ES171_32m0s_SH2-131 (Elephant's Trunk Nebula)

SIMPLE = T / file does conform to FITS standard

BITPIX = -32 / number of bits per data pixel

NAXIS = 3 / number of data axes

NAXIS1 = 5374 / length of data axis 1

NAXIS2 = 3820 / 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-beta3' / Software that created this HDU

DATE = '2025-09-23T17:47:54' / UTC date that FITS file was created

DATE-OBS= '2025-09-19T02:13:29.072693' / YYYY-MM-DDThh🇲🇲ss observation start,

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

EXPTIME = 1920.000032 / [s] Exposure time duration

OBSERVER= 'DaveMartin' / Observer name

FILTER = 'L_Enhance' / Active filter name

FOCALLEN= 958.112 / [mm] Focal length

CENTALT = 71.6030555555556 / [deg] Altitude of telescope

CENTAZ = 5.9475 / [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= -10. / [degC] CCD temperature

SET-TEMP= -10. / [degC] CCD temperature setpoint

GAIN = 100 / Sensor gain

OFFSET = 12 / Sensor gain offset

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

FOCPOS = 19517 / [step] Focuser position

FOCTEMP = 16.6800003051758 / [degC] Focuser temperature

OBJECT = 'SH2-131 (Elephants Trunk Nebula)' / Name of the object of interest

AIRMASS = 1.05356136208347 / Airmass at frame center (Gueymard 1993)

SITELAT = 39.3488888888889 / [deg] Observation site latitude

SITELONG= -78.8116666666667 / [deg] Observation site longitude

OBJCTRA = '21 38 58.944' / [H M S] Image center Right Ascension

OBJCTDEC= '+57 33 31.320' / [D M S] Image center Declination

RA = 324.74560100456 / [deg] Image center Right Ascension

DEC = 57.5587000403959 / [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 = 2687.5 / Axis1 reference pixel

CRPIX2 = 1910.5 / Axis2 reference pixel

CRVAL1 = 324.74560100456 / [deg] Axis1 reference value

CRVAL2 = 57.5587000403959 / [deg] Axis2 reference value

LONPOLE = 180. / Native longitude of celestial pole

CDELT1 = -0.000224840737847169 / [deg] X pixel size

CDELT2 = 0.000224860686602583 / [deg] Y pixel size

PC1_1 = 0.345744287250735 / Linear transformation matrix (1, 1)

PC1_2 = 0.938328773849274 / Linear transformation matrix (1, 2)

PC2_1 = -0.938330570167512 / Linear transformation matrix (2, 1)

PC2_2 = 0.345739412114258 / 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 = 5.62564045790263E-08

A_1_1 = -1.44264003374099E-07

A_0_2 = -2.62907849874921E-09

A_3_0 = -3.16722349744606E-10

A_2_1 = 1.10599484828326E-11

A_1_2 = -3.13649695720793E-10

A_0_3 = -2.23342416999306E-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 = -7.65455501576803E-08

B_1_1 = 7.05967389567685E-08

B_0_2 = -2.20775092582202E-07

B_3_0 = 2.07382079385262E-12

B_2_1 = -3.09765514137844E-10

B_1_2 = 7.27794524422538E-12

B_0_3 = -3.12142597386793E-10

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

AP_0_0 = 0.00102900889780615

AP_1_0 = -8.9930598753396E-06

AP_0_1 = 1.62058670307354E-07

AP_2_0 = -5.70851768899143E-08

AP_1_1 = 1.45881422780918E-07

AP_0_2 = 2.29168096201055E-09

AP_3_0 = 3.20298307622995E-10

AP_2_1 = -1.12667726861887E-11

AP_1_2 = 3.17553833757912E-10

AP_0_3 = 2.1819750011648E-12

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

BP_0_0 = -0.00118456837575966

BP_1_0 = -4.72855830088711E-08

BP_0_1 = -5.87266749085824E-06

BP_2_0 = 7.73338718101097E-08

BP_1_1 = -7.13332111664078E-08

BP_0_2 = 2.22521972331902E-07

BP_3_0 = -2.11218047480999E-12

BP_2_1 = 3.13215408322911E-10

BP_1_2 = -7.32837439405831E-12

BP_0_3 = 3.14814106367671E-10

PLTSOLVD= T / Siril internal solver

HISTORY Crop (x=138, y=47, w=5374, h=3820)

HISTORY Plate Solve

HISTORY Photometric CC (algorithm: SPCC)

HISTORY Trail Removal

HISTORY Trail Removal

HISTORY Trail Removal

HISTORY Background extraction (Correction: Subtraction)

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

HISTORY StatStretch: m=0.30 l=True n=True c=True b=0.00

HISTORY GHS LINEAR BP: 0.13

HISTORY GHS LINEAR BP: 0.03

HISTORY GHS pivot: 0.180, amount: 1.93, local: 0.00 [0.11 1.00]

HISTORY GHS INV pivot: 0.264, amount: 1.66, local: 0.00 [0.00 1.00]

HISTORY GHS pivot: 0.247, amount: 1.60, local: -2.23 [0.00 1.00]

HISTORY GraXpert AI denoise: strength 0.50

HISTORY GraXpert AI deconvolve: strength 0.50

HISTORY Saturation enhancement (amount=-0.37)

HISTORY SCNR (type=average neutral, amount=1.00, preserve=true)

HISTORY Curves Transformation with 3 points

HISTORY Curves Transformation with 3 points

PIERSIDE= 'WEST' /

CAMID = '1E1E560D0B020900' /

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

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

EGAINSAV= 0.26355 / Electrons per ADU at saved bit depth

RELGAIN = 2.964 / Multiplicative gain relative to minumum

RDNOISE = 1.77 / Read noise in electrons

SUBEXP = 60.000001 /

COLORTYP= 'RGB' /

DATE-END= '2025-09-19T02:48:03.6317295' / System Clock:Est. Frame End

DATE-AVG= '2025-09-19T02:30:46.3522115' / System Clock:Est. Frame Mid Point

JD_UTC = 2460937.6047031507 / Julian Date at mid exposure

END

Done