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Lester
10-03-2012, 05:21 PM
Hi all, just did a plot of Comet Lovejoy's path for the next 2 days to see if it is passing by any interesting objects. It will pass near SAO 150223 Star magnitude 4.45 . Nothing strange about that, But The Sky 6 was showing what looked like 4 diffraction spikes comming out from the star. So I zoomed in and found 4 rows of faint stars in perfect alignment. Not just 2 or 3 or 4 stars, but 7 to the north, 14 to the south, 12 to the west and 12 to the East. They range from magnitude 13.8 to 15.8 .

Here is info on SAO 150223, copied from The Sky 6

Object name: SAO 150223
Other ID: HIP 24244
Magnitude: 4.45
Equatorial: RA: 05h 12m 52.956s Dec: -1151'31.948"(current)
Equatorial 2000: RA: 05h 12m 17.902s Dec: -1152'09.188"
Horizon: Azim: 8508'41.617" Alt: +2759'12.976"
Alternate names: HIP 24244 GSC 5338:1445 PPM 215426
Visibility: Rise 13:51, Set 03:05
Transit time: 20:26
Flamsteed-Bayer: 3-Iota Leporis
Name 6: HD 33802
Name 7: B-12 1095
Object type: Star
Spectral: B8V
Source catalog: Hipparcos Catalog
Sun distance (au): 15245020
Hour angle: -04h 15m 34.326s
Air mass: 2.13
Magnitude B: 4.34
Magnitude V: 4.45
Screen x,y: 638.00, 320.00
Parallax: 13.5300
Proper Motion: 24.95, -31.22
Position error: 0.5500, 0.4400
Sidereal time: 00:57
Click distance: 2.0000
Light years: 241.06
Parsecs: 73.9098
Catalog number: 150223
Celestial type: 0
Julian date: 2455996.6946
Angular separation: 0002'52.685"


I will be keen to hear if anyone can shed some light on this massive alignment. Will be imaging this area tomorrow night if clear in search of the comet and to see if this alignment is really there.

All the best.:thumbsup:

Octane
10-03-2012, 05:50 PM
Haha, wow! I see what you mean.

What's even stranger is that they're in perfect alignment with the RA/DEC lines.

That is very, very cool!

H

Octane
10-03-2012, 05:54 PM
Screenshot included for great justice.

H

thunderchildobs
10-03-2012, 06:06 PM
The "stars" are the results of diffraction spikes being scanning from the orginal photo plates.

If you look at almost any bright star you will see the same effect.

Brendan

PeterM
10-03-2012, 06:08 PM
Tom Bisque explains this.
Peter M.

"The pattern is caused by the diffraction spikes of the telescope used to create the data.

http://www.bisque.com/tom/catalog/catalog.asp


"Specifically the link GSC diffraction Spikes shows an example of this. However the GSC data is not the only stellar catalog with this issue. Even the NOMAD dataset used with TheSkyX is prone to this but in that case there is a flag used to indicate when the data is in fact not valid but rather caused by the telescope's diffraction spikes which hold the secondary optics."

DSS image (60x60 arc min) attached.
PS also look for the non real stars that form the outer halo in a screenshot from SkyX.

Octane
10-03-2012, 06:22 PM
That makes perfect sense.

Thanks for the clarification, guys. :)

H

Lester
10-03-2012, 07:22 PM
Thanks for the explanaition Peter and Brendan. Also Humayun.

All the best.

Kal
11-03-2012, 07:00 PM
Nice spot Lester and interesting explanation Peter