M81 and M82: Ha and Oiii integration to RGB

No Comments


During 2021 and 2022 I took a good number of subframes focusing on M81 and M82 field and I planned to integrate RGB channels with Ha and Oiii narrowband contribute.

Being a follower of John Rista short time DSO photography approach, RGB channel subframes I recorded at 60″, Halpha and Oiii subframes at 180″, William Optics Redcat51 and ASI1600mm Pro at -20 Celsius, Gain 139.

For Rista excellent studies, please cfr. https://jonrista.com/the-astrophotographers-guide/the-zwo-asi1600-guide/the-zwo-asi1600/preliminary-analysis/ and https://www.cloudynights.com/topic/578198-short-exposure-time-asi-1600mm-cool/ both on 02/08/2023.

After standard calibration, cosmetic correction by dark-master, star registration and winsorized sigma clipping integration, I obtained masterframe for each channel recorded.

Channel combination of RGB generated a good integration which I played with Ha and Oiii masters to Dynamic BG removal, solving (and annotated transparent layer version for further work), Spectrophotometric Color Calibration (just RGB) deconvolution and denoising.

I then proceed by starXterminator in starless and stars version of each master to work properly ‘till putting them back by PixelMath, obtaining a pretty good RGB master

with ready-to-go Halpha and Oiii narrowband master to integrate within:

H alpha channel to be associated to R channel while Oiii to differently be integrated with both G and B channels.

Narrowband with RGB integration produced a pretty good result which, in turns, I little worked over separating again stars and starless sub-master, finally directly melted in Photoshop.

This portion of sky is so rich of galaxies; PGC annotation (PixInSight) gives an idea of the richness of field

I thus start to try some crop solution for better framing and focusing the final image. At first I cropped a squared and a vertical version to catch in the field also NGC2976, NGC2961 and NGC2959.

Finally I focused about M81 and M82 with a deep cropping for an orizontal composition, trying to dispose M81 and friends according to 3/4 grids basic composition rule.

Photoshop, non cropped version, with 3 main crops framing as guide layer are available here

Sh2-132 (LBN 473) in HOO: a deep study of Lion Nebula

No Comments

According to Stewart Sharpless annotation, 1959 “A Catalogue of Hii Regions” U.S. Naval Observatory, 10 Sept. 1959 [ https://articles.adsabs.harvard.edu/pdf/1959ApJS….4..257S ], Sh2-139 is “Part of II Cep association” a wide and luminous OB spectral type stellar association situated at a distance of about 3.200 parsec, or 10.400 light years, within the Perseus Arm, one of the 2 major spiral arms of our galaxy. 

Cfr.: Churchwell Ed, Babler Brian L., Meade Marlin A. 2009 “The Spitzer/GLIMPSE Surveys: A New View of the Milky Way” Publications of the Astronomical Society of the Pacific. 121: 213–230. https://ui.adsabs.harvard.edu/abs/2009PASP..121..213C/abstract

Sh2-132 complex is featured by a bright optical nebula with an intense central region (Ø = 25’) surrounded by more diffuse emission ( Ø ~ 1*). Low resolution radio studies have shown it to be an intense radio source with a strong central core contained into a more diffuse envelope. 

Churchwell and Walmsley 1973 analysis confined that the total emission is thermal nature, featured by a spectrum flatted down to 0.408 GHz, typical of a low Hii density region. 

Cfr. Churchwell E. , Walmsley C. M. , 1973 “Observation of Optical Nebula at 2695 Mhz ” in Astron. Astrophys. 23: 117

Nebula analysis shows two distinct regions separated by an area, running from NW to SE, with little or no emission. 

The optical emission in the eastern region is quite mottled, with areas of bright emission and patches of obscuring materials. Western region is instead featured by little or no obscuring matter. 

