting to make its reappearance on another night.

Does anyone have an idea about what this strange object could be?

Posted: Mon Mar 21, 2005 11:05 am
by Boldra
I hadn't noticed the movement until I saw your comment, but I have three suggestions:
o it's a tarp or a tent, set up quite near the camera.
o it's a piece of paper very near the camera
o it's a leaf.

I think I've seen car headlights in this direction (south) on other pictures, so it could be something in the car park.

It's also worth noting that Siding Spring has been showing old images for a week before this suddenly appeared. It's entirely possible the person who fixed it intentionally placed a piece of paper in view so he could see if the images were new.

As above with downtime, but it's also Autumn, so the leaf has been sitting there for a week, and only after the server was fixed was it noticed. The shape looks a bit too regular (man-made) for a leaf though.

It looks a little blurrier than the background, which suggests it's closer, but not much. This would support the carpark tarp theory, but in that case, it's very large.

I don't think it's anything to worry about. It's not there on the Monday night (21/3/5) pics. I think the only way we could find out for sure is to ask the observatory staff.

Boldra

How big is it?

Posted: Mon Mar 21, 2005 9:54 pm
by Boldra
As an mental exercise, I poked around in Starcalc (http://www.m31.spb.ru/StarCalc/main.htm), to identify some of the stars. I'm pretty sure that the circled star below is alpha pavonis:
Image
Which at 17:44 UT was 35° above the horizon. Using this angle, we can do a little bit of Trigonometry to get some idea of its size...
Image
(I get naming rights, don't I?)
Which, unless I've completely forgotten my high school trig, should give us:

tan 35° = h/d
or, solving for h:
h = 0.7 x d

Which suggests that if the beast is 2 meters away, it must be 1.4 meters tall, or if it's 50 meters away (carpark), then it's 35 meters tall, plus the height of the building. This tells us the thing must be close or huge.

My guess is that it must be at least 2 meters away, or it would be blurrier, and if it's not on the roof with the camera, it has to be monstrous.

Have we got the first nargun on film?

Boldra
--
updated: fixed speelling of Pavonis

Posted: Tue Mar 22, 2005 2:40 am
by RJN
Interesting puzzle! My guess is that it is piece of insulation around the CONCAM that has come loose. Hopefully Andre Phillips at Siding Sping will tell us the real answer!
- RJN

Posted: Tue Mar 22, 2005 3:05 am
by ETX_90
Looking over the images and movie again, I have found a few more minute details that could have something to do with uncovering the object's origin. Here's a list of what's been mentioned so far (plus my new discoveries), listed from most likely to most outlandish, starting with most likely. Click here to look at the movie for reference to the list.

1)The object is most likely a shadow or something on or nearly on the lens, or it wouldn't be moving the way it is. In other words, it's probably not an actual object looming over the camera lens.

2)The object could be something blowing in the wind (like a piece of insulation mentioned by RJN). Notice that the shadow or whatever it is starts to move quicker when the sun starts to rise. If you've ever noticed, the wind usually starts to pick up during the daytime.

3)If you watch the movie closely, you can see that the very bottom right end of the object moves up and over, suggesting that maybe the object is rotating. Also, the top portion moves down and to the left instead of just to the left, which would also suggest a rotating object.

4)The object has a couple of small notches in it on the right side. I don't know why this would contribute to the mystery of this topic, but I listed it anyway.

5)It could be the shadow of a rotating portable solar panel :?: . This is very unlikely, but it would explain why it started to move faster when the sun came up.

Any other ideas, theories, hypotheses?

Alpha Pavonis

Posted: Tue Mar 22, 2005 9:28 am
by Boldra
I checked the photometry data for Alpha Pavonis (http://nightskylive.net/sd/sd050319/HD193924.html), and the first measurement is at 17:52, at 36°. This strongly suggests my ID is correct!

Boldra