Collecting  Photons

NGC 224 - M 31 (Andromeda)

The closest galaxy of all in technicolor. ASA 10" and STL 11000. LRGB 6 hours in two nights.

NGC 224 - M 31 (Andromeda)

The Andromeda galaxy and the satellites. A deep shot that reveals some of the outer halo of the galaxy and a dim bar joining it with the satellite galaxy M110. To capture the full extension of the galaxy I made a two part mosaic to build the galaxy outline and the surrounding star field (152x4' subs for each frame). The central part of the galaxy has been reinforced with additional 66x4' exposures. Finally, the red layer has been blended with 97x8' exposures through the narrowband Ha filter to bring out the small and delicate HII region in the spiral arms. Measuring an equalized black and white version of this picture I found out that the galaxy outer edges can be traced to a size of over 206 arc min, almost 3 degree and half! In total the image required over 37 hours of integration in 10 nights. Modified Canon 350D, Megrez 80, 384 mm.

NGC 598 - M 33 (Triangulum)

The large Pinwheel galaxy. Such a gorgeous target deserved a major multi-night effort: ASA 10 f6.3, modified Canon 350D, 53X8'. The picture shows many HII areas, see the link for more details. North is to the right. An old picture shot with the C8 is visible here (C8, f6.3, 350D, 53X8').

NGC 598 - M 33 (Triangulum)

This image comes from a collaboration with Danilo Pivato. He provided a wonderfully detailed luminance obtained with his Tak BRC 250 that I completed with my own colour data obtained with the ASA astrograph. North is up.

NGC 628 - M 74 (Pisces)

A beautiful face-on spiral galaxy (10.5'x9.5'). C8, f6.3, modified Canon 350D, 18X8'.

NGC 2403 (Camelopardalis)

A very large (21.9'X12.3'') galaxy with a low surface luminosity (8.9, integrated). This galaxy is very blue with numerous knots delineating the spiral arms.  29X8' iso 800; Canon 350D, C8 f 6.3. I have used a complex set of spatial masks to lift the galaxy levels while keeping the crowded star field at bay.

NGC 2859 (Leo Minor)

A lousy picture of a small and difficult subject: a very peculiar barred galaxy in Leo Minor (4.5'X4.0'). The spiral arms have detached from the central bar and appear as a faint ring. In the larger image, two more faint galaxies are visible immediately north.

21X8' iso 400; Canon 300D, C8 f 6.3. Offset, dark, flat, hyperbolic sine stretch to maximize differences in colour. Final levels  in Photoshop CS.

NGC 2903  (Leo Major)

A splendid and isolated galaxy in Leo's sickle (mag 8.8, 12.6'X6.0'). A barred spiral rich in dust and with unusually dim outer arms. Three nights of collection for a total of 65x8' exposures (about 8.5 hr; 12, 13, 14 March, 2007).  I prepared a luminance channel from the best subset of frames that has been mildly deconvoluted to provide the star images and the knots in the brightest area of the galaxy. This has been combined with the remaining data for the outer arms. Finally the image has been sharpened with a multiscale wavelet filter.

See here, for an embarrassing old shot made with the 300. 25X8' iso 400 collected in two different night; C8 f 6.3.

Field around M96 (Leo Major)

A lovely field with four large galaxies. From the right we encounter first M95 (NGC 3351, 7.4'x5.0') a beautiful barred spiral (SBb) surrounded by an obvious disk. Further east we encounter M96 (NGC 3368, 7.8'x5.2'). This is a virtual twin of M95 with a bar (SBab) making this couple a very unusual pair. To the north there is a close triplet framed by (in order of decreasing size) M105 (NGC 3379, 5.3'x4.8') an E1 elliptical galaxy, NGC 3371 (5.4'x2.7', E/SB0) and NGC 3373 (2.9'x1.3', Sc). Notice the colour difference between the element of this group.

Megrez super Apo, 80 mm, 0.8 TV reducer/flattener, f 4.8. 28X8' iso 800; Canon 350D, Offset, dark, flat, hyperbolic sine stretch in Iris. Background subtraction with PixInsight. Final curves and and selective unsharp masking in Photoshop CS, noise reduction with NeatImage Pro.

M96 - NGC 3368 (Leo Major)

A close up of M96, C8, f6.3. 39X8', iso 800. Modified Canon 350D. Offset, dark, flat, hyperbolic sine stretch for the outer ring and DDP for the core in Iris. Background subtraction and masked curves operation with PixInsight. Deconvolution of the luminance channel in Iris. Final touches and and selective unsharp masking in Photoshop CS, noise reduction with NeatImage Pro.

