ES127_13m56s_NGC1976 (M42, Great Orion Nebula, Orion Nebula)

SIMPLE = T / file does conform to FITS standard

BITPIX = -32 / number of bits per data pixel

NAXIS = 3 / number of data axes

NAXIS1 = 5444 / length of data axis 1

NAXIS2 = 3803 / length of data axis 2

NAXIS3 = 3 / length of data axis 3

EXTEND = T / FITS dataset may contain extensions

COMMENT FITS (Flexible Image Transport System) format is defined in 'Astronomy

COMMENT and Astrophysics', volume 376, page 359; bibcode: 2001A&A...376..359H

BZERO = 0. / Offset data range to that of unsigned short

BSCALE = 1. / Default scaling factor

PROGRAM = 'Siril 1.4.0-beta4' / Software that created this HDU

DATE = '2025-10-06T11:56:28' / UTC date that FITS file was created

DATE-OBS= '2025-10-06T10:09:06.886626' / YYYY-MM-DDThh🇲🇲ss observation start,

ROWORDER= 'TOP-DOWN' / Order of the rows in image array

EXPTIME = 836.25 / [s] Exposure time duration

OBSERVER= 'DaveMartin' / Observer name

FILTER = 'Dual ' / Active filter name

FOCALLEN= 956.82 / [mm] Focal length

CENTALT = 43.875 / [deg] Altitude of telescope

CENTAZ = 197.023888888889 / [deg] Azimuth of telescope

XBINNING= 1 / Camera binning mode

YBINNING= 1 / Camera binning mode

XPIXSZ = 3.76 / [um] Pixel X axis size

YPIXSZ = 3.76 / [um] Pixel Y axis size

INSTRUME= 'ZWO ASI2600MC Pro' / Instrument name

CCD-TEMP= 0. / [degC] CCD temperature

SET-TEMP= 0. / [degC] CCD temperature setpoint

GAIN = 100 / Sensor gain

OFFSET = 12 / Sensor gain offset

CVF = 0.2636 / [e-/ADU] Electrons per A/D unit

FOCPOS = 19865 / [step] Focuser position

FOCTEMP = 8.30000019073486 / [degC] Focuser temperature

OBJECT = 'NGC1976 (M42, Great Orion Nebula, Orion Nebula)' / Name of the object

AIRMASS = 1.44068164488539 / Airmass at frame center (Gueymard 1993)

SITELAT = 39.3488888888889 / [deg] Observation site latitude

SITELONG= -78.8116666666667 / [deg] Observation site longitude

OBJCTRA = '05 35 15.799' / [H M S] Image center Right Ascension

OBJCTDEC= '-05 22 47.677' / [D M S] Image center Declination

RA = 83.8158281898562 / [deg] Image center Right Ascension

DEC = -5.37991021764815 / [deg] Image center Declination

CTYPE1 = 'RA---TAN-SIP' / TAN (gnomic) projection + SIP distortions

CTYPE2 = 'DEC--TAN-SIP' / TAN (gnomic) projection + SIP distortions

CUNIT1 = 'deg ' / Unit of coordinates

CUNIT2 = 'deg ' / Unit of coordinates

EQUINOX = 2000. / Equatorial equinox

CRPIX1 = 2693.5 / Axis1 reference pixel

CRPIX2 = 1938.5 / Axis2 reference pixel

CRVAL1 = 83.8212837066781 / [deg] Axis1 reference value

CRVAL2 = -5.38889204929805 / [deg] Axis2 reference value

LONPOLE = 180. / Native longitude of celestial pole

CDELT1 = -0.000225139323345704 / [deg] X pixel size

CDELT2 = 0.000225169400022428 / [deg] Y pixel size

PC1_1 = -0.348038991134063 / Linear transformation matrix (1, 1)

PC1_2 = -0.937480058801457 / Linear transformation matrix (1, 2)

PC2_1 = 0.937494027453252 / Linear transformation matrix (2, 1)

PC2_2 = -0.348001362769574 / Linear transformation matrix (2, 2)

A_ORDER = 3 / SIP polynomial degree, axis 1, pixel-to-sky

A_0_0 = 0.