According to Lynds 1962 Catalogue of Dark Nebulae there are three main dark nebulae classified as LDN 1150, LDN 1154 and LDN 1162; Cfr. https://heasarc.gsfc.nasa.gov/W3Browse/nebula-catalog/ldn.html

Strong central features and western/eastern regions strong/weaker emission are confirmed by radio analysis at 0.408 GHz and 1.4 GHz conducted respectively by Felli et al. 1977a and Felli and Churchwell 1972. 

According to Van der Hucht 2001 and Hamman et al. 2006 among those very hot and massive stars responsible for the ionization of gasses, notable consideration have to be taken about two Wolf-Rayet subjects, known as HD 211564 and HD 211853 (or WR 153), featured by a huge bubble well visible in radio emissions identified as Shell B, which scholars suggest to be originated from strong stellar wind from these massive star, featured after Harten et al. 1978 study by a non uniform emission specially on the eastern side where there is essentially no emission at all.

Similar smaller structure, named Shell A, bubbles around a class K star. 

Cfr. Van der Hucht K. A. , 2001 “VizieR Online Data Catalog: 7th Catalog of Galactic Wolf-Rayet stars” in NewAR,45, 135. https://ui.adsabs.harvard.edu/abs/2001yCat.3215….0V/abstract

Hamann W. R., Gräfener G. , Liermann A. , 2006 A&A,70, 205. https://ui.adsabs.harvard.edu/abs/2006A%26A…457.1015H/abstract 

According to Dubout-Crillon 1976 catalogue, lion’s bottom and tail shaped like portion is made by a thin strip of emission extending to the south of the eastern region featured by a faint Halpha ridge. 

Cfr. Dubout-Crillon R. 1976 “H II regions of the northern Milky Way: medium-large-field photographic atlas and catalogue” in Astronomy and Astrophysics, Suppl. Ser., Vol. 25, p. 25 – 54. https://adsabs.harvard.edu/full/1976A%26AS…25…25D

According to Avedisova 2002 it is plausible to hypothesize that this nebula was setting of some chain processes of star origin. 

Avedisova, V. S., A Catalog of Star-Forming Regions in the Galaxy, in Astronomy Reports, vol. 46, n. 3, marzo 2002, pp. 193-205. https://ui.adsabs.harvard.edu/abs/2002ARep…46..193A/abstract

Harten et al. 1978 studies of radio emission of this Hii region results indicated that 2/3 of the radio emissions originates in features larger then 10’ in diameter, suggesting that total mass and low electron density placed Sh2-132 as a member of evolved giant Hii region. 

Helou and Walker studies of infrared sources identified and cataloged within the nebula nine sources of infrared radiation, while Wouterloot and colleagues 2013 identified an H2O maser source. 

Helou, George; Walker, D. W., Infrared astronomical satellite (IRAS) catalogs and atlases. Volume 7: The small scale structure catalog, in Infrared astronomical satellite (IRAS) catalogs and atlases, vol. 7, 1988, pp. 1-265. https://ui.adsabs.harvard.edu/abs/1988iras….7…..H/abstract

Wouterloot, J. G. A.; Brand, J.; Fiegle, K., IRAS sources beyond the solar circle. III – Observations of H2O, OH, CH3OH and CO, in Astronomy and Astrophysics Supplement Series, vol. 98, n. 3, maggio 1993, pp. 589-636. URL consultato il 21 marzo 2013. https://ui.adsabs.harvard.edu/abs/1993A%26AS…98..589W/abstract

The development of infrared astronomy gives chances to scholars like Saurin and colleagues 2009 to explore Sh2-132 Hii regions and studied its Hii region as a star forming region and embedded star clusters complex. 

Grounding on Harten et al. 1978 radio continuum emission as indication of giant nature of this complex and its evolved character, Saurin hypothesized that Sh-132 could be suitable laboratory for early dynamical and hydrodynamical evolution, and by R-band Digitalized Sky Survey imaging of the whole complex they confirm 2 previous identified open cluster

  • Teutsch 127a – optical embedded open cluster, includes Trap 900
  • and Berkley 94a – optical open cluster on the outskirts of the complex

And discovered 4 new open cluster:

  • SBB1 – infrared embedded cluster with IRAS 22172+5549,
  • SBB2 – optical embedded cluster with bow-shock
  • SBB3 – Compact optical open cluster surrounding WR 152
  • SBB4 – Optical open cluster on the outskirts of the complex. 

