Moravian instruments, Inc., source: https://www.gxccd.com/art?id=317&lang=409, printed: 30.04.2025 22:19:52

Main page▹Observations

15.1.2007
2003UB313—the 10th planet or only the biggest known KBO?
 At 97 AU from the Sun and about 3000 km diameter, the Kuiper-belt object 2003UB313 gleamed only at 18.9m on January, 2006. Although slightly bigger than Pluto, this object appears about 100× dimmer. Still amateur astronomers can capture it with backyard telescope and CCD camera.

No matter if the 2003UB313 KBO should be called the 10th planet, because it is bigger than Pluto, or Pluto should be no longer called a planet, because the 2003UB313 KBO is bigger than it, imaging the object of 18.9m, relatively close to horizon, can be a challenging task for amateur astronomer. Imaging the Pluto with its 14m brightness is an easy task these days—modern CCD camera can record its light within seconds even on small 6 inch telescope. But capturing of almost 19m object with backyard telescope would be considered impossible only ten years ago.

Kamil Hornoch used his 35 cm (approx. 13.8 inch), f/4.7 Newtonian reflector and G2CCD-0400 camera to image the 10th planet during three nights on January, 2006.

January 27th, 2006, exposure 15.5 min, binning 2 × 2, no filter

January 27th, 2006, exposure 15.5 min, binning 2 × 2, no filter

January 28th, 2006, exposure 17 min, binning 2 × 2, no filter

January 28th, 2006, exposure 17 min, binning 2 × 2, no filter

January 29th, 2006, exposure 16.5 min, binning 2 × 2, no filter

January 29th, 2006, exposure 16.5 min, binning 2 × 2, no filter

Notice the 2003UB313 disappeared on the image from January 28th, 2006—the KBO virtually merged with the background star.

The same DSS-2 (Digitized Sky Survey - 2) field is displayed below for reference.

The DSS-2 red-light image of the same field

The DSS-2 red-light image of the same field

Both successful 2003UB313 observations were sent to MPC. Positional measurement error was only a few tenths of arc second, which quite satisfactory for a backyard telescope.

   Date (UT)           R.A.         Decl.      Residuals ["]
2006 01 27.77979   01 35 16.75   -05 32 33.3    0.1-  0.3+
2006 01 29.77124   01 35 17.94   -05 32 04.1    0.3+  0.4-

Epoch 2006 Mar. 6.0 TT = JDT 2453800.5                  MPC
M 197.63680              (2000.0)            P               Q
n   0.00177056     Peri.  151.42911     -0.91261338     -0.01855121             T = 2545502.32333 JDT
a  67.6700187      Node    35.86957     -0.34975394     -0.48181998             q =    37.7767188
e   0.4417510      Incl.   44.18694     +0.21168139     -0.87607383
P 557              H   -1.2           G   0.15           U   3
From 186 observations at 14 oppositions, 1954-2006, mean residual 0".44.

Images from G2CCD-0400 captured and processed by Kamil Hornoch.

The Digitized Sky Survey was produced at the Space Telescope Science Institute under U.S. Government grant NAG W-2166. The images of these surveys are based on photographic data obtained using the Oschin Schmidt Telescope on Palomar Mountain and the UK Schmidt Telescope. Acknowledgments.