Monday, November 18, 2013

2013 Deep South Regional Stargaze

 
In spite of rainy and windy weather, the 2013 Deep South Regional Stargaze had two nights of good weather which allowed good views of deep sky objects. Unfortunately, I was only able to stay Friday night due to work considerations. Nevertheless, I made good use of the time spent there to observe deep sky objects.
NGC-7094 is a very faint planetary nebula in Pegasus that eluded me from my usual local observing sites. At 227X, it still required an O-III nebula filter to be certain that I had indeed found this slightly oval planetary nebula. This object has two brighter regions along the rim, as well as a prominent central star.
NGC-7437 is one of many fainter galaxies in Pegasus, and until now eluded me from the locally light polluted skies. Small, round and faint, NGC-7437 displays little structure other than a weak central brightening and spans 1.8 arc-minutes. This face-on system has a classification of type Sc which is consistent with the very weak central core, and a magnitude of 13.4, which explains why it was as tough to see locally.
NGC-7538 is a small emission nebula in Cepheus. Quite small, it is also quite bright with a pair of stars inside it. Nicely visible without a nebula filter, an O-III filter greatly improved the view. The nebula's irregular outline and woolly appearance belies it's nature as a cloud of very hot, ionized gasses. Spanning some 8 by 7 arc-minutes, it is certainly with range of much smaller telescopes than a `15-inch.
The galaxies NGC-7463, NGC-7464 and NGC-7465 form a compact trio accessible to medium and large aperture telescope. NGC-7463 is a spiral galaxy of type SBb peculiar with a magnitude of 12.7. It is the largest of the three. NGC 7464 is an elliptical galaxy and the faintest of the three at magnitude 13.4. NGC-7465 is a SBO barred spiral galaxy with an apparent magnitude of 12.4 and the brightest member of this galaxy trio. 
This is a nearly edge-on, very elongated galaxy that resembles a large, ghostly cigar at 227X. NGC-7497 is some five arc-minutes in length and shines with a magnitude of 12.4, and yet appears nearly as faint as NGC-7437. It's pointed northeast to southwest in the sky with a fairly strong central brightening. This galaxy like NGC-7437 is also a Sc spiral galaxy but because of the brighter magnitude and near edge on orientation, was easier to spot.
 
Unfortunately the skies gave out at 2:30 and observing came to an end. I covered the mirror and went to the cottage for the rest of the night. After eating breakfast next morning, I packed up the telescope and returned home. Turnout was quite good given the bad weather Wednesday and Thursday, which I had hopes to also make use of. Once again, the weather was a disappointment like last year. I was hoping for more than one night of good skies, and since I had to return home Saturday which led to me missing the good weather that night. Nevertheless, I had an opportunity to see objects I could not from my usual observing sites. I'm probably going to try enrolling in the annual Spring Scrimmage at the same site so I can observe spring and summer objects before the haze and murky skies close in next year.
 