Cfr. Saurin T. A. , Bica E. , Bonatto C. , 2010 “Star clusters in the Sh2-132 complex: clues about the connection between embedded and open clusters” in journal of Royal Astronomical Society, 407, 133-143 (2010) https://academic.oup.com/mnras/article-pdf/407/1/133/3067396/mnras0407-0133.pdf

Sh2-132 (LBN 473) “Lion Nebula” in SHO

No Comments




Crop and Starless

Sh2-129, Ou4 in SHO palette

No Comments

Sh2-129 emission nebula presents an irregular ring-arch form which resemble a figure of a flying bat, and according to Blitz et.Al. is situated at a distance of about 400 parsec or 1300 light-years.

According to Dobashi and collegues the region sourroundig Sh-129 is particularly rich of molecular clouds, first among all the whide obscure nebulositys system occulting the Milky Way in the direction of Cefeus; cfr. Dobahashi K. et Al., 1994 “Molecular Clouds in Cygnus. I. A Large-Scale 13CO Survey” – https://ui.adsabs.harvard.edu/abs/1994ApJS…95..419D/abstract

George Helou and collegues [ https://ui.adsabs.harvard.edu/abs/1988iras….7…..H/abstract ] studied the infrared radiation source IRAS 21168+5948 which coordinates coincide with the CO emission region, as just introduced within Avedisova Star Formation regions Catalogue; cfr. Avedisova V. S., 2002 “A Catalog of Star-Forming Regions in the Galaxy” in Astronomy Reports, vol.46 n.3: 193 – 205.

Within Sh2-129 center, recording in Oiii narrowband, is possible to enhance the vision of Ou4 nebula, whose form gave the name of squid nebula.

Discovered in 2011 by French astro-imager Nicolas Outters, the Squid Nebula’s alluring bipolar shape is distinguished by the telltale blue-green emission from doubly ionized oxygen atoms. Though apparently completely surrounded by hydrogen emission region Sh2-129, the true distance and nature of the Ou4 have been difficult to determine. 

Recent investigation suggests Ou4 really does lie within Sh2-129 some 2,300 light-years away. Consistent with that scenario, Ou4 would represent a spectacular outflow driven by HR8119, a triple system of hot, massive stars seen near the center of the nebula. 

The truly giant Squid Nebula would physically be nearly 50 light-years across.

This work is the result of personal SHO records using William Optics Redcat 51 and ASI1600mm Pro under Bortle 6 sky in Livorno – Italy (home balcony) with integration of records focused about Oiii signal obtained by Takahashi FSQ-106EDX4 and Proline FLI PL16083 camera retrieved from Telescopelive.

Data framelists set available:

here for WO51, 

and here for Takahashi106

PixInSight cored workflow for generate 2 distinguished single channel SHO masters, linear-fit by Takahashi Oiii master, each pair blended by pixelmath within final S H and O masters, channel-combined in the SHO integration.

Normal narrowband workflow post-proccessing followed ‘till reaching an SHO starless

and SHO stars separated masters.

The same workflows I took for RGB channels, with the focus on star – separated from starless final integration to be used for final image composing.

I then integrated in Photoshop by screen blending mode after necessary fixing and adjustements.

Parallely, the same workflow I made for Oiii master, using Oiii starless for enhancing Ou4 structure, luminosity and tones, in Photoshop by adjustements and colorizing filtered layer.

Integration of Oiii starless channel within SHO master enhanced luminosity, saturation and structure of Ou4 whole nebula.

Simeis 147 Sh2-240 in SHO palette

No Comments

Simeis 147 in SHO palette.

