26 February – blog 4 of 4
Crisp winter skies. It was going to be a cold one. The zodiacal light put up a great show again and this night I had cameras set up to capture it.
In the final stretch of evening astronomical twilight I logged eleven more Struve double stars in Orion. Three of these were real showpieces: STF688, STF701 and STF708. For all three it was the color of the secondary that made the difference. The observation of the last one of these, STF708, was all the better with bright white Psi-1 Orionis sharing the field of view.
STF688AB split. The PA is just a little smaller than 90° (95° in WDS2021.12). A beautiful double.A is white-yellow, B is yellow, the color of B is clearly much deeper than that of A.1/2 FoV to the ESE is a mag. 10.5 star with a mag. 12 star to its SSW, ±185°/50″, and a mag. 12 star to its ENE, ±070°/80″ (not a double star in WDS).STF701AB split. A very beautiful double.A is bright white, B is grey-blueish, a subtle blueish hue.STF708AB split. A beautiful double.A is bright white, B is light blue, a distinct color and clearly contrasting.Just over 1/4 FoV to the SW is the bright white mag. 3 star Psi-1 Orionis.
First deepsky objects of the session, a selection of nebulae in Taurus, away from the pillar of light extending from the western horizon.
Six observed, two of which have a name: NGC1555 – “Hind’s Variable Nebula” and IC2087 – the “Little Flame Nebula”.
Hind’s Variable Nebula was a tough one, only visible with use of averted vision but clearly an elongated nebula. Nearby star T Tauri appeared pale orange even when shining at only mag. 10.5 and was clearly contrasting with the white mag. 9 star to the southwest.
Only visible with use of AV, difficult to observe, a very faint but clearly NNW-SSE elongated glow, approximately 20″ WSW of the pale orange mag. 10.5 star T Tauri.1/4 FoV to the SW is a pale white mag. 9 star (component A of the double star Burnham 9004).
The Little Flame Nebula was hardly any easier, at the limit of visibility without averted vision.
An extremely faint, shapeless glow, not very small. Only clear with use of AV.1/3 FoV to the SSE is a mag. 10.5 star with a mag. 12.5 star to its NNW (not a double star in WDS).
In Auriga I stopped by one of Astrotreff’s Objects of the Month for January 2022: Vorontsov-Vel’yaminov 1150. As was to be expected, only the larger galaxy MCG+08-11-011 was visible.
Only the larger eastern galaxy MCG+08-11-011 (PGC18078) is visible, the small western galaxy 2MASX J05544749+4626117 is not visible. A clearly north-south elongated streak, more elongated with AV and slightly brighter in the middle with a very bright nucleus that is very clearly visible without AV. The nucleus resembles a mag. 12 star. The superimposed star 4UCAC683-041988 to the NE of the center is not visible. The galaxy is not bright but the shape is notable.
Nearby, I observed the even fainter group Vorontsov-Vel’yaminov 1149 that is accompanied by the double star Espin 1321 and, half a degree southeast of Vorontsov-Vel’yaminov 1150, Auriga’s brightest planetary nebula IC2149.
With the filter slider now a part of the optical train of my scope, planetaries in Monoceros were next. Like so many of the clusters in the unicorn I observed in the two preceding sessions, all but one of these were first time observations.
The “Red Rectangle” is a protoplanetary nebula surrounding the distinctly orange colored star V777 Monocerotis. At a lower magnification the nebulosity was only discernible with use of filters. The more magnification I applied, the more obvious the elongated nebulous shape became. Unfiltered, it appeared ruddy to me, but that may be due to the color of the star playing tricks on my eye. At the highest magnification the nebula seemed brighter on the western side and fainter east-northeast of the middle. What appeared to be knot just came into view on the south-southwestern edge, but I suspect that to be a faint field star.
