Search found 78 matches
- Fri Mar 18, 2005 6:39 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Wise Observatory (WO) CONCAM status
- Replies: 9
- Views: 8156
WO CONCAM
I am sorry not have seen your message earlier. The light glow to the East is man-made; the town of Mizpe Ramon, five km East of the observatory, has quite strong lights in comparison to the size of its population (5000 people). The lights are mostly sodium, some low-pressure and some high-pressure. ...
- Tue Mar 08, 2005 4:59 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Algol Minimum
- Replies: 0
- Views: 2877
Algol Minimum
Sky and Telescope has the following news item: ------------------------------------------------------------- ALGOL IN ECLIPSE Also on the evening of March 10th, the bright eclipsing variable star Algol dips into eclipse for a few hours centered on 10:22 p.m. Eastern Standard Time: SkyandTelescope.co...
- Tue Mar 08, 2005 4:49 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Heat the lens
- Replies: 12
- Views: 14340
Re: No Dew Inside This Dome. Outside, Yes.
I'm only mildly acquainted with your setup, but for our Sentinel Fireball Network, we use the equipment I show on my web site at <http://home.earthlink.net/~mtnv95959a/meteor_beginnings.html>. A resistor and thermostat is inside the cylinder below the dome area. We never have dew problems on the in...
- Fri Feb 04, 2005 9:09 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: A color concam?
- Replies: 7
- Views: 7768
Color images
I don't know of a way to disentangle the numerical charge value for each color when using a color CCD. In essence, what you write is correct, it is the extraction that is problematic. I also think that the individual color pixels (three for each 'real' pixel) have less charge depth than regular pixe...
- Mon Jan 31, 2005 4:56 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: A color concam?
- Replies: 7
- Views: 7768
COlor CONCAMs
Color images are nice but have small scientific value. It would be infinitely better to make three simultaneous B&W images through different color filters, combine them into a "real color" image, but extract the three different magnitudes of the objects separately. This, however, requi...
- Mon Jan 31, 2005 4:52 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Policy on saving NSL data
- Replies: 10
- Views: 12140
Storage
I suggest NOT going SCSI, but using the cheaper alternative. We are regularly using 200GB ATA disks and are pretty happy. Note though that we are doubling the data up on two disks, so that a crash does not destroy irreplaceable observation data.
Noah Brosch
Noah Brosch
- Tue Jan 11, 2005 4:50 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Finding Comet Machholz
- Replies: 5
- Views: 7080
Comet Machholtz
Tilvi, as you seem to have found the comet, which is getting brighter, it might be interesting to see whether you could produce a brightness diagram by collecting "calibrated" magnitudes, relative to other stars in the field, and for all times using all the CONCAMS that see the comet. This...
- Sat Jan 01, 2005 7:00 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Finding Comet Machholz
- Replies: 5
- Views: 7080
Machholtz
Bob, perhaps if Lior could add this as a WOLF feature, the labels could include the comet as well.
- Tue Dec 21, 2004 7:21 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Polaris variability
- Replies: 24
- Views: 16008
Polaris variability
Lior, I am not sure what are you trying to do. The new plots show the magnitude difference (count ratio) of Polaris to two ther bright northern stars. I am (almost) sure that many of the readers do not understand the EXCEL tables and the plots. In order to show definitiely that you detected and meas...
- Fri Dec 10, 2004 5:54 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Polaris variability
- Replies: 24
- Views: 16008
Polaris variability
Lior: I suggest very strongly to use the following procedure: a. Start using Julian days and fraction of days for timing the exposures b. Select the mid-time of observation to assign atime to a magnitude c. Perform the same type of reductions to all Northern Hemisphere CONCAMs d. Perform the same ty...
- Mon Dec 06, 2004 4:54 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Placing CONCAM1s near CONCAM3s for meteor studies
- Replies: 8
- Views: 5810
CONCAM1 for meteors
Noah, One question -- can these CONCAM1s be fit with a light chopper? - RJN That was the project I entrusted the student with. I'll give here a short description of the thoughts, but first the problems: 1. The camera does not have a shutter thus there is no way to obtain a dark. 2. Any shutter that...
- Mon Dec 06, 2004 9:36 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Geminids 2004
- Replies: 0
- Views: 2618
Geminids 2004
The Geminid meteor shower will be visible next week. This shower originates from the asteroid (possibly extinct comet) 3200 Phaeton. Sky & Telescope have a special item on this year's Geminids at http://skyandtelescope.com/observing/objects/meteors/article_802_1.asp. The gist is that the meteors...