Astrobin: https://www.astrobin.com/5vg3w9/

Astrometry: https://nova.astrometry.net/user_images/7641616#annotated

Sh2-240 annotation by PixInSight

PixInSight workflow to get starless and star separated masters by Starnet2 from SHO channel combination integration, this latter used as luminance level; files not stretched hereby available:

Sh2-240 Starless: https://www.dropbox.com/s/40ijqgs488vv3bs/SHO_Gain139_DBEspccDECONVexdenoiseSTARLESS.xisf

Sh2-240 Stars: https://www.dropbox.com/s/mypn8s4xao7piix/SHO_Gain139_DBEspccDECONVexdenoiseSTARLESSstars.xisf

Sh2-240 SHO integration (ABE, SPCC, Deconvolutio, DENOISE) : https://www.dropbox.com/s/8dp76br7d9kiw92/SHO_Gain139_DBEspccDECONVexdenoise.xisf

Photoshop postproduction, layer .psd master available here: https://www.dropbox.com/s/zksyulh7yxzd0eq/Sh2-240-SHO_Gain139_DBEspccDECONVexdenoiseSTARLESS%26stars%26luminance-stretchedPP.psd

Spectrophotometric Color Calibration White balance values, by PixInSight

C/2022 E3 ZTF 28, 29/01/2023

No Comments
C/2022 E3 ZTF, night between 28 and 29/01/2023. 120″ and 60″ subframes


Astrometry: https://nova.astrometry.net/user_images/7357487#annotated

Starless comet standalone integration: PixInSight, Starnet
White balance parameters by PixInSight > Spectrophotometric Color Calibration


No Comments
Telescopi o obiettivi di acquisizione: William Optics RedCat 51 Petzval APO
Camere di acquisizione: ZWO ASI183MC Pro
Montature: SkyWatcher AZ-GTI  ·  Skywatcher EQ35M
Telescopi o obiettivi di guida: QHYCCD QHY Mini Guide Scope
Camere di guida: QHYCCD QHY5L-II-C
Software: Pleiades Astrophoto PinInsight  ·  Lightroom  ·  Stark Labs Phd2  ·  Photoshop  ·  Astroberry  ·  KStars Ekos/INDI, Astroberry OS
Filtri: SVBONY SII Filter 2″  ·  SVBONY H-Alpha 7nm  ·  SVBONY OIII 18nm
Accessorio: SVBONY Filter Wheel 2″

Date:22 Aprile 2021 ,  23 Aprile 2021 ,  24 Aprile 2021 ,  02 Maggio 2021 ,  08 Maggio 2021 ,  27 Maggio 2021 ,  31 Maggio 2021 ,  01 Giugno 2021 ,  03 Giugno 2021 ,  09 Giugno 2021 ,  12 Giugno 2021 ,  13 Giugno 2021 ,  14 Giugno 2021 ,  15 Giugno 2021 ,  17 Giugno 2021 ,  22 Giugno 2021 ,  26 Giugno 2021 ,  27 Giugno 2021 ,  28 Giugno 2021 ,  29 Giugno 2021 ,  01 Luglio 2021 ,  05 Luglio 2021 ,  06 Luglio 2021 ,  09 Luglio 2021 ,  12 Luglio 2021 ,  14 Luglio 2021
SVBONY H-Alpha 7nm: 56×300″ (4h 40′) (gain: 180.00) -15C bin 1×1
SVBONY H-Alpha 7nm: 245×300″ (20h 25′) (gain: 180.00) 0C bin 1×1
SVBONY OIII 18nm: 106×300″ (8h 50′) (gain: 180.00) -15C bin 1×1
SVBONY OIII 18nm: 20×300″ (1h 40′) (gain: 180.00) 0C bin 1×1
SVBONY SII Filter 2″: 106×300″ (8h 50′) (gain: 180.00) -15C bin 1×1
Integrazione: 44h 25′
Dark: ~28
Flat: ~28
Dark dei flat: ~28
Giorno lunare medio: 15.51 giorni
Fase lunare media: 46.90%
Scala del Cielo Scuro Bortle: 6.00