Wednesday, October 23, 2013

Summer and fall galaxies

The long awaited fall transition to cooler and clearer weather has begun for my area. The skies are not only clearer and darker, the nights are longer and the bugs no longer lurk as massive swarms in the darkness to feast upon stargazers. Last week a night came along that made going to a darker site more than worthwhile, so drove out to the countryside with the 15-inch to observe objects along the summer Milky Way and to log previously never seen summer and fall galaxies and nebulae. When I wasn't observing from my usual darker site, I was observing deep sky objects from home when the moon was absent.
First among the objects I wanted to look over was the obscure but pleasing open cluster NGC-1027 in Cassiopeia. It was surprisingly apparent from home, so I sketched this one from the driveway. It's not one of the better know open clusters in Cassiopeia, but a nice object at 142X even though its stars were fairly scattered.
The summer constellation Lyra is not what many amateur astronomers regard as a region of the sky where one would find galaxies. However, a surprising number of them can be found in Lyra, NGC-6646 being among the brightest. Small, faint and round with a brighter center, this object has an apparent magnitude of about 13. Its small apparent size gives it enough surface brightness to show up in less than perfect skies through the 15-inch. This system is a Sa spiral resembling M-81 but face on and far more distant.
NGC-6745 is another Lyra galaxy known as the "Birdhead Galaxy" due to it's distorted and bizarre shape. It is in fact not a single galaxy at all, but three of them some 200 million light years away merging into a single, larger galaxy. Very small and faint, it responds well to high magnification. I found a 6.7mm Explore Scientific 82 degree eyepiece gave the best view at 298X, which enabled it to reveal itself amid the dense field stars of the Milky Way. Shining at 13th magnitude, it is in range of 10 or 12-inch telescopes from dark sites. I was surprised at how easy it was to find with my 15-inch from an area subject to considerable light pollution. To me it did look somewhat like a bird's head, or a scrawled letter L.
NGC-6871 is one of countless open clusters to be found in Cygnus. I have discovered though this large and scattered star cluster tends to hide in plain sight, until a photo showed where the central concentration is. Shining at a combined magnitude of 5.2 and spanning 20 arc-minutes, NGC-6871 is a fine object for small telescopes. As a bonus, there's numerous other open clusters and nebulae in the same area.
In addition to two Messier objects and two well known planetary nebulae, Aquarius is home to numerous galaxies. Most are faint but a few are bright enough for 8 or 10-inch telescopes from dark sites. NGC-7252 shines at  magnitude 11.7 and has a classification of SBO. It is also known as the Atoms for Peace Galaxy because of the filaments that extend from it in photos, resembling the international symbol for the atom. It has in fact recently merged with another galaxy. While I did not see the filaments, I did see a weak central core that is displaced to one side at 298X. Small and faint, it responds well to higher magnifications to bring it forth from the surrounding sky glow.
Yet another Aquarius galaxy is the type SBb barred spiral system NGC-7416. Shining at magnitude 12.4, this galaxy has a fairly high surface brightness due to it being nearly edge-on. I saw a distinct unevenness in it's brightness where the central bar and spiral arms were inside the rest of the disk. Like NGC-7252, this galaxy responds well to high magnifications.
NGC-7457 is one of a huge number of galaxies in reach of amateur telescopes in Pegasus, and one of the best. Shining at magnitude 11 with an oval disk some four arc-minutes long, this lenticular galaxy shows a very strong brightening towards the center. It is bright and relatively easy to locate, with little to no structure visible other than the increasing brightness towards the center and a bright nucleus.

Before clouds rolled in and I took the telescope down for the night, I stopped to look for the globular cluster G-1 in M-31, and took the time to look at the galaxy itself along with it's nearby neighbors M-32, M-33 and M-110. I did not see the globular cluster, but I did get a nice view of these galaxies along with other deep sky objects. I also managed to find the dim planetary nebula Abell 70. I am looking forward to this years Deep South Regional Stargaze, set to take place at the end of this month. I plan to bring the 15-inch there and pursue fainter objects I have not been able to find locally. I will be posting the sketches I make while at the DSRSG. The cooler fall weather will make sky conditions far better than they've been all summer long. It will be a nice short vacation for me.

Wednesday, September 4, 2013

Colliding Galaxies and Exploding Stars

While the summer weather along the Gulf Coast is usually bad for observing deep sky objects, last week conditions improved enough to make it worthwhile to drive to a darker site than my driveway. Before that a rare occurrence became visible to the unaided eye, a classical nova in the constellation Delphinus bright enough to be seen from a suburban area from the northern hemisphere. Two supernovae in nearby galaxies are also now visible to amateurs with modest telescopes from a reasonably dark site. And while Saturn edges ever nearer to the Sun, Venus, Jupiter and Mars are moving away from it into a good position to be observed from Earth. Uranus and Neptune are already well placed for observation as Comet C/2012S1 ISON continues it's approach towards the Sun ahead of perihelion in November of this year.
Nova Delphini 2013 burst onto the scene over two weeks ago, reaching fourth magnitude in less than two days. The system where the nova outburst originated normally is at 17th magnitude at best, giving this nova outburst a luminosity of at least 100,000 Suns from it's location some 10,000 light years away. It's rapid rise to peak brightness at first seemed to indicate this is a "fast nova," one that reaches maximum brightness rapidly then fades rapidly from view, but it is apparent that is not what this nova is. It is still at 7th magnitude and is fading relatively slowly, reddening as it dims. Located near the planetary nebula NGC-6905, my 10-inch showed both the nova and the nebula easily through my 10-inch with a 24mm ES 82 degree eyepiece. Through the 15-inch and the same eyepiece, both will still fit in the same field of view because the nova and nebula are about 45 arc-minutes apart. It appears to be a slow nova, which often fade, then brighten a second or even a third time before they finally begin returning to their normal state as a faint, very dense white hot star. Because there has been no outbursts from this star recorded previously, this is a classical nova that will not erupt again possibly for thousands or tens of thousands of years. Due to it's immense distance from the Sun, we are seeing an explosion that occurred some10,000 years ago. Click on the link below for more information on this nova. At any rate, this is an opportunity for amateurs to follow a bright nova as it returns to normal. When I first sighted it, the nova was a yellowish white in color, but by the time this drawing was made the yellow tint deepened. As it fades, it color will become more reddish due to strong emissions from ionized hydrogen.

