20312+0513 AG  257

 
 
20h 31m 13.51s +05 13' 08.7" P.A. 75 sep 1.6 mag 9.49,9.77 Sp K0 dist. 48.54 pc (158.34 l.y.)
 
 
Coord 2000
20312+0513
Discov num
AG  257
Comp
Coord arcsec 2000
20 31 13.51 +05 13 08.7
Date first
1902
Date last
2016
Obs
45
Pa first
55
Pa last
75
P.A. Now (θ)
75°
Sep first
1.6
Sep last
1.7
Sep. Now (ρ)
1.6"
Mag pri
9.49
Mag sec
9.77
delta mag (ΔM)
0.28
Spectral class
K0 (yellow-orange)
Pri motion ra
+303
Sec motion ra
+303
Pri motion dec
+275
Sec motion dec
+275
Notes
N O (See Notes, Orbital solution)
This double is physical.
 
 
OTHER CATALOGS AND DESIGNATIONS
 
 
Precise pa
75
Precise sep
1.687
Constellation
Delphinus
HIP
101236
Tycho2
0518-01755-1
Gaia DR2
76226458752
HD
195434
BD
BD+04 4470
Distance
48.54
Distance ly
158.34
last precise pa
75
last precise sep
1.687
 
 
ORBITAL ELEMENTS
 
 
Period (P)1996.6y± 170.5 Periastron (T)1945.9y± 130.3 Semi-major axis (a)3.763a± 0.156
Eccentricity (e)0.493± 0.051 Inclination (i)74.2°± 8.4 Longitude of periastron (ω)± 7.4
Node (Ω)61.2°± 8 Note Grade5(1=Definitive, 9=Indet.)
Equinox2000 Last observation
label rho theta
2000 1.729 70.8
2001 1.723 71.0
2002 1.716 71.2
2003 1.710 71.4
2004 1.703 71.6
2005 1.697 71.8
2006 1.690 72.1
2007 1.683 72.3
2008 1.676 72.5
2009 1.669 72.7
2010 1.662 72.9
2011 1.655 73.1
2012 1.648 73.4
2013 1.640 73.6
2014 1.633 73.8
2015 1.626 74.0
2016 1.618 74.3
2017 1.611 74.5
2018 1.603 74.7
2019 1.595 75.0
2020 1.587 75.2
2021 1.580 75.5
2022 1.572 75.7
2023 1.564 75.9
2024 1.556 76.2
2025 1.548 76.4
2026 1.539 76.7
2027 1.531 77.0
2028 1.523 77.2
2029 1.515 77.5
2030 1.506 77.7

Note: Theta is PA, Rho is Sep. For yearly orbits, data refer to Jan 1st.
 
grafico orbita






wds20312%2B0513a.png orbit plot
Measures: green=micrometric, blue=interferometric, purple=photographic
 
 
 
WDS HISTORIC DATA
 
 
coord_2000 discov_num comp epoch obs pa sep mag_pri mag_sec spectr notes coord_arcsec_2000
20312+0513 AG 257 1999 36 70 1.7 9.49 9.77 K0 D 203113.51+051308.7
20312+0513 AG 257 2008 37 73 1.7 9.49 9.77 K0 D 203113.51+051308.7
20312+0513 AG 257 2009 44 73 1.7 9.49 9.77 K0 D 203113.51+051308.7
20312+0513 AG 257 2015 42 75 1.7 9.49 9.77 K0 NO 203113.51+051308.7
20312+0513 AG 257 2016 43 75 1.7 9.49 9.77 K0 NO 203113.51+051308.7

If you need more information about this double, apply for a data request form to the WDS.