Friday, April 06, 2018

reviewed ES 2603

Did a deeper dive into ES 2603 extracting the current values from the Washington Double Star database.

pair PA sep
AB 256 6.1
AC 359 11.1
AD 131 16.1
AE 306 18
AF 320 36.2
AG 261 60.3
AH 256 57
AI 279 69.6
AL 71 98.3
AN 206 116.1
AO 78 138.9
AQ 325 45.6
AS 262 20.3
AT 196 27.5
AU 213 35.3

Oh. More stars. Not entirely surprised by that.

But no K; that's weird. There clearly is a pair at the L location. (At least, it is not listed with HS 2603.]

Or J. But that might be correct in that I don't see anything at the J location in SkyTools 3 Pro.

members of multi-star system ES 2603 plotted

Generated a plot of the positions and separations with my latest generation spreadsheet.

The positions of B, C, E, F, H, I, L, N, and O look pretty good.

D is markedly different. WDS says this is close to A, to the south-east, at mag 14.1 as opposed to what SkyTools shows, with D near O. This faint star is visible in the image!

ST3P did not list a G star; WDS shows it near H. Ah ha, the tight pair in the photo. G is brighter at 9.6 and slightly further from A at 60.3" while H is mag 10.5 and 57.0". G is at an angle of 261 vs. 256 putting it north of H. This all checks out.

The WDS includes Q. It says this is north of F at mag 13.2. F is 11.7. This checks out too.

The S star is purportedly a mag 14.1 star beyond B. I think I have captured this in my image! Just barely visible.

The T and U elements from the WDS I do not see in the BGO photo. They are south-south-west of A. The USNO database says they are magnitude 15 stars. Ah. That's why.

While checking the double star database, I looked up the magnitude value for B. Oh, it's listed at 12.9. There you go. Rather dim. Which matches what I am seeing in the photo.

BGO image of ES 2603 annotated

So, I think I have tagged all of the stars from the WDS save the extremely dim ones...

There is more data offered in the WDS but I did not review or cross-check these.

Ea 291 0.1
EB 146 14.2
EC 86 14.7
EF 334 18.6
EG 246 49
EH 240 47.1
EI 271 54


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