- Sun Dec 05, 2004 5:07 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Placing CONCAM1s near CONCAM3s for meteor studies
- Replies: 8
- Views: 5810
Two CONCAMs
We have, as you remember, one CONCAM-1 that we have not yet put into operation. I could check whether it would be possible to mount it on top of our site manager's house in the town of Mizpe Ramon. The location is about five km away from the WiseObs, near the edge of the town and at a higher elevati...
- Sun Dec 05, 2004 4:09 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Polaris variability
- Replies: 24
- Views: 16008
True nature of Polaris
Lior, you might also want to look at the paper by Evans et al. (2002, ApJ 567, 1121) that discusses Polaris from an astrophysically evolutionary point of view and combines optical with data at other wavelengths.
Cheers,
Noah Brosch
Cheers,
Noah Brosch
- Sat Dec 04, 2004 3:35 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Polaris variability
- Replies: 24
- Views: 16008
Re: Polaris variability
These files show that Polaris changes its brightness over four days. After two days the brightness of Polaris is reduced by about about 2 percents, and two days after it is increased back by the approximately the same percentage. http://nightskylive.net/temp/alpumi.xls http://nightskylive.net/temp/...
- Fri Dec 03, 2004 8:48 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Turn-key auroral imagers
- Replies: 1
- Views: 3750
NSL cameras vs. auroral imagers
Bob, the auroral imagers are designed to image spectral features. The aurora shows up in forbidden emission lines and the cameras used for imaging it must have narrow-band filters. They also use intensified video cameras, because sometimes there are fast variations in the brightness, color. or posit...
- Wed Dec 01, 2004 4:02 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: plot of polaris (C5-B) night average from 6/3/04 to 11/3/04
- Replies: 2
- Views: 3292
Photometry with NSL hardware
Actutally, one should not try to re-discover astronomy but learn from almost a century of experience doing stellar photometry. What Lior's plot shows is probably clouds. In order to obtain absolute photometry, one compares unknown stars with standard stars. A few stars are standards, and the primary...
- Thu Nov 25, 2004 5:56 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Leonids 2004
- Replies: 9
- Views: 15496
Leonids
Note that all the CONCAM Leonids posted above are from the "classical" peak. The extra peak predicted for the 13th did not materialize.
Noah Brosch
Noah Brosch
- Tue Nov 16, 2004 5:56 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: What's Up in October and November
- Replies: 4
- Views: 6690
Meteors
This year's Leonids are predicted to be weak, with a low ZHR. The "best" shower in 2004 will probably be the Geminids. The peak is December 13, 22h 20m UT with a ZHR of 120. Locations in the Northern Hemisphere are preferred, because the radiant is visible all night long (culminates at 02 ...
- Mon Nov 01, 2004 5:57 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Meteor trajectory
- Replies: 11
- Views: 9621
Finding meteorites
Tilvi, it is very unlikely that the present CONCAMs will locate a meteorite. The main reason is that the only pair now in operation is in Hawaii, where a fall would most likely end up in the ocean. The Australians are putting up a camera network in their desert, where meteorites will stay on land, a...
- Mon Nov 01, 2004 5:34 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Meteor trajectory
- Replies: 11
- Views: 9621
Meteor physics
Bob, thanks for your comments. As usual, nature is perverse in complicating things. Essentially, there are two kinds of meteors (or models of meteors). One assumes that the meteoroid (the incoming body) is a single entity, what would normally be called "a piece of rock". The other, that is...
- Sat Oct 30, 2004 8:34 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Meteor trajectory
- Replies: 11
- Views: 9621
Meteors
Lior, the European network uses film cameras, and large format negatives, for their fisheye images. These have many more pixels than any CCD camera has. The pixels are extremely fine, perhaps a micron or so in size. This determines the astrometric accuracy. Regarding the method, perhaps this Nature ...
- Sat Oct 30, 2004 9:06 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Meteor trajectory
- Replies: 11
- Views: 9621
Meteors
And here is another link where a more detailed description of the network is given: http://www.molau.de/meteore/imc97-2.html. Note that the potential of on-line detection, measurement, and trajectory calculation has not been realized yet.
Noah Brosch
Noah Brosch
- Sat Oct 30, 2004 9:00 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Meteor trajectory
- Replies: 11
- Views: 9621
Meteor trajectory
Here is a link where the kind of data that can be derived from proper two-station meteor observations is described:
http://www.asu.cas.cz/english/new/EN060402.html
Noah Brosch
http://www.asu.cas.cz/english/new/EN060402.html
Noah Brosch
- Sat Oct 30, 2004 7:57 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Meteor trajectory
- Replies: 11
- Views: 9621
Meteor trajectory
Lior, this derivation is very nice. It is true that 3D trackes of meteors are analyzed elsewhere, but these are taken by an instrument with the potential of accurate photometry. Thus from your derivation it may be possible to associate the light production by the meteor with a specific path trough t...