Nova Delphini 2013 is not the only exploding star visible to amateur astronomers at the same time. In nearby Lacerta is the galaxy NGC-7250 where a former nova destroyed itself as a type 1A supernova designated as SN2013dy. Unlike Nova Delphini, this white dwarf accumulated so much matter from another star it could no longer support itself against its own gravity. It collapsed and a thermonuclear runaway started, consuming the entire star in seconds and blowing it apart. Normally NGC-7250 is of little interest, it is very small and clearly irregular through the 15-inch, but the supernova was obvious at one end of this elongated galaxy. I would say right now it has an apparent magnitude of about 14, it took verification with a higher power eyepiece and a finder chart to see that yes indeed I had found SN2013dy. It can be seen with an 10 or 12-inch telescope under a reasonably dark sky, even and 8-inch might reveal it. Unfortunately, cloudy weather prevented me from seeing it at peak brightness, I was only able to catch this one well into it's decline. Also visible is another type 1A supernova in the Pisces galaxy M-74, but I was not able to find the galaxy before the moon drowned it out. The supernova will however remain visible for quite some time because the galaxy is close to ours, giving amatuers more time to find it. Currently it's at mangitude 12.6, visible to a small telescope in the outskirts of M-74.
Draco hosts a large number of galaxies, most of them faint or very faint. NGC-5908 is not a particularly bright object, but it does have a high surface brightness and shows up readily in less than perfect skies. Shining at magnitude 11.9 and with an apparent size of 3 arc-minutes, this object shows a spindle like outline and a rapid brightening towards the center. This galaxy is oriented nearly north-south and is a spiral of type Sb, similar to Andromeda. It also makes a pair with the 12th magnitude barred spiral galaxy NGC-5905, which I did not see that night. Sky conditions were quite poor, it was possible I was looking right at it and missed it. This pair will be the subject of a repeat visit, and the bright galaxies M-102 and NGC-5907 lie nearby. In all, this region of sky offers one face-on barred spiral, two edge on spiral galaxies and a lenticular galaxy.
Also in Draco is the galaxy duo NGC-5963 and 5965, the brightest two members of a quartet of galaxies. Unfortunately I did not find the other two members NGC-5971 and 5969, both of which are near 15th magnitude. The sky conditions were simply too bright and milky for them to be visible, but I am sure they can be seen from a very dark area when the skies are clear and moonless. In contrast to the very small apparent size and extreme faintness of the other pair, NGG-5963 and 5965 are brighter and easy to see. They hardly need a 15-inch, indeed an 8-inch under good conditions will show them well from a good site. NGC-5963 is a 12th magnitude Sc spiral galaxy that is inclined, giving it an oval shape with a brighter center that is 3.3 arc-minutes long. NGC-5965 is an edge on Sb spiral galaxy with a bright nuclear bulge and hints of it's spiral structure evident at 227X. One edge of the nuclear bulge was sharp and straight, hinting at the dust lane most spiral galaxies have. It was subtly patchy and so was NGC-5963. NGC-5965 has a total magnitude of 12.6 and an apparent size of .7 X 5.2 arc-minutes, making it a flat galaxy.
Yet another rich hunting ground for galaxies is the constellation Serpens Caput. One of the better finds for modest telescopes under good skies are the merging galaxies NGC-5953 and 5954. While NGC-5953 is an oval SAp galaxy, NGC-5954 is a severely distorted star burst galaxy that resembles a seedpod in shape. NGC-5953 apparent size is 1.3 X 1.6 arc-minutes with a strong brightening towards the center. Overall the galaxy shines with a magnitude of 12. NGC-5954 has an apparent size of 1.3 by .6 arc-minutes and is pointing nearly due north-south on the sky, with an total magnitude of 11.6. Intense bursts of star formation are underway in this SAB peculiar galaxy with an evident bridge between the two visible in photos. The nuclear region is clearly displaced towards one end of NGG-5954. Visually I saw that the halos of one galaxy merged into the other's. Eventually these colliding galaxies will merge into a larger elliptical galaxy. Located nearby and visible in a low power eyepiece is the edge on galaxy NGC-5951. It is a very flat, faint galaxy I failed to find under the rather poor skies that night, but under good conditions it will appear with the other two galaxies through an 8 or 10-inch telescope. At 13th magnitude with an length of 3.5 arc-minutes, this galaxy is very ghostly due to a low surface brightness.That is why NGC-5951 is evidently quite inconspicuous, and worthy of another visit to the region when Serpens is in a favorable position for observation again. At present twilight will soon engulf Serpens, making observations of it's galaxies impossible until winter before dawn.
NGC-5962 is a rather faint oval galaxy with a weak central brightening. Shining at magnitude 11.7 and spanning 3 X 2.1 arc-minutes of sky, this Sc spiral does not show a prominent central core but does look slightly patchy in keeping with it's classification as a loose spiral galaxy. It did however stand up to high magnification well, a 6.7mm eyepiece yielded 298X which offered a nice view of this galaxy.
 
