Meade Deep Sky Imager - Gallery 6

Some objects taken in November-December 2005

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José R. Torres

This page shows the last results obtained in December 2005. I have had very scarce opportunities to observe. For some months, work reasons have prevented me even to take a rest looking at the sky, and this situation will still last some more months, perhaps up to half 2006. My programming project CNebulaX is frozen as well.

Some weeks before, the LX200 electronics behaved abnormally and I was afraid the telescope had got a severe breakdown; I had to go home very worried. However, the tests performed at home did not found any trace of failure, so I tried once more and I was lucky. I still think that the electrical connections are not in completely well; perhaps the plug is failing. The night was pretty good although moisture was present, and ended covering with dew the correcting plate. I used a hairdryer to remove the dew; the heat, however, affected the optical performance, and for more than an hour the image was blurred and the stellar definition was deteriorated.

This time I have learned some image processing techniques. Indeed, the images in previous sessions had a hidden potential that I was not able to exploit properly. I have leaned better techniques, got new software, and reprocessed some of them. The changes are spectacular; some previous images now show a rather more pleasant appearance (have a look to the Trifid nebula, the Omega Nebula and the Dumbell Nebula, for instance).

	NGC 1952 / M1 / Crab Nebula 05 34.5 +22 01 Tau SNREM:8.4m/8'X4'/130*/vB,vL,E135,vglbM,r RosseSawFilaments;centPulsar16Mag;3C144 135u1/77u2/5s/158-1m/35HBc This is a first colour-corrected image (considering the limitations of the DSI) from a IR‑biased image, showing the filamentary structure of ionized hydrogen. It averages 20 images of 42 seconds each. The colours can be recovered (to a certain extent) trying to fit the histograms of each colour channel within a small background area, up to get a white appearance, but I still need more practice to get good results. This white balance can be equally done with processing software such as MaximDL, PixInsight or Photoshop. The corrections, however, cannot be well applied in the presence of dew on the correcting plate, since dew biases the colours to magenta and removes the blue and green channels.
	NGC 5194 / M51 / Whirlpool Galaxy 13 29.9 +47 12 CVn GALXY:Sbc/8.4m/10.8'X6.6'/163ºAP !!!,Greatspiral/interactingPair;classicSpiral 76u1/37u2/7s/589-2m/11HBc M 51 again, to check the learning curve. This is a single image with a longer combined exposure (15x42s), which can be compared with this old image. The current one has got a galaxy with details pleasantly soft and a good star definition. The colours, so biased in the former image that seemed inexistent, are now rather well recovered. The difference is essentially the image processing techniques applied. By the way, two satellite trails (one of them very intense) were registered in the original image, just when I was thinking to stop the exposure (Murphy's law). Fortunately, I could remove them by cloning adjacent pixels, so virtually only a small trace remains in the final image (bright star just to the upper right).
	NGC 1976 / M42 / Great Orion Nebula 5 35.3 -05 23 ORI CL+NB 4m/90/E+R/BCHM:M/Trapezium*6.7-7.7m; >50var*invl; M43toNE!!!,TheOri 225u1/116u2/11s/278-1m/53HBc The Great Orion Nebula, combining two images: 17x30s (outer area) and 30x6s (core). I still need more practice fusing images, because the colours are biased in the left transition area, but the image is rather close to the visual appearance. Anyway, I think it is a very good starting point, and I hope to use the raw images to learn combination techniques. The inner area was level stretched and feathered to fuse on the other image (technique explained in the Jerry Lodriguss book "Photoshop for astrophotographers). This object presents a so wide dynamic range that is absolutely impossible to stand out the delicate external structures without burning the trapezium region, so the only solution is compose images.
	NGC 3031 / M81 9 55.6 +69 04 UMA GALXY:Sb/6.9m/24.9'X11.5'/157ºAP !eB,eL,E156, gsvmbM,BN,brightestInGroup;fineSpiral 23u1/14u2/2s/538-2m/14HBc The first M 81 image, taken on Feb 12th, got disappointing results: a plain galaxy with no structure, just a fuzzed core. I suspected that this time, with the F:3.3 focal reducer and extending the exposure, I had to get a good image, but I am surprised: the results are much better than those I hoped to get. This image is again the combination of a short exposure (3x21s) and longer one (9x42s), just to show the inner stars. The spiral structure is now evident, and some condensation (blue) and nebular complex (red) could be registered. The inner red / blue area is an artefact owing to an imperfect blending of the short and long exposures.
	NGC 3034 / M82 9 55.9 +69 41 UMA GALXY:Sd 8.4m/10.5'X5.1'/65ºAP, vB,vL,vmE(ray),M81Group 23u1/14u2/2s/538-2m/14HBc Good image (12x21s) although slightly less detailed than at F:D 6.3 (see former image here). The stars are slightly out of focus. The image quality was deteriorated after removing the dew off the correcting plate with a hairdryer (see Abell 10 below)
