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Date and Time of the Query: 2019-02-19 T18:10:44 PST
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Diameter data point(s) for object NGC 6491

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
1973UGC...C...0000N
1.30 arcmin 0.50 arcmin ... ... ... ... 39
[B1950]
About 25.0 B-mag arcsec^-2^ 7.40E+14 78.00 ... 0.39 0.61 0.74 67 38
[J2000]
2 K_s (2MASS isophotal)
20032MASX.C.......:
19.1 (a) arcsec ... ... 0.740 (b/a) ... ... ... 35
[J2000]
20.0 K-mag arcsec^-2^ 1.38E+14 38.20 ... 0.74 0.26 0.29 42 35
[J2000]
3 K_s (2MASS "total")
20032MASX.C.......:
31.4 (a) arcsec ... ... 0.740 (b/a) ... ... ... 35
[J2000]
Diameter for "total" magnitude 1.38E+14 62.80 ... 0.74 0.26 0.29 42 35
[J2000]
4 POSS1 103a-O
1962MCG1..C...0000V
0.40 arcmin 0.30 arcmin ... ... ... ... ... High surface brightness 7.40E+14 24.00 ... 0.75 0.25 0.28 41 ...
5 POSS1 103a-O
1962MCG1..C...0000V
1.20 arcmin 0.50 arcmin ... ... ... ... ... Very low surface brightness 7.40E+14 72.00 ... 0.42 0.58 0.70 65 ...
6 RC3 D_25, R_25 (blue)
1991RC3.9.C...0000d
1.09 log(2a) + 1 ... ... 0.38
log(a/b)
0.06 ... ... 39
[J2000]
25.0 B-mag arcsec^-2^ 6.81E+14 73.80 10.90 0.42 0.58 0.70 65 38
[J2000]
7 RC3 D_0 (blue)
1991RC3.9.C...0000d
1.11 log(2a) + 1 ... ... ... ... ... ... ... 25.0 B-mag arcsec^-2^ 6.81E+14 77.30 ... ... ... ... ... ...


Detailed Information for Each Entry

 No. 1
                                Published Units:                    Homogenized Units:

Reference Code                : 1973UGC...C...0000N
Published Object Name         : UGC 11008                     
Frequency Targeted            : POSS1 103a-O                  
Major Axis (2a)               : 1.30       arcmin                   2a = 78.00 arcsec
Uncertainty                   : ...                                 ... 
Minor Axis (2b)               : 2b =  0.50      arcmin              2b = 30.00 arcsec 
Uncertainty                   : ...                                 ...
Axis Ratio                    : ...                                 b/a = 0.39
Uncertainty                   : ...                                 ...
Ellipticity                   : ...                                 1 - b/a = 0.61
Uncertainty                   : ...                                 ...
Eccentricity                  : ...                                 [(a/b)2-1]/[(a/b)2+1] = 0.74
Uncertainty                   : ...                                 ...
Cos-1(b/a)                    : ...                                 67 deg
Position Angle [Equinox]      :  39    deg [B1950]                  38 deg [J2000]
Uncertainty                   : ...                                 ...
Significance                  : No uncertainty reported
Diameter Reference Level      : About 25.0 B-mag arcsec^-2^   
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          : 174930.         +613200.    (B1950)
Qualifiers                    : From new, raw data
NED Comment                   :                                         