NGC-5970 is another Serpens galaxy visible in modest telescopes, indeed I have bagged this one with a 6-inch from the same site where I sketched it with my 15-inch. Like NGC-6962, this galaxy is also a spiral system but it is a barred spiral galaxy of type SBc with it's long axis aligned almost exactly due east to west. A little brighter at magnitude 11.4 and spanning 2.9 X 1.9 arc-minutes this oval galaxy also has a stronger central brightening than NGC-5962, and it too is also patchy. In photos it's outer spiral arms resemble those of M-63, the Sunflower Galaxy.
 
These drawings were made over two consecutive nights, but the objects shown here are not the only ones I paid a visit to. Other objects I visited are the globular clusters M-5, M-9, M-22, M-13, M-15, M-57, NGC-6723, and NCG-7006. I spent time examining the open clusters M-11, NGC-6520 and it's dark nebula Barnard 86, and NGC-6939. Other galaxies I observed but did not sketch were the Andromeda and Triangulum galaxies as well as Local Group members NGC-147, NGC-185, M-32 and M-110. The Cassiopeia galaxy NGC-278 and the Cepheus galaxy NGC-6946 were also observed. Other galaxies observed were Stephan's Quintet, NGC-7331 and NGC-7769 and 7771 in Pegasus. Finally I stopped to explore all three main sections of the Veil Nebula, which looked like a bridal veil through the 24mm Explore Scientific 82 degree eyepiece and an O-III filter. The North American nebula showed streaks and patches of dark and bright nebulosity, and I traced the full outline of NGC-6888, the Crescent Nebula and NGC-281, the Pac Man nebula. I also gazed upon the Lagoon, Triffid, Eagle and Omega nebulae. I also observed scores of planetary nebulae, including NGC-6905, 6826, NGC-40, and M-57 and M-27. I was happy to be able to observe from a spot darker than my driveway, and to see objects that are impossible to see at home, even with a 15-inch.

 
 
 
 
 


Thursday, August 15, 2013

Bright Nova in Delphinus

Some 36 hours ago, a nova appeared in Delphinus, which has rapidly brightened to fifth magnitude. It is near the planetary nebula NGC-6905, which is easy for a 6-inch from a good site. This is apparently a fast nova, one which brightens very rapidly and fades almost as quickly, and there has been no known previous outbursts. That makes it a classical nova. I do not know the distance to the system, which will reveal the luminosity of both the nova and the two stars that gave rise to it. However, the star system was at 17th magnitude before the explosion, and it is very far away from Earth, at least 12,000 light years and possibly nearly twice that. Below is a drawing I made last night through a hole in the clouds. The nova is very conspicuous because no fifth magnitude star exists at its position, and it shines with a yellowish white color. As it fades, it will likely gradually yellow then redden before fading to normal, where it will be a very faint, hot blue or white star. To make this drawing I used my 10-inch F/4.5 Dob with a 24mm Explore Scientific 82 degree eyepiece. The pair yield a magnification of 55X with a Televue coma corrector in place and a true field of view about 1.5 degree across. The planetary nebula is also quite conspicuous, with about 45 arc-minutes separating nova from the planetary nebula. This nova is going to start fading very soon, if you wish to see it, don't delay. Below is a link to an article that will show you where to look for Nova Delphini 2013.

http://www.skyandtelescope.com/observing/home/Bright-Nova-in-Delphinus-219631281.html

