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Date and Time of the Query: 2019-04-25 T23:14:05 PDT
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Diameter data point(s) for object NGC 7018

Diameter Data --- Published and Homogenized (arcsec) Units

  Published UnitsHomogenized Units
No.Observed Passband
REFCODE
Major Axis
(2a)
Major Axis UnitsMinor Axis
(2b)
Minor Axis UnitsAxis Ratio (b/a)Major Axis Unc.Ellipticity
(1 - b/a)
Eccentricity
[(a/b)2-1]/
[(a/b)2+1]
Position Angle
(deg)
[published]
Reference LevelFrequency (Hz)Major Axis
(2a)
(arcsec)
Major Axis Unc.Axis Ratio (b/a)Ellipticity
(1 - b/a)
Eccentricity
[(a/b)2-1]/
[(a/b)2+1]
cos-1(b/a)
(deg)
Position Angle
(deg)
[J2000]
1 POSS1 103a-O
1968MCG4..C...0000V
0.40 arcmin 0.30 arcmin ... ... ... ... ... Very high surface brightness 7.40E+14 24.00 ... 0.75 0.25 0.28 41 ...
2 POSS1 103a-O
1968MCG4..C...0000V
0.80 arcmin 0.50 arcmin ... ... ... ... ... Very low surface brightness 7.40E+14 48.00 ... 0.62 0.38 0.44 51 ...
3 ESO-Uppsala "Quick Blue" IIa-O
1982ESOU..C...0000L
0.90 arcmin 0.60 arcmin ... ... ... ... 86
[B1950]
About 25.5 B-mag arcsec^-2^ 6.81E+14 54.00 ... 0.67 0.33 0.38 48 86
[J2000]


Detailed Information for Each Entry

 No. 1
                                Published Units:                    Homogenized Units:

Reference Code                : 1968MCG4..C...0000V
Published Object Name         : MCG -04-49-015                
Frequency Targeted            : POSS1 103a-O                  
Major Axis (2a)               : 0.40       arcmin                   2a = 24.00 arcsec
Uncertainty                   : ...                                 ... 
Minor Axis (2b)               : 2b =  0.30      arcmin              2b = 18.00 arcsec 
Uncertainty                   : ...                                 ...
Axis Ratio                    : ...                                 b/a = 0.75
Uncertainty                   : ...                                 ...
Ellipticity                   : ...                                 1 - b/a = 0.25
Uncertainty                   : ...                                 ...
Eccentricity                  : ...                                 [(a/b)2-1]/[(a/b)2+1] = 0.28
Uncertainty                   : ...                                 ...
Cos-1(b/a)                    : ...                                 41 deg
Position Angle [Equinox]      : ...                                 ...
Uncertainty                   : ...                                 ...
Significance                  : No uncertainty reported
Diameter Reference Level      : Very high surface brightness  
Frequency                     : 4050         A                      7.40E+14 Hz
Frequency Mode                : Broad-band detector (e.g. photographic plate)

Measurement Mode               
    Detector Type             : Photographic plate, print, or film
    Fitting Technique         : Eye estimate
    Measured Quantity         : "Inner" diameter
Coordinates Targeted          : 210436          -2540    (B1950)
Qualifiers                    : From new, raw data
NED Comment                   :                                         

No. 2 Published Units: Homogenized Units: Reference Code : 1968MCG4..C...0000V Published Object Name : MCG -04-49-015 Frequency Targeted : POSS1 103a-O Major Axis (2a) : 0.80 arcmin 2a = 48.00 arcsec Uncertainty : ... ... Minor Axis (2b) : 2b = 0.50 arcmin 2b = 30.00 arcsec Uncertainty : ... ... Axis Ratio : ... b/a = 0.62 Uncertainty : ... ... Ellipticity : ... 1 - b/a = 0.38 Uncertainty : ... ... Eccentricity : ... [(a/b)2-1]/[(a/b)2+1] = 0.44 Uncertainty : ... ... Cos-1(b/a) : ... 51 deg Position Angle [Equinox] : ... ... Uncertainty : ... ... Significance : No uncertainty reported Diameter Reference Level : Very low surface brightness Frequency : 4050 A 7.40E+14 Hz Frequency Mode : Broad-band detector (e.g. photographic plate) Measurement Mode Detector Type : Photographic plate, print, or film Fitting Technique : Eye estimate Measured Quantity : "Outer" diameter Coordinates Targeted : 210436 -2540 (B1950) Qualifiers : From new, raw data NED Comment :
No. 3 Published Units: Homogenized Units: Reference Code : 1982ESOU..C...0000L Published Object Name : ESO 529-IG 027 Frequency Targeted : ESO-Uppsala "Quick Blue" IIa-O Major Axis (2a) : 0.90 arcmin 2a = 54.00 arcsec Uncertainty : ... ... Minor Axis (2b) : 2b = 0.60 arcmin 2b = 36.00 arcsec Uncertainty : ... ... Axis Ratio : ... b/a = 0.67 Uncertainty : ... ... Ellipticity : ... 1 - b/a = 0.33 Uncertainty : ... ... Eccentricity : ... [(a/b)2-1]/[(a/b)2+1] = 0.38 Uncertainty : ... ... Cos-1(b/a) : ... 48 deg Position Angle [Equinox] : 86 deg [B1950] 86 deg [J2000] Uncertainty : ... ... Significance : No uncertainty reported Diameter Reference Level : About 25.5 B-mag arcsec^-2^ Frequency : 4400 A 6.81E+14 Hz Frequency Mode : Broad-band detector (e.g. photographic plate) Measurement Mode Detector Type : Photographic plate, print, or film Fitting Technique : Eye estimate Measured Quantity : "Outer" diameter Coordinates Targeted : 210430. -253754. (B1950) Qualifiers : From new, raw data NED Comment : Diameters and PA flagged uncertain.

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