Astrometry.net job: 4776216
Centro AR: 20h 23′ 13″
Centro DEC: +40° 47′ 59″
Campionamento: 1,989 arcsec/pixel
Orientazione: 125,144 gradi
Raggio del campo: 1,768 gradi

Astrobin: https://www.astrobin.com/zhd4gn/


An SHO palette integration for NGC6910 field.
Subrfames recorded by William Optics Redcat 51 and ASI183MC-Pro with 2″ Svbony Ha, Sii, Oiii narrowband filters.
Drizzle data integration and postproduction by PixInSight, Photoshop and Lightroom.
Subframe list as follow:
WO51 ASI183 AZGTi NGC6910 -15C Ha G180 300s_26062021 16
WO51 ASI183 AZGTi NGC6910 Ha -15C G180 300sec_22062021 17
WO51 ASI183 NGC6910 Ha -15C G180 300sec AZGTi_01072021 23
WO51 ASI183 NGC6910 Ha G180 300sec_08052021 26
WO51Redcat ASI183 Ha NGC6910 G180 300s_03062021 26
WO51Redcat ASI183 Ha NGC6910 G180 300sec_01062021 28
WO51Redcat ASI183 Ha NGC6910 Gain180 300sec_27052021 29
WO51Redcat ASI183MC-Pro Ha NGC6910 G180 300sec_31052021 30
WO51Redcat ASI183MC-Pro Ha NGC6910 Gain180 300sec_02052021 21
WO51Redcat ASI183MC-Pro Ha NGC6910 Gain180 300sec_08052021 26
WO51Redcat ASI183MC-Pro Ha NGC6910 Gain180 300sec_22042021 7
WO51Redcat ASI183MC-Pro Ha NGC6910 Gain180 300sec_23042021 28
WO51Redcat ASI183MC-Pro Ha NGC6910 Gain180 300sec_24042021 24

WO51 ASI183 NGC6910 Sii -15C G180 300sec AZGTi_06072021 13
WO51 ASI183 NGC6910 Sii -15C G180 300sec AZGTi_09072021 15
WO51 ASI183 NGC6910 Sii -15C G180 300sec AZGTi_12072021 22
WO51 ASI183 NGC6910 Sii -15C G180 300sec AZGTi_14072021 13
WO51 ASI183 NGC6910 Sii -15C G180 300sec AZGTi_28062021 18
WO51 ASI183 NGC6910 Sii -15C G180 300sec AZGTi_29062021 13
WO51ASI183 NGC6910 Siii -15C G180 300sec AZGTi_12072021 12

WO51 ASI183 AZGTi NGC6910 -15C Oii G180 300sec_27062021 15
WO51 ASI183 NGC6910 Oiii -15C G180 300sec AZGTi_05072021 18
WO51Redcat ASI183 -15C Oiii NGC6910 G180 300sec_15062021 21
WO51Redcat ASI183 -15C Oiii NGC6910 G180 300sec_17062021 21
WO51Redcat ASI183 Oiii -15C NGC6910 G180 300sec_13062021 15
WO51Redcat ASI183 Oiii -15C NGC6910 G180 300sec_14062021 16
WO51Redcat ASI183MC-Pro Oiii NGC6910 G180 300sec_09062021 20

Map of NGC6910 region in BW/inverted color. Labels by PixInSight image solver and render annotation scripts.

IC1396 region in SHO palette

No Comments



M102, NGC5967, NGC5906

No Comments


Astrometry: http://nova.astrometry.net/user_images/4854083#annotated

M92 / NGC6341

No Comments

Astrobin: https://www.astrobin.com/sgo4uc/

Astrometry: http://nova.astrometry.net/user_images/4848320#annotated

Social Widgets powered by AB-WebLog.com.