NGC 3627 - M 66, NGC 3623 - M65, NGC 3628 (Leo Major)

The Leo triplet formed by the galaxies (clockwise from the top) NGC 3628 (13.1' x 3.1'), M65 (9.8' x 2.9')and M66 (9.1' x 4.1'). Scores of lesser galaxies can be discerned in the high resolution image.  An highly stretched image shows the 80 kparsec tidal tail of NGC 3628 caused by the interaction with the two companions. See for example "STAR FORMATION IN THE TIDAL TAIL OF THE LEO TRIPLET GALAXY NGC 3628" by Chromey et al. 1998. 

 Click here for a composition of the entire triplet (total of 62 sub exposures collected in four different nights). Published on the July 2005 issue of "Le Stelle".

Markarian chain (Virgo)

The Markarian chain is an association of galaxies at the core of the Virgo cluster. The two giant eliptical M84 and 86 dominate the center of the group while at the east (left) sits the heavily distorted couple NGC 4438 and 4435. M87 is visible to the south. The field includes thousands of galaxies: indeed, most of the faintest star-like objects are galaxies, as it can be seen comparing the image to the Sloane digital survey. See here for the labelled overlay.

Two nights during a lousy early spring. ASA 10", f3.6. STL 11000, RGB 14x8' per channel. No luminance. Published on Coelum magazine and on the May 2010 issue of Sky and Telecope.

Markarian chain (Virgo)

Wide field image of the Markarian chain. Tens of galaxies and and asteroid track (Sulsiva). See here for the labelled overlay.

Megrez fluo triplet, 80 mm f6.0.  Offset, dark, flat, hyperbolic sine stretch. Final levels and unsharp masking with PixInsight and Photoshop CS. February 1-2, 2006.  Published on the June 2006 issue of "Le Stelle".

NGC 4321 - M100 (Coma Berenices)

M100 is a beautiful face on spiral (SBbc, 7.5'x6.1'). The field is cluttered with smaller galaxies: see here for the labelled overlay. 8 ghr 32' in total in two nights.

An old shot taken with the 300D can be seen here. 41x8', iso 400. Canon 300D, C8 f 6.3.  Offset, dark, flat, hyperbolic sine stretch. Final levels, masked curves and unsharp masking with PixInsight and Photoshop CS. March 15-16, 2005.

M58, NGC 4564, NGC 4567 and NGC 4568 (Virgo)

A family portrait in Virgo that include a famous interacting pair: the Siamese twins galaxies. A collaboration with John Carver and his marvellous ASA 16". About 8 hrs of integration.

NGC 4565 (Coma Berenices)

24X8' iso 400 collected on three nights; Canon 300D, C8 f 6.3. Offset, dark, flat, hyperbolic sine stretch. Final levels and unsharp masking in Photoshop CS. 

NGC 4631 - NGC 4627 - NGC 4656 (Canes Venatici)

ASA 10", f3.6 STL 11000. Pure RGB composite, 11x8' per channel in two nights.

NGC 4725 (Coma Berenices)

A good looking pair and a distorted one. On the left the peculiar galaxy NGC 4725 (mag 9.3, 10.7'x7.6') has a massive bar surrounded by a ring and a very faint outer arm (SBab/P). Notice the colour difference between the bar and the  ring. On the right NGC 4712 (mag 12.5, 2.3'x0.9') is a regular spiral (Sbc) seen about 50° from the front. The link shows also the distorted tidal tail of NGC 4726.

See here and older shot taken with my pre-Galileian equipment. 47X8' iso 400 collected on three nights (over 6 hours in total) in a very mediocre sky (mag 3.5-4 at the zenith); Canon 300D, C8 f 6.3.  

NGC 4826 - M64 (Coma Berenices)

This is the Blackeye galaxy (mag 8.5, 10'x5.4') celebrated because of the asymmetric dark area of dusts. In 2008 I did a new and much deeper shot with the modified 350D (Celestron 8, 68x8' subs in two nights on May 5 and 8). With my great surprise the resulting image shows some fine details in the dust cloud itself. I used a very quick but effective procedure in Photoshop CS to implement a crude multiscale filtering. The procedure is detailed here.