17mm Nagler T4: A pale orange mag. 9 star (V777 Monocerotis), quite a distinct orange hue, but no nebulosity is visible.17mm Nagler T4, Lumicon UHC: Using this filter the star V777 Monocerotis remains visible, with AV a subtly north-south elongated shape is visible.17mm Nagler T4, Lumicon OIII: Using this filter the shape is elongated NNW to SSE, visible without AV. Thereby the shape of the nebula is discernible. The star V777 Monocerotis remains notably bright with use of this filter.12mm Nagler T4 & 12mm Nagler T4, Lumicon UHC / OIII: As with 17mm. Unfiltered the nebula appears a bit ruddy but that is suspected to be due to the color of the star V777 Monocerotis.7mm Nagler T6: Using this magnification and AV the nebula is clearly elongated NNW to SSW.7mm Nagler T6, Lumicon UHC: Using this filter the nebula is elongated without use of AV and is subtly brighter in the middle.7mm Nagler T6, Lumicon OIII: The effect of this filter is comparable to that of the UHC filter but is more suble. The nebula is slightly less elongated.3.5mm Nagler T6: Using this magnification the elongated shape of the nebula is discernible.3.5mm Nagler T6, Lumicon UHC: Using this filter and AV the elongated shape is clear and the nebula is fainter to the ENE of the middle. There appears to be a knot on the SSW edge, which is notable.3.5mm Nagler T6, Lumicon OIII: As with 3.5mm and the UHC filter the elongated shape of the nebula is clear and the nebula is fainter to the ENE of the middle. It is clear, too, that the nebula is slightly brighter on the western side in an elongated part aligned NNE to SSW. The suspected knot on the SSW that was visible with use of the UHC filter, is clearer with use of this filter.A remarkable object.Working out the observation I determined that the knot on the SSW edge is likely to be a faint star.
Minkowski 1-8 & 1-9, Stephenson 3-1 and Minkowski 3-3 & 1-16 are all very small, but none are stellar with use of filters, higher magnifications and/or averted vision.
NGC2346, the “Butterfly Wing Nebula” is a beauty. The fainter outer regions were visible on both sides of the elongated and brighter center. Filters made it even better, especially when using OIII.
17mm Nagler T4: Quite bright, without AV a round glow surrounding a mag. 10.5 star. With AV the nebula is gradually brighter in the middle, centrally slightly elongated ENE to WSW in a more evenly bright part and the outer regions of the nebula are visible NNW and SSE of the middle. A beautiful nebula.17mm Nagler T4, Lumicon UHC: Using this filter the nebula is larger and the brighter central part is notable, especially with use of AV. The outer parts of the nebula towards the NNW and SSE are clearer, too.17mm Nagler T4, Lumicon OIII: This filter has a comparable but slightly stronger effect than the UHC filter has.12mm Nagler T4: As with 17mm.12mm Nagler T4, Lumicon UHC: Using this magnification and this filter the outer parts of the nebula clearly brighten with AV which gives the nebula a more round shape overall.12mm Nagler T4, Lumicon OIII: Using this magnification and this filter the nebula is more even in brightness without AV, with AV the outer regions of the nebula brighten even more than with use of the UHC filter. With AV the outer parts of the nebula towards the NNW are slightly larger than they are towards the SSE (extending slightly more) and the transition to the fainter outer parts is more sudden. A remarkable object.
With the skies perfectly clear and quite steady, I made yet another attempt at two very faint planetaries in Canis Minor and Lynx: Abell 24 and the “Headphone Nebula” (Jones-Emberson 1). I have tried to observe these nebulae a great many times, but never succeeded. This night, that changed.
Abell 24 in the little dog required filters to reveal any nebulosity at all. With use of a UHC filter the nebula’s southwestern and northeastern brighter lobes we visible, using the OIII filter the eastern part remained out of sight.
17mm Nagler T4: Unfiltered the nebula is not visible.17mm Nagler T4, Lumicon UHC: Using this filter only the brightest SW and NE part of the nebula are visible, very faintly. The SW part is slightly larger than the NE part is, the ENE part is slightly elongated north to south.17mm Nagler T4, Lumicon OIII: Using this filter and AV the western part of the nebula is visible, the eastern part is not visible. Without AV the nebula is not visible.
In Lynx, the Headphone’s lobes were brighter, but only just so. As was the case for Abell 24, the fainter regions of the nebula were not observed.