Wednesday, June 26, 2013

Spring NGC galaxies

Amazingly, a clear and cool night came that offered good skies and moderate for my area, dewing. I loaded the 15-inch into the car and headed out to a darker site than the driveway in search of galaxies not observable from home. I quickly found the sky conditions made the hour long trip worth while. The mosquitoes were out in force, fortunately I remembered to bring the bug repellent. First on the list was the Whirlpool Galaxy, also known as M-51. The spiral arms were clearly apparent, and so was the structure of the companion, NGC-5195. Not only was a brighter core evident, so was the "bridge" that appears to link it to M-51 as well as the comma like shape. Both were an impressive sight at 227X, and the distortion of the larger galaxy by it's interaction with NGC-5195 was also evident. M-51 is one of my most favorite galaxies, and one of the most impressive in the northern skies.
Two objects of interest I had wanted to look over in Hydra were the elliptical galaxies NGC-3904 and NGC-3923. NGC-3904 was fairly bright with an obvious central core, and like most elliptical galaxies it has an oval shape. From a good site it's fairly easy to see, it definitely does not require a 15-inch to bring it into view. Aside from the brightening towards the center little if any structure was apparent at 227X. Shining at 11th magnitude, NGC-3904 has a small apparent size of 1.9 X 2.7 arc-minutes.
Nearby also lies another elliptical galaxy in Hydra, NGC-3923. This galaxy is larger in apparent size and brighter at an apparent magnitude of 10.1. I've managed to spot it from my driveway with the 15-inch when sky conditions were very favorable. Like NGC-3904, this galaxy has an oval shape but a weaker brightening towards the center. A quite easy object from a good site, it definitely is a galaxy small telescopes can reveal to backyard astronomers.
One class of objects that always intrigued me are trios, quartets and even larger assemblages of galaxies visible in one view through a telescope. Hickson 61 is one such object I have observed before with my 10-inch, but I was then only able to see the bright elliptical and lenticular galaxies. This time the fourth galaxy appeared when I brought the 15-inch to bear on it and ran the magnification up to 300X. It was very faint and was only seen with averted vision. Interestingly, it is not associated with the other three, it is in fact a foreground system far closer to us. The galaxies of Hickson 61 are NGC-4169, NGC-4173, NGC-4174 and NGC-4175, with NGC-4173 being the faintest. NGC-4173 is a flat Scd galaxy with a magnitude of 12.7 and an apparent size of .7 X  5 arc-minutes. It appears as a ghostly streak pointed in the same direction as one of it's brighter neighbors. NGC-4169 is a magnitude 12.3,  SO lenticular galaxy with an apparent size of 1.8 X .9 arc-minutes but it looks smaller than that through the eyepiece. It has a very bright inner core. NGC-4174 and NGC-4175 shine at magnitude 13.5 and 13.4. Their small apparent sizes give them fairly high surface brightnesses, enough to make spotting them through modest telescopes not too difficult even from less than very dark skies. With the exception of NGC-4173, the other three galaxies are members of a galaxy group whose brightest member is NGC-4169. This quartet is a captivating find for those who enjoy observing galaxies and galaxy groups.
Virgo holds many fine galaxies for amateur telescopes, so many in fact it's difficult to give all of them the observation they deserve. Two such galaxies are the elliptical system NGC-4261 and the barred spiral or possibly lenticular system NGC-4264. NGC-4261 is very bright, so bright I was able to see it with ease through the 15-inch at home. NGC-4264 required a drive outside of Mobile to be seen with the same telescope. Both made a fine pair from a reasonably dark site, and they certainly would be accessible to a 6 or 8-inch telescope.
NGC-4570 is a flattened, nearly edge-on lenticular system also in Virgo that is overshadowed by the Messier and better known NGC galaxies there. It is however a quite interesting galaxy in its own right, with a long spindle like outline and an elongated bright inner core. Quite small, it withstands high magnifications through larger telescopes. NGC-4570 has a magnitude of 10.9 and a high surface brightness of 12.4 due to it's small apparent size of 1.1 by 3.8 arc-minutes.
NGC-4596 is another lenticular or a transitional lenticular-barred spiral galaxy in Virgo. Very bright at magnitude 10.5, I noticed the inner region was elongate but did not see the bar that is apparent in photos. Surrounding the inner core was a faint, oval hazy halo. Although it's brighter than NGC-4570, it appears dimmer through the eyepiece due to it's considerably lower surface brightness of 13.3 and larger apparent size of 3 by 4 arc-minutes. This galaxy probably would reward users of large telescopes from dark skies seeking to see evidence of it's barred spiral structure, but my observing site is not quite dark enough for that.
Yet another bright elliptical galaxy in Virgo is NGC-4636. Shining at magnitude 9.7, this galaxy shows a very rapid brightening towards the center and an egg shaped outline. Otherwise in appearance NGC-4636 resembles an unresolved globular cluster. Much larger than the previous Virgo galaxies in apparent size, NGC-4636 has a surface brightness of 13.3 and an apparent size of 6 X 4.7 arc-minutes. This is an easy object for a modest telescope from a good site.
Bootes does not have the rich assortment of galaxies within reach of amateur telescopes that Virgo does, but it does have some galactic treasures of its own. One such treasure is the galaxy trio NGC-5529, PGC 50952 and PGC 50925. The NGC galaxy is an flat Sc spiral galaxy nearly edge on with a magnitude of 12.2. It is quite faint and difficult for smaller telescopes unless the skies are very dark. From the light polluted site I found it from, it was a very dim slash with a elongated, weak central brightening. The two PGC galaxies, both of which are nearly 15th magnitude objects were only visible through averted vision as very faint, featureless oval blobs, with a slight if any central brightening. I had to jiggle the telescope to be sure I was actually seeing them and not random noise in my vision. NGC-5529 has a surface brightness of 13.8 and an apparent size of 6.2 X .8 arc-minutes. Despite its listed apparent magnitude, under the conditions I was observing this trio NGC-5529 appeared to have a magnitude closer to 13 to me. No sign of the dust lane appeared, nor did I see the warping in the disk. Both probably would appear from a darker site in a future trip to a star party.
Much brighter in appearance is the Bootes galaxy NGC-5689, a SB-0 barred spiral galaxy nearly edge on. Shining at magnitude 11.9, it has a fairly high surface brightness due to it's apparent size of 1 X 3.5 arc minutes. It sharply brightens towards the center, and is the brightest member of a small group of galaxies. The core appears elongated or seems to have wings, where the central bar is located.
The final galaxy I drew was diminutive NGC-5820 in Bootes. Very small it required 298X for the best view, which fortunately the seeing allowed that night. This lenticular galaxy has a magnitude of 11.7 and a high surface brightness of 12.2 due to it very small apparent size of 1.7 X 1.1 arc-minutes. Unlike many galaxies, NGC-5820 responds very well to high magnification. Nearby is another much dimmer galaxy, NGC-5821 which I did not notice that night. Very faint and small, it's apparent magnitude of 13.8 and being directly behind a foreground star in the Milky Way makes it a tough proposition from the usual skies I observe from. I plan to return to this pair at a very dark site to sketch the field again. NGC-5821 itself is a spiral galaxy that is difficult even in large telescopes, unlike it's far brighter neighbor.
 