An old version shot with the non modified 300D. 16X8' iso 400; Canon 300D, C8 f 6.3. Offset, dark, flat, hyperbolic sine stretch. Final levels and unsharp masking in Photoshop CS. 

NGC 3031 - M 81 (Ursa Major)

One of the great wonders of sky. Large (26'X14') and bright (6.9) with a marvellous colour contrast between spiral arms and dustier nucleus. Notice several dark lanes and numerous blue stars resolved in the arms. The faint path on the left is the galaxy Holmberg II: this is a dwarf galaxy in the M81 group. 

31X8' over 4 hours of exposure, iso 400. Offset, dark, flat, hyperbolic sine stretch to maximize differences in colour. Final levels and unsharp masking in Photoshop CS. Canon 300D, C8 f 6.3. Published on the July 2005 issue of "Le Stelle".

NGC 3034 - M 82 (Ursa Major)

A peculiar and very active galaxy nearby M81(13'X6'). 

37X8', iso 400. The stack has been processed with the aim of maximizing resolution and colour differences. In brief the final image is the composite of a luminance layer obtained by converting the added stack to black and white and then processing through a Richardson-Lucy algorithm. The chroma layer has been processed through a hyperbolic sine stretch. Final composition in the Lab mode in Photoshop CS. Canon 300D, C8 f 6.3.  Published on the July 2005 issue of "Le Stelle".

Region of M81 - 82 (Ursa Major)

Wide field image. On the top-left corner is visible the associated galaxy ngc 3077 (5.2'x4.7').

Megrez 80, 600 mm, 350D, 36X8' over 4 hours of exposure, iso 800. Offset, dark, flat, hyperbolic sine stretch to maximize differences in colour. Final levels and unsharp masking in Photoshop CS.

M81 - 82 (Ursa Major)

A mosaic of this lovely couple made with the C8 and the 350D. The shot has been taken in bad weather so it took 4 nights to collect a very unimpressive total of 53X8' sub-exposures. In spite of the relatively short integration time, the result is reasonably decent.

NGC 3556 - M 108 (Ursa Major)

A shot with the ASA astrograph

NGC 3556 - M 108 (Ursa Major)

In this wide field image the galaxy M108 is accompanied by the planetary nebula M97 (left). 31X8' over 4 hours of exposure, iso 800. Offset, dark, flat, hyperbolic sine stretch to maximize differences in colour. Final levels and unsharp masking in Photoshop CS. Canon 350D, M 80, f 6.0. Published on the July 2006 issue of "Le Stelle".

NGC 3992 - M 109 (Ursa Major)

A marvellous prototype of the theta barred spirals (8.3'X4.6'). Notice the blue knots in the spiral arms and the much redder bar. In the larger image at least four more galaxies are easily visible arranged in a line crossing diagonally the frame from the upper left corner. PGC 37700, mag 15.2, 1.6'X0.5'; not identified; PGC 37621, mag 16.8,1.0'X0.1'; PGC 37553, mag 13.8, 2.0'X0.8'.

I am quite fond of this picture, since it has been my first (relatively) successful attempt at autoguiding. At that time, 4 hours of exposure 31X8' seemed like an unbelievable feat! Offset, dark, flat, hyperbolic sine stretch to maximize differences in colour. Final levels and unsharp masking in Photoshop CS. A tiny satellite trail crosses the field. Canon 300D, C8 f 6.3.  Published on the July 2005 issue of "Le Stelle".

NGC 5457 - M 101 (Ursa Major)

A great spiral (28'X21') 25 M light years from us. ASA astrograph and the STL11000 camera. 13 hours in 4 nights. For the archaeologists there are two more versions available. Canon 350D, C8 f 6.3; 62X8' in three nights.  Canon 300D, C8 f 6.3; 35X8'.

NGC 4258 - M 106 (Canes Venatici)

Canes Venatici is a very inconspicuous constellation that harbours some marvellous and complex galaxies. The first we meet is a barred spiral (19'X8') 21-25 M light years from us. The high resolution image shows well the bright blue knot of your hot supergiants together with the red spots of the HII emission nebula. The galaxy has been catalogued in the Seyfert catalogue of active galaxies and the nucleus hosts a powerful maser.

Canon 350D, C8 f 6.3, iso 800. 55x8' collected in four night (7, 13, 18 May, 2007). Calibration, gradient subtraction and color balancing under Iris. I computed two different hyperbolic sine stretching for the stars and central part of the galaxy and for the external arms. The two layers have been blended in Photoshop. Wavelet filtering and noise control in PixInsight.

