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Ton 490 is a quasar of magnitude 15.4 (slightly variable).
It has a redshift (z) of 1.631, which equates to a distance of around 8,000 million light years.
This means that its light has been travelling for about twice as long as the earth has existed.
Though it appears as a faint star it is really one of the brightest objects in the universe!
Imaged using an 8" newtonian at f/8 (prime focus) by a Cookbook 245 CCD camera, (30 images @ 45 sec stacked.)
The image was measured using AIP4win, referenced to the USNO-A2.0 catalouge.
The results are as follows:
Target object(s):TON490
Astrometric Image: ton490.fts
UT date of obs, YYYY MM DD: 2001 03 15
UT time of obs, HH MM SS: 05 43 55
Telescope focal length: 1662.676 mm
X size of pixel (mm): 0.0085
Y size of pixel (mm): 0.0085
Ref star data source: USNO-A2.0 disk 11
TARGET OBJECT(S)
X Y mag RAS DEC S
object name pixels pixels CCD hh mm ss.sss +dd mm ss.ss Y
1 ton490 390.837 365.875 15.98 10 13 53.627 +24 49 18.72 Y
2 starD 373.747 419.231 13.81 10 13 54.735 +24 48 21.78 Y
3 starC 342.969 237.134 12.84 10 13 57.842 +24 51 31.06 Y
4 StarB 325.544 289.097 12.01 10 13 58.981 +24 50 35.60 Y
ASTROMETRIC RESIDUALS
RArms DECrms
(arcsec) (arcsec)
001.351 000.689
REFERENCE STARS Catalog epoch: 2000
RAS DEC Mu(RA) Mu(DC) mag X Y S
# hh mm ss.sss +dd mm ss.ss -- arcsec/yr cat pixels pixels Y
1 10 13 35.070 +24 55 18.60 00.000 00.000 15.40 643.731 036.220 Y
2 10 13 33.510 +24 51 57.30 00.000 00.000 13.80 654.108 227.882 Y
3 10 13 43.000 +24 51 35.70 00.000 00.000 15.20 530.869 241.606 Y
4 10 13 39.710 +24 46 58.90 00.000 00.000 16.90 559.252 506.623 Y
5 10 13 58.720 +24 46 27.80 00.000 00.000 15.50 314.539 522.048 Y
6 10 14 17.740 +24 47 35.40 00.000 00.000 16.20 074.085 445.163 Y
7 10 14 17.030 +24 48 44.50 00.000 00.000 16.10 087.185 379.819 Y
8 10 14 10.380 +24 51 19.00 00.000 00.000 13.40 180.056 237.853 Y
9 10 14 17.220 +24 52 52.90 00.000 00.000 14.90 096.028 145.459 Y
10 10 14 23.040 +24 53 43.10 00.000 00.000 15.30 024.409 093.985 Y
11 10 14 01.120 +24 54 01.70 00.000 00.000 15.10 307.455 090.713 Y
12 10 13 31.940 +24 50 05.50 00.000 00.000 19.10 672.727 333.094 Y
13 10 13 40.700 +24 54 44.50 00.000 00.000 17.20 570.048 064.644 Y
PHOTOMETRY Photometric zero point: 22.85
Plate center, RAS: 10 13 54.959
Plate center, DEC: +24 50 47.02
X of plate center: 378.00
Y of plate center: 281.00
PA, image +Y axis: 2.97