17mm Nagler T4: Unfiltered the slightly NW-SE elongated glow of the NW part of the nebula is visible, very faintly. In that glow is a mag. 12 star, to the WNW thereof, just detached from the glow is a mag. 13 star, twice that distance towards the ENE, also detached from the glow, is another mag. 13 star.To the SE a narrower, SW-NE elongated part is visible that is slightly brighter and slightly more elongated than the NW part is.17mm Nagler T4, Lumicon UHC: This filter has a good effect, the NW part of the nebula is larger and brighter on the SW side in a SW-NE elongated part and the SE part is more bulging SE to NW. The SE part is longer NE to SW compared to the NW part of the nebula. Only these lobes of the nebula are visible. The fainter outer parts of the nebula on the SW and NE side are not visible.17mm Nagler T4, Lumicon OIII: The effect of this filter is comparable to that of the UHC filter, the effect of the UHC filter is slightly better. Using this filter it can not be discerned that the SE part of the nebula is slightly more bulging, which was visible with use of the UHC filter.
With the temperature now well below freezing, I took a break for some hot tea before returning to Hydra for the galaxies in CSOG’s 12-14″ Gx-2 guide.
The first galaxy of the 34 observed in Hydra was above average. NGC2555 is Holmberg 95A while members B & C are superimposed stars. Both stars were visible.
A relatively bright, NE-SW elongated glow, gradually brighter in the middle, with AV the nucleus is faintly visible. Without AV a mag. 14 star is visible on the NW edge and a mag. 14.5 star on the NNW edge. These stars form Holmberg 95B & C, respectively.
NGC2615 revealed subtle irregular structure, but no superimposed stars.
Small and faint MCG-01-22-032 (PGC24353) is nothing special, no more than a glow that is subtly brighter in the middle, lacking a nucleus. But it was the much brighter glow in the field of view, to the south-southeast, that caught my eye: PGC153039. A remarkably bright galaxy (well, relatively speaking) for one that only carries a 6 digit PGC designation. In the image below it is visible at bottom left. This galaxy was not included in CSOG, but will be in the next edition. It just shows what remains to be observed off the beaten path, even when using only moderately large amateur telescopes.
Surprisingly, too, the notably close pair of stars to the southwest of MCG-01-22-032 (at bottom right of the galaxy in the image below) is not included as a double in the WDS catalog.
MCG-01-22-032A very small, faint, round glow, even in brightness. With AV subtly brighter in the middle, no nucleus visible.Directly north is a mag. 11.5 star, 1/3 FoV to the SW is a white-yellow mag. 10.5 star (SAO136136) with a faint but yellowish mag. 11 star to its NNE (not a double star in WDS). 1/2 FoV to the SSE is the galaxy PGC153039.PGC153039Observed simultaneously with the galaxy MCG-01-22-032 (PGC24353), 1/2 FoV to the NNW: Quite a bright, east-west elongated, oval glow, not very small, even in brightness without AV. With AV slightly more round and subtly brighter in the middle, no nucleus visible. Remarkably bright for a galaxy with only a six digit PGC designation.Directly NE is a mag. 12.5 star.
The elongated core of NGC2642 was notable, along with irregular structure in the outer regions of the galaxy, but no arms.
An irregularly round glow with irregular structure, gradually brighter the middle. With AV brighter in a NW-SE elongated core, which is notable, with AV the outer parts of the galaxy to the NNE and the SSW of the core are visible, the NNE outer part is slightly brighter than the SSW part is, but no arms are discernible. To the SE of the middle is a mag. 12.5 star (4UCAC430-046940), slightly farther to the NNE of the middle is a mag. 14 star (4UCAC430-046941),To the south is a slightly elongated triangle of mag. 7.5 and fainter stars pointing NW. The faint galaxies SDSS J084035.15-040926.8 & SDSS J084034.11-040932.6 to the WNW of the tip of the triangle are not visible.
NGC2876 gave away some of its irregularity with use of averted vision, as the bright core was clearly offset.
An east-west elongated glow, suddenly brighter in a core that is slightly elongated in the same direction with quite a bright nucleus that is visible without AV. With AV the core of the galaxy is even more suddenly brighter. The dark part on the NNW side can not be discerned, but with AV it is clear that the brighter core is to the east of the middle of the galaxy and with AV the WNW outer, elongated part of the galaxy is faintly visible, which is notable. On the east side the galaxy ends more suddenly.To the NNW is a small, faint, round glow, even in brightness without AV, with AV gradually brighter in the middle, no nucleus visible (galaxy MCG+01-24-017 / PGC26718). 1/4 FoV to the south is the galaxy IC2471, 1/2 FoV to the east is the double star Skiff 787.