A_1_0 = 0.

A_0_1 = 0.

A_2_0 = -1.64277020685452E-07

A_1_1 = 9.87549346279314E-09

A_0_2 = -8.69160424952199E-08

A_3_0 = -3.02073434291275E-10

A_2_1 = 5.06449749491843E-12

A_1_2 = -3.06521889392484E-10

A_0_3 = -7.11631122483371E-12

B_ORDER = 3 / SIP polynomial degree, axis 2, pixel-to-sky

B_0_0 = 0.

B_1_0 = 0.

B_0_1 = 0.

B_2_0 = -1.28288782073535E-08

B_1_1 = -5.68511798589425E-08

B_0_2 = -5.88039813473346E-08

B_3_0 = 2.51466443610045E-12

B_2_1 = -3.03411808507867E-10

B_1_2 = 1.88074302834745E-11

B_0_3 = -3.02158975629337E-10

AP_ORDER= 3 / SIP polynomial degree, axis 1, sky-to-pixel

AP_0_0 = -0.00282500133597869

AP_1_0 = -1.43205078008135E-05

AP_0_1 = 6.69821284630872E-07

AP_2_0 = 1.66963688254827E-07

AP_1_1 = -1.00792430236529E-08

AP_0_2 = 8.76805314355769E-08

AP_3_0 = 3.06432679354613E-10

AP_2_1 = -5.24743960913225E-12

AP_1_2 = 3.1135956544913E-10

AP_0_3 = 6.95417774079078E-12

BP_ORDER= 3 / SIP polynomial degree, axis 2, sky-to-pixel

BP_0_0 = -0.000587530962498615

BP_1_0 = 6.73660948648711E-07

BP_0_1 = -1.0370590796116E-05

BP_2_0 = 1.30208895607198E-08

BP_1_1 = 5.76814378001768E-08

BP_0_2 = 5.93230277432801E-08

BP_3_0 = -2.60709033909064E-12

BP_2_1 = 3.07758434362221E-10

BP_1_2 = -1.92588333919524E-11

BP_0_3 = 3.05579270177439E-10

PLTSOLVD= T / Siril internal solver

HISTORY Plate Solve

HISTORY Crop (x=431, y=223, w=5444, h=3803)

HISTORY Background extraction (Correction: Subtraction)

HISTORY StatStretch: m=0.20 l=True n=True c=True b=0.00

HISTORY GraXpert AI BGE: subtraction

HISTORY GraXpert AI denoise: strength 0.50

HISTORY GraXpert AI deconvolve: strength 0.50

HISTORY GraXpert AI deconvolve: strength 0.50

HISTORY GHS LINEAR BP: 0.08

HISTORY GHS pivot: 0.138, amount: 1.25, local: 0.00 [0.00 1.00]

HISTORY GHS LINEAR BP: 0.06

HISTORY GHS INV pivot: 0.116, amount: 0.82, local: 0.00 [0.00 1.00]

HISTORY Apply Signature

HISTORY GHS pivot: 0.179, amount: 2.38, local: 0.00 [0.00 1.00]

HISTORY GHS LINEAR BP: 0.03

ADCBITS = 16 / Bit depth of camera sensor ADC in current mode

BIASADU = 121.16593933105469 / ADU for bias level (no photons) at current sett

CAMID = '1E1E560D0B020900' /

COLORTYP= 'RGB' /

DATE-AVG= '2025-10-06T10:24:13.1694766' / System Clock:Est. Frame Mid Point

DATE-END= '2025-10-06T10:39:19.4523264' / System Clock:Est. Frame End

EGAINSAV= 0.26355 / Electrons per ADU at saved bit depth

JD_UTC = 2460954.933485758 / Julian Date at mid exposure

PIERSIDE= 'EAST' /

RDNOISE = 1.77 / Read noise in electrons

RELGAIN = 2.964 / Multiplicative gain relative to minumum

SUBEXP = 3.75 /

END

Done