	NGC 57 / NGC 6720 / The Ring Nebula 18 53.6 +33 02 LYR PLNNB:4(3)/9.4m central*Var14To16Mag;PK63+13.1 117u1/49u2/8s/1153-3m/25HBc This is an old image taken last summer, but not included in the image logbook. It was a short exposure (17x6 sec), that was discarded. However, the results attained after reprocessing other objects encouraged me to try this image. The exposure is perhaps too short but the nebula shows all the usual details that can be seen in good M57 pictures, even a remarkably violet central star and a second red star within the central depleted area. So one of the discarded images has become in my best M 57 picture up to the moment.
	NGC 2024 / Ced 55p / Tank Track Nebula 5 41.7 -01 51 ORI BRTNB:E 30'X30',!irr,B,vvL,blackspincl, brightButMaskedByGlowOfZetaOri 226u1/116u2/11s/253-1m/53HBc This is the "Flame Nebula", the emission complex north-west Alnitak, or z (zeta) Orionis. This nebula is not difficult to see and responds very well to nebular filters (OIII or UHC). The huge dark mass splitting it north-south is rather easy to glimpse, although the details are never as evident as in this picture. The only problem is the glare of Alnitak, which is the ioinization source disturbing strongly, but that can be easily removed out of the field (20'). This image integrates 15x30s exposures.
	NGC 2403 / UGC 3918 7 36.9 +65 36 CAM GALXY:SBc 8.5m/23.4'X11.8'/127ºAP/!!cB,eL,vmE,vgmbMN HV44;inM81Group;manyWellResIrregArms;broadBar 21u1/15u2/1s/25-1m/15HBc The forgotten galaxy, which deserved being included in the Messier Catalogue. It is very bright although excessively diffuse. The spiral arms, which seem fade on the background, can be traced up to make the galaxy two times larger. The galaxy is very irregular at the eye, mottled, and the spiral arms can be glimpsed with medium-sized telescopes. The picture shows nebular regions, reaching the outer regions apparently beyond the galaxy limits, and a single asymmetrical inner arm. There is no evidence of the second arm that some reports indicate in an opposite situation (180º). This image integrates 12x42s exposures.
	Abell 24 / PK 217+14.1 7 51.6 +03 00 CMI PLNNB:4(3)/13.6m 230u1/114u2/12s/223-1m/51HBc A ghost haze measuring 4'x3', located 4º SW Procyon, a CMi. I have never tried it visually because the figures suggest that this object is usually beyond the capabilities of the eye with a 10" telescope, although it is accessible under very good skies at minimal magnification. The image integrates 12x42s exposures and registers Abell 24 as a annular nebular with some overlaid stars, corresponding to a highly evolved object in terminal stages. It was not as difficult as one could expect. The central star should be one of the three stars forming a tiny triangle (17.2 m).
	Baade 1 / PK 171-25.1 3 53.5 +19 28 TAU PLNNB:4/13.9m 132u1/78u2/11s/187-1m/36HBc My particularly challenging planetary nebula. To my knowledge, Baade 1 is the only planetary nebula whose photographic magnitude (13.9) is brighter than the visual magnitude (15.8!!!). The central star is 17.1 magnitude. I have only seen it once with a 310 mm Newtonian telescope. I got a first image some sessions ago, and in the last one I had tracking: it failed. This time, the nebula is rather clear, and even the central star can be weakly seen. I even dare to say that the annular structure is faintly perceptible, darker in the core. Another very faint star in contact can also be seen to the right. This image integrates 12x42s exposures.
	Abell 10 / PK 197-14.1 5 31.8 +06 56 ORI PLNNB:3/12.7m/34" 180u1/96u2/11s/230-1m/53HBc This 18x42s image was the last taken before noticing that the correcting plate was covered with dew. For this reason, the image is mainly magenta (IR is better transmitted in the presence of dew), with few or no information in the green and blue channels. Another image spared owing to dew was a shot taken to Palomar 2 (not included here). I removed the dew with a hairdryer, but, although the dew disappeared, the heating affected the telescope performance, and for more than an hour, the image quality was deteriorated. It is surprising, taking into account the amount of dew deposited, that I could image Abell 10. I think that the star limiting magnitude in the picture is still as high as 15.5-16.0, in spite of the dew. The planetary nebula, however, is a rather faint object for those conditions, and green-blue colours are more affected with dew.
	Abell 12 / PK 198-6.1 6 02.4 +09 39 ORI PLNNB:13.9m OnNWEdgeOFMuOri;starMakesIDDifficult 181u1/96u2/11s/204-1m/52HBc A planetary nebula very close to the white star m Orionis (4.1 magnitude), which strongly disturb its perception since it lies only 1.2' from the nebula. Owing to these terrific figures, I have never tried to see the nebula visually. Only huge telescopes (17") provided of nebular filters to both enhance the nebula and remove brightness to m Ori have succeeded in this observation. The nebula seems to be rather green, so I will try it with OIII or UHC next time I enjow truly good skies, although the glare of m Ori is sure that will make it extremely difficult.
	NGC 2362 / OCL 633 / Tau CMa cluster 7 18.7 -24 57 CMA OPNCL:I3pn 4.1m/8.0'/60* Cl,pL,Ri,(30CMA) HVII17;40*To13m 319u1/154u2/19s/345-1m/70HBc This is one of the youngest open clusters, a rich aggregation of white bright stars surrounding the blue star Tau Canis Majoris (4.4 mv), in a triangular-shaped arrangement. NGC 2362 can be seen with bare binoculars and it is always spectacular through any instrument and practically under any sky condition, particularly at low magnification. In the image, the low altitude above the horizon spared the star definition and introduced seeing effects. Tau CMa is surrounded by a pink halo and LR deconvolution intensified this effect. The same Tau, which is a physical member, is also a multiple star.