No. 2 Published Units: Homogenized Units: Reference Code : 20032MASX.C.......: Published Object Name : 2MASX J17500071+6131542 Frequency Targeted : K_s (2MASS isophotal) Major Axis (2a) : a = 19.1 arcsec 2a = 38.20 arcsec Uncertainty : ... ... Minor Axis (2b) : ... 2b = 28.27 arcsec Uncertainty : ... ... Axis Ratio : b/a = 0.740 b/a = 0.74 Uncertainty : ... ... Ellipticity : ... 1 - b/a = 0.26 Uncertainty : ... ... Eccentricity : ... [(a/b)2-1]/[(a/b)2+1] = 0.29 Uncertainty : ... ... Cos-1(b/a) : ... 42 deg Position Angle [Equinox] : 35 deg [J2000] 35 deg [J2000] Uncertainty : ... ... Significance : No uncertainty reported Diameter Reference Level : 20.0 K-mag arcsec^-2^ Frequency : 2.17 microns 1.38E+14 Hz Frequency Mode : Broad-band detector (e.g. photographic plate) Measurement Mode Detector Type : Maps (e.g., 2MASS, VLA, Sloan) Fitting Technique : Ellipse fitting to image Measured Quantity : Isophotal diameter Qualifiers : A radius is given in DIA_MAJ, not a diameter Coordinates Targeted : 267.502930 61.531769 (J2000) Qualifiers : From new, raw data NED Comment :
No. 3 Published Units: Homogenized Units: Reference Code : 20032MASX.C.......: Published Object Name : 2MASX J17500071+6131542 Frequency Targeted : K_s (2MASS "total") Major Axis (2a) : a = 31.4 arcsec 2a = 62.80 arcsec Uncertainty : ... ... Minor Axis (2b) : ... 2b = 46.47 arcsec Uncertainty : ... ... Axis Ratio : b/a = 0.740 b/a = 0.74 Uncertainty : ... ... Ellipticity : ... 1 - b/a = 0.26 Uncertainty : ... ... Eccentricity : ... [(a/b)2-1]/[(a/b)2+1] = 0.29 Uncertainty : ... ... Cos-1(b/a) : ... 42 deg Position Angle [Equinox] : 35 deg [J2000] 35 deg [J2000] Uncertainty : ... ... Significance : No uncertainty reported Diameter Reference Level : Diameter for "total" magnitude Frequency : 2.17 microns 1.38E+14 Hz Frequency Mode : Broad-band detector (e.g. photographic plate) Measurement Mode Detector Type : Maps (e.g., 2MASS, VLA, Sloan) Fitting Technique : Ellipse fitting to image Measured Quantity : Isophotal diameter Qualifiers : A radius is given in DIA_MAJ, not a diameter Coordinates Targeted : 267.502930 61.531769 (J2000) Qualifiers : From new, raw data NED Comment :
No. 4 Published Units: Homogenized Units: Reference Code : 1962MCG1..C...0000V Published Object Name : MCG +10-25-103 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 : 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 : 174918 +6132 (B1950) Qualifiers : From new, raw data NED Comment :
No. 5 Published Units: Homogenized Units: Reference Code : 1962MCG1..C...0000V Published Object Name : MCG +10-25-103 Frequency Targeted : POSS1 103a-O Major Axis (2a) : 1.20 arcmin 2a = 72.00 arcsec Uncertainty : ... ... Minor Axis (2b) : 2b = 0.50 arcmin 2b = 30.00 arcsec Uncertainty : ... ... Axis Ratio : ... b/a = 0.42 Uncertainty : ... ... Ellipticity : ... 1 - b/a = 0.58 Uncertainty : ... ... Eccentricity : ... [(a/b)2-1]/[(a/b)2+1] = 0.70 Uncertainty : ... ... Cos-1(b/a) : ... 65 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 : 174918 +6132 (B1950) Qualifiers : From new, raw data NED Comment :
No. 6 Published Units: Homogenized Units: Reference Code : 1991RC3.9.C...0000d Published Object Name : UGC 11008 Frequency Targeted : RC3 D_25, R_25 (blue) Major Axis (2a) : log(2a) + 1 = 1.09 2a = 73.80 arcsec Uncertainty : 0.06 10.90 arcsec Minor Axis (2b) : ... 2b = 30.77 arcsec Uncertainty : ... ... Axis Ratio : log(a/b) = 0.38 b/a = 0.42 Uncertainty : 0.05 0.05 Ellipticity : ... 1 - b/a = 0.58 Uncertainty : ... ... Eccentricity : ... [(a/b)2-1]/[(a/b)2+1] = 0.70 Uncertainty : ... ... Cos-1(b/a) : ... 65 deg Position Angle [Equinox] : 39 deg [J2000] 38 deg [J2000] Uncertainty : ... ... Significance : Mean error Diameter Reference Level : 25.0 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 : Isophotal diameter Coordinates Targeted : 175001.3 +613153. (J2000) Qualifiers : Homogenized from previously published data NED Comment :
No. 7 Published Units: Homogenized Units: Reference Code : 1991RC3.9.C...0000d Published Object Name : UGC 11008 Frequency Targeted : RC3 D_0 (blue) Major Axis (2a) : log(2a) + 1 = 1.11 2a = 77.30 arcsec Uncertainty : ... ... Minor Axis (2b) : ... ... Uncertainty : ... ... Axis Ratio : ... ... Uncertainty : ... ... Ellipticity : ... ... Uncertainty : ... ... Eccentricity : ... ... Uncertainty : ... ... Cos-1(b/a) : ... ... Position Angle [Equinox] : ... ... Uncertainty : ... ... Significance : No uncertainty reported Diameter Reference Level : 25.0 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 : Isophotal diameter Coordinates Targeted : 175001.3 +613153. (J2000) Qualifiers : Homogenized from previously published data NED Comment : Extinction and inclination corrected.

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