VLA calibrator information for 1221+2813

This page summarizes the information for 1221+2813 as found in the original VLA calibrator list and, if found there, a link to search the NRAO VLA Archive Survey (NVAS) for calibrator data before 2010. Furthermore, a table with the most recent approximate flux densities, starting from 2017 as mined from the VLA CASA pipeline is presented.

If shown at the top, we have recovered the original, pre-WIDAR ANTSOL flux density solutions from the period roughly 2000-2007; symbols as explained next.
The mined data are plotted (gray, on the left hand side) as function of (log) frequency on the top and as function of time on the bottom. The frequency band symbols in the bottom panel follow the symbols as outlined in the top panel:

4-band  (~75 MHz) horizontal stripe       X-band (~10.0 GHz) cross
P-band (~350 MHz) open triangle        U/Ku-band (~15.0 GHz) filled square
L-band (~1.5 GHz) VLA-Y shape             K-band (~22.2 GHz) open circle
S-band (~3.0 GHz) filled triangle      A/Ka-band (~33.2 GHz) 6-pointed star
C-band (~6.0 GHz) open square             Q-band (~45.0 GHz) filled circle
Assume a 10% flux density error on each point, up to 30% for the higher frequency data points. The dashed lines in the frequency plot indicate the approximate spectral index in the frequency band (tied to the measured flux density).
Depending on the spectral behavior, different receiver observing bands (as indicated with the log-frequency axis) may have very different typical flux densities. Note that there can be significant flux density changes for different array configurations, which start date is indicated at the top of the time-line figure. Calendar years are separated by vertical dotted lines.
If shown, a curve depicts a fit to the (unweighted) average data for each band (if there are more than two bands with measured flux densities). The fit equation is listed at the top where the x-coordinate represents the base-10 log of the frequency (GHz) and the y-coordinate represents the base-10 log of the flux density (mJy/bm). The fit may use more data than shown and is using data with different time stamps, which means typically different flux densitities in a single band for genuine variable sources (and/or observed in different array configurations).
Depending on the variability of the source, array configuration and the quality of the data, this fit may, or may not, be representative for the data!

(Click on the figure for a larger view in a new tab/window)

 Original (outdated) VLA calibrator list information: 
 IAU NAME EQUINOX  PC RA(hh,mm,ss)    DEC(ddd,mm,ss)   POS.REF ALT.NAME
 ===================================================================
 1221+282   J2000  A 12h21m31.690515s  28d13'58.500260"  Aug01         
 1219+285   B1950  A 12h19m01.115600s  28d30'36.526000"
 -----------------------------------------------------
 BAND        A B C D    FLUX(Jy)    UVMIN(kL)  UVMAX(kL)
 =====================================================
  20cm    L  P P P P       0.86
   6cm    C  P P P P       0.90
 3.7cm    X  P P P P       0.88
   2cm    U  S S S S       0.7
 0.7cm    Q  W W W W       0.6

Default NVAS search around this position (in new tab/window)

Results from CASA pipeline flux density mining:
Observing date (UT)Flux density (Jy/bm)Source name used
L-band data ("VLA Y-arm" symbols)
201707040.689J1221+2813
201707100.682J1221+2813
201707160.698J1221+2813
201707160.701J1221+2813
201708150.682J1221+2813
201708250.684J1221+2813
201803200.622J1221+2813
201902190.700J1221+2813
201903020.684J1221+2813
201903040.670J1221+2813
201903110.682J1221+2813
201903130.699J1221+2813
201903290.717J1221+2813
201904030.710J1221+2813
201904100.715J1221+2813
201904150.714J1221+2813
201904160.728J1221+2813
201904230.740J1221+2813
201908100.732J1221+2813
201908100.728J1221+2813
201908110.733J1221+2813
201908210.733J1221+2813
201908220.729J1221+2813
201908220.726J1221+2813
201908250.723J1221+2813
201908280.733J1221+2813
201909060.702J1221+2813
201909060.703J1221+2813
201909060.703J1221+2813
201909080.708J1221+2813
201909174.336J1221+2813
201909260.755J1221+2813
202208100.723J1221+2813
S-band data (filled triangles)
202206200.647J1221+2813
C-band data (open squares)
201712280.546J1221+2813
201801050.549J1221+2813
201901100.637J1221+2813
201908030.670J1221+2813
201910080.656J1221+2813
202206140.558J1221+2813
X-band data (X-crosses)
201908030.649J1221+2813
201908030.649J1221+2813
201908230.622J1221+2813
202005120.483J1221+2813
202104240.544J1221+2813
202205240.446J1221+2813
202207230.507J1221+2813
U-band data (filled squares)
201804100.643J1221+2813