This night was a most rewarding foray deep into the wider Universe. While observing and sketching these objects, I stopped by some other galaxies and star clusters too. NGC-5248, the brightest galaxy in Bootes showed signs of it's spiral structure, and the globular cluster NGC-5466 also in Bootes resembles a swarm of fire flies in the darkness at 227X. I also looked at the Lagoon, Trifid and Swan nebulae in Sagittarius, all of which showed magnificent views of their structure. M-4 displayed it's central bar even at low power, with stars showing hints of their actual colors at 227X. Nearby M-80 showed itself as a tiny pinch of sand, and the dim little globular cluster NGC-6144 near Antares also partially resolved into very faint stars. In smaller telescopes from my area, it appears merely as a faint blur. The Scorpius globular M-62 showed it's lopsided nature and nearby NGC-6441 also resolved into stars around the outer edges at 298X. In Sagittarius, the open cluster NGC-6520 and it's associated dark nebula B-86 looked as though someone cut out a piece of the sky and dropped it. B-86 looked like the dark cloud of gas and dust it is, it's very apparent at 227X. M-22 also showed thousands of star, some of which glowed with a reddish orange color. It was a memorable night under the stars, one an amateur astronomer can never see too many of.

Thursday, May 30, 2013

Planetary trio in the western sky


For the past several days, the planets Mercury, Venus and Jupiter have gathered together into a small region of sky. Through my 6-inch F/8 Dobsonian telescope, Mercury looked like a tiny, featureless gibbous moon with an orange tint. Venus was a tiny round, yellow-white disk. Jupiter showed it's oval shape, equatorial belts and Galilean moons. At 109X the poor seeing was evident, as was a prismatic color effect caused by refraction from their light passing through our atmosphere. It was beautiful and at the same time a good demonstration of why billions have been spent building space telescopes.

The next night I opted to photograph this conjunction which widened dramatically over 24 hours. I used my old Nikon F-3HP, a Leitz Tiltall tripod and 55, 85, 135 and 180mm lenses to take the pictures you see here. I used 200 speed Fujicolor film for color prints, exposing it for up to eight full seconds in the deepening twilight with the lens stopped down at first. A cable release was used to avoid jiggling the camera and blurring the images. Even though the camera's internal light meter was able to read the dimming scene, I bracketed my exposures to be assured at least a few will be correctly exposed. When it was nearly fully dark, I used f/stops ranging from wide open at F/2.8 to F/5.6. I used long exposure times because I wanted to record passing vehicles on the I-10 Bayway as white and red streaks. The location I used to photograph this event was a parking lot overlooking Mobile Bay, and the I-10 Bayway with the city of Mobile Alabama in the distance.