Easily the best in this selection of galaxies in Hydra was the group Hickson 40 a.k.a. Arp 321 / Vorontsov-Vel’yaminov 116 / White 11. The sixth member of this group, Hickson 40F, is actually a star. I was able to observe 4 of the 5 galaxies + the star.
17mm Nagler T4:A – MCG-01-25-009 (PGC27509) is a round glow, even in brightness with a bright nucleus that is visible without AV, with AV slightly elongated north to south and quite suddenly brighter in a round core. To the south is C – MCG-01-25-008.B – MCG-01-25-012 (PGC27513) is a round glow, gradually brighter in the middle, with AV the nucleus is faintly visible.C – MCG-01-25-008 (PGC27508) is a clearly NW-SE elongated glow, slightly larger but just a little fainter than D – MCG-01-25-011 is. To the SE is B – MCG-01-25-012.D – MCG-01-25-011 (PGC27516) is the NNE galaxy, a NE-SW elongated glow, even in brightness, no detail visible, slightly brighter than C – MCG-01-25-008 is. Directly SE is a mag. 14 star (4UCAC426-051758), that star is Hickson 40F. To the SW is A – MCG-01-25-009.E – MCG-01-25-010 (PGC27515) is not visible.A nice group.12mm Nagler T4:Using this magnification C – MCG+01-25-008 is difficult to observe, E – MCG-01-25-010 that is perpendicular to C – MCG-01-25-008 is not visible. B – MCG-01-25-012 is clearer with use of this magnfication.
A longer break for more hot tea and soup, as the cold was starting to get to me, before heading to Sextans for more galaxies. Using CSOG’s 12-14″ Gx-2 guide for the constellation.
The first galaxy in Sextans, the elliptical NGC2974, was the brightest one observed. It appeared slightly irregular in the core and the orange star that is superimposed over the southwestern edge enhanced the overall appearance.
A NE-SW elongated, oval glow, quite suddenly brighter in a small, round core. On the SW edge is an orange mag. 9 star (SD-03 02751). With AV the core is slightly elongated in the same direction with notable, irregular structure and is brightest on the SW side. A nice galaxy.
Local Group galaxy MCG-01-26-030 (PGC29653) a.k.a. Sextans A contains two bright star clouds. The southeastern of the two, that goes by Billet, Hunter, Elmegreen Sextans A 2, was visible, to the south-southeast of the mag 10.5 star that is superimposed over the east-northeastern edge of the galaxy.
An extremely faint, irregularly round glow with a mag. 10.5 star on the ENE edge (TYC4907-00713-1). The galaxy is subtly brighter to the SSE of the mag. 10.5 star, that’s the star cloud Billet, Hunter, Elmegreen Sextans A 2, with AV it is clearly visible as a round, brighter part. The galaxy is quite suddenly fainter on the north side (to the NW of the mag. 10.5 star) and gradually fainter towards the SW.To the WNW, just detached from the glow of the galaxy is a mag. 13.5 star. The star cloud Billet, Hunter, Elmegreen Sextans A 1 to the SE of that star, on the western edge of the galaxy, is not visible.
The final galaxy in Sextans, IC651, although small and faint did reveal subtle detail. I could not distinguish its arms but it did appear irregular with use of averted vision, brighter in north-northwest to south-southeast slightly elongated part that made the nucleus appear to be just southeast of the middle.
A round glow, quite suddenly brighter in the middle. Slightly irregular with AV, with AV it is clear that the galaxy is brighter in a slightly NNE-SSE elongated part and the nucleus is visible that is slightly SE of the middle, which is notable. The arms of the galaxy can not be discerned.
Almost five and a half hours into the session, I ended with an observation of the large asterism the 41 Sextantis group. By this time, the temperature had dropped to -6°C. A bit too frosty to be outside any longer, but the skies that came with it were the reason I was already looking forward to my next trip to the Alps.
Observations
17 double stars6 nebulae10 planetary nebulae75 galaxies and galaxy groups1 star cloud1 asterismTotal: 110 observationsFirst time observations: 101 objects
Details of the objects observed in this session are in the table below.
click here for my observing log
to top of table
Observations astrotrip Cornillac, winter 2022
Four nights under the stars for a tally of 406 observations, 355 of them first time observations.
64 double stars60 open clusters3 globular clusters31 nebulae1 dark nebula10 planetary nebulae234 galaxies and galaxy groups3 other