NGC 4631 - NGC 4627 - NGC 4656 (Canes Venatici)

ASA 10", f3.6 STL 11000. Pure RGB composite, 11x8' per channel.

NGC 4736 - M 94 (Canes Venatici)

Second of the series we meet one of the oddest galaxy of all. M94 is an Sab spiral with a very bright central part surrounded by a faint ring (13'X7')

Canon 350D, C8 f 6.3, iso 800. 60x8' collected in three nights. Wavelet filtering on the central part of the galaxy to enhance the extraordinaire details of the dust lanes.

NGC 5055 - M 63 (Canes Venatici)

Next, and only a few degree apart from M94, is an extraordinaire spiral (13'X7') 25 M light years from us. This tight galaxy has a multitude of tightly wound spiral arms  interlaced by several HII regions divided by dark nebulae. A large and peculiar dust lane seems to delineated the south edge of the galaxy.

This picture has been a large effort: I collected 46X8' subexposure (over 6 hr of total integration time!) in three different nights under a very lousy mag 3.5 sky. Canon 300D, C8 f 6.3, iso 400. Processing has been a long affair and was optimized to extract the spatial structure of the spiral arms.

NGC 5194 - M 51 NGC 5195 (Canes Venatici)

A great grand design spiral (9.0'X7.5') 25 M light years from us. The spiral arms are interlaced by several HII regions shining in bright blue-green light. 5' to the north the peculiar galaxy  NGC 5195 (7.0'X5.0').

This image is the result of the summation of three different data sets acquired in the span of a year. The datasets rather different characteristics, so each has contributed to the final image through appropriate spatial and chromatic filtering.

All the datasets have been acquired at the f6.3 focus of a Celestron 8. Datasets: a) Canon 300D 30X8', iso 400. March 5-6, 2005. b) Modified Canon 350D 28X8', iso 800. February 5-6, 2006. c) Modified Canon 350D 24X8', iso 400. May 5-6, 2006. The first version of this image was published on the July 2005 issue of "Le Stelle".

NGC 5371 and Hickson 68 (Canes Venatici)

7.6 degrees west of g Bootis there is this lovely group of galaxies. On the left the nice barred spiral NGC 5371 (4.2'x3.4') is physically unrelated to the group of galaxies on the right, catalogued as the entry 68 of the Hickson catalogue of compact galaxy group. NGC 5350 (3.2'x2.3') is the most appariscent member of this group, exhibiting a marvelously complex barred spiral. NGC 5354 (S0, 1.4'x1.3') and  NGC 5353 (S0, 2.2'x1.1') are immediately to the south and they are surrounded by a common envelope, better seen in a BW and stretched image. Further south there is the unrelated and very blue barred spiral UGC 8841. One feature of this field that attracted my attention, is the lovely colour contrast between the brightest stars in the field, with spectral types ranging from the very red K5 to the blue A2. Click here for a full scale wide field image of the area.

ASA 10", f3.6 STL 11000. LRGB composite, bin 1 for all channels. Luminance: 26x8'; RGB: 24x8' per channel. Three nights of acqisition, in total.

NGC 5907 - (Draco)

A beautiful  side-on galaxy in Draco. This is a spiral (type Sc)  almost perfectly aligned on its plane. Notice the yellow bulge at the centre, separated from the bluer edges of the spiral arms by dust lanes .

Modified Canon 350D, C8 f 6.3, iso 800. 15X8' subexposures.  10 iterations of Richardson-Lucy deconvolution on the luminance channel. April 8, 2006.

NGC 6946 - (Cepheus)

11.5'x9.8', M 9.0, SBc) NGC 6946 is both a spectacular and dim galaxy in Cepheus. At a distance of between 10 and 20 million light years, this galaxy is one of about a dozen nearby neighbors to the Milky Way: unfortunately, it is highly obscured by interstellar matter of the Milky Way galaxy, as it is quite close to the galactic plane. This galaxy has had eight supernovae in 60 years: 1917, 1939, 1948, 1968, 1969, 1980, 2002, and 2004. This galaxy holds another record: it experiences a much higher rate of star formation than all the large galaxies in our local neighborhood. This production of new stars  eventually leads to accelerated numbers of supernova explosions.

Modified Canon 350D, C8 f 6.3, iso 800. 35X8' sub exposures in two nights. April 25-28, 2006. Click here for a wider field image of the area.