Once I had exposed film in hand, I took it to a local photography supply center for processing. I then scanned the negatives with a Canon Canoscan LIDE700F flatbed scanner that can also scan unmounted film at very high resolution. It is not ideal for those who must scan large numbers of 35mm negatives and transparencies on a daily basis, but it is well suited for those who mainly need to scan documents, photos and the occasional negative. It is a USB scanner that can also be used to copy and print documents if a printer is also connected to the computer. Conjunctions like this one are always nice to watch, they offer the chance to see two, three or even more planets in one session.

Tuesday, May 21, 2013

Galaxies galore and a departing comet

Finally after a long period where either the weather was bad or I was able to observe only at home, an opportunity came to observe my favorite kind of object from darker skies than I see at home, galaxies. While there I also took a look at the now departing comet 2011L4PANSTARRS and a elusive globular cluster. My original plans were to observe from a nearby state park, but when I arrived there it was clear that was not possible so I went to another site accessible to me. I took the 15-inch there along with my full array of eyepieces and filters. Upon arrival during the deepening twilight, I quickly set up the telescope and got down to the business at hand, observing and sketching deep sky objects. I also made use of the Sky Commanders, whose accuracy allows me to spend more time observing than searching for objects.
 
After a having a look at the crescent moon and Jupiter low in the western sky, comet PANSTARRS was the first object I looked at and sketched that night. Venus was also visible, but since it just emerged from superior conjunction and was very low in the sky I did not look at it that night. Now deep in the northern sky in Cepheus, PANSTARRS is a pale shadow of what it was when it came into view last March. Shining at eighth magnitude, it was still a nice object for a telescope, resembling a lopsided or interacting spiral galaxy with an off-center nuclear region. Closer inspection showed the coma was fan shaped, and there was no sign of a tail evident. The comet was low in the sky and the observing site was far from being what would be called very dark. I'll follow it as long as I can since it will remain near Polaris for the next six weeks or so before it heads south again and fades out of sight.
M-65 is a Sb-type spiral galaxy in Leo that is currently undergoing a supernova called SN2013am, but my hopes of seeing it faded when it became clear it was heavily obscured by dust clouds in the galaxy. The galaxy itself shines at magnitude 9.3 and has a length of 10 arc-minutes, large for a galaxy. As a consequence, it was not evident when I looked at it, but the bright nucleus and subtle hints of spiral structure were visible. It was impressively large in the field of view at 227X. This is definitely one of the finest galaxies visible in the spring sky from the northern hemisphere for almost
 any telescope from a good site.
Only some 38 arc-minutes away from M-65 is M-66, another spiral galaxy in orbit around M-65. This disturbed Sb spiral shines at 9th magnitude but is slightly smaller at 8.7 arc-minutes long. Both are visible together at lower power through the 15-inch, and in smaller telescopes the larger but fainter edge-on spiral galaxy NGC-3628 can be seen with M-65 and M-66. Unlike the nicely symmetrical M-65, M-66 shows irregularities in it's disk. I can see hints of a "crab claw" like spiral arm on one side and a smaller spiral arm on the other side of the bright nuclear bulge. While I did not sketch it, I did take a look at NGC-3628, whose dust lane was very apparent, and so was it's distorted, long, box like shape. It was brighter than I had ever seen it through a smaller telescope. I plan to sketch this one before it gets too near the Sun to see. Together with M-65 and NGC-3628, these galaxies form the Leo Triplet, one of the best examples of a galaxy trio for small telescopes.
Ursa Major like Virgo is a galaxy hunter's playground, with hundreds of NGC and IC galaxies that can be seen with amateur telescopes from dark sites. I started with the oval elliptical NGC-2639, which showed nothing else other than a steady brightening towards the center. It was bright and small, which made it easy to find even though it shines at magnitude 11.8. The small apparent size of two arc-minutes enables it to punch through sky glow and haze easily.
Longer but narrower than NGC-2639, NGC-2654 is a bright edge on lenticular or spiral galaxy with an apparent size of 4.3 arc-minutes and a magnitude of 11.8. It's precisely edge-on and shows a bright core. This galaxy unlike many edge-on systems has a high surface brightness and is therefore not a difficult object from less than truly dark sites. Like NGC-2639, this galaxy is also circumpolar from most of the northern hemisphere, and therefore can be seen just about any time of year.

NGC-2793 is another small but fairly bright elliptical galaxy in Ursa Major. Shining at magnitude 11.7, this somewhat oval shaped system has a small but bright inner core, no doubt swarming with billions of older yellow and red stars with a super massive black hole lurking at the center. This galaxy is not however circumpolar. A quite easy object for the 15-inch and no doubt someone from a moderately dark site will find it with an 6 or 8-inch telescope due to the fairly high surface brightness that stems from both it's small apparent size of 2.2 arc-minutes and the stars being densely packed like a giant globular cluster. Indeed, it resembles an unresolved globular cluster through the telescope. Like most ellipticals, this galaxy is otherwise featureless other than the bright inner core.
After moving on from the abundant galaxies near Ursa Major's nose, I turned my attention to Hydra the water snake and her rich array of galaxies. Hydra like Ursa Major is a great constellation to find all kinds of galaxies, from dwarf systems just beyond our local group to massive and very remote galaxies that will test the largest of amateur telescopes to their limit. NGC-3091 is the largest and brightest member of a small group of galaxies. Another much smaller and fainter member was visible, NGC-3096. NGC-3091 itself is an elliptical galaxy which is about 2.2 arc-minutes across and shines at 11th magnitude. NGC-3096 is much fainter at about 13th magnitude and appears as a minuscule oval glow. The three other PGC galaxies that also are in the same vicinity I did not see, probably because the skies were not dark and clear enough, but they can be seen with a 10-inch or even smaller telescopes from a dark site.
The interacting pair of galaxies in neighboring Sextans the Sextant has a distant companion I was unaware of until this spring, so I took the opportunity to see if it would be observable. Sure enough just to the west of the tenth magnitude galaxies NGC-3166 and NGC-3169, NGC-3156 appeared as an small oval shaped object with a brighter center. It was surprisingly visible despite the sky glow it had to compete with. It's about 12th magnitude and has an apparent magnitude of about two arc-minutes.
Leo has an embarrassment of riches when it comes to galaxies, so many bright ones are found there that there are others that are passed over such as NGC-3162 in Leo's neck. Not a match for M-65, M-66 or any of the other three Messier galaxies, this oval galaxy is not terribly hard for an 8 or 10-inch under less than perfect skies. This spiral galaxy is about three arc-minutes across and shines at magnitude 11.6. The nuclear region was bright and slight mottling seemed to be in the disk, but I wasn't sure what I saw until I looked at a photo of the galaxy after returning home for the night.
This bright elliptical galaxy NGC-3585 adorns southern Hydra, which seems to have an abundance of elliptical systems in her borders. Very bright with a bright core, this galaxy is visible in small telescopes as an oval shaped 10th magnitude object. The apparent size is three arc-minutes, and other than the brightening towards the very center, this galaxy is otherwise quite featureless.
Unlike all the other NGC galaxies observed that night, NGC-3621 is larger and or brighter than all of the NGC galaxies previously described. Shining at 10th magnitude with a length of 10 arc-minutes, this galaxy looks both larger and fainter than NGC-3585 even though both have the same overall magnitude. This Sc class spiral displays a brighter nuclear region and a very large glowing disk around it. It resembles M-33 tilted closer to edge-on than face on as that galaxy appears to us. The disk was quite faint and seems patchy, and in photos there are numerous star formation regions present. It's also nicely set in a kite shaped asterism of foreground stars which belong to the Milky Way. Although it was hindered by the sky glow, this would be a magnificent spiral galaxy that is equal to many Messier and indeed superior to some in size, brightness and visible structure from a dark site. NGC-3621 was a nice find given most galaxies in Hydra are much fainter and smaller.
At last midnight came and went, and I was beginning to grow tired as dew began to drench everything including the telescope. So I decided to chase one last object before packing up and going home. The globular cluster NGC-5053 frustrated me even though the nearby and much brighter M-53 is easy to see even from home. I finally succeeded in finding it from the airstrip once before with the 15-inch, and from a roadside field I succeeded again.  Both M-53 and NGC-5053 are within 2,000 light years of each other, but they are in independent orbits around the center of the Milky Way. While M-53 is small, rich in stars and quite bright, NGC-5053 is the opposite. It has five times fewer stars than M-53, and it's stars are spread out across 10.5 arc-minutes and the whole cluster shines at magnitude 10. These factors dilute the cluster's light so much it appears as a round, dim, hazy glow peppered with faint glimmers of it's very brightest stars. It was almost like a miniature version of Bernice's Hair, which refers to a famous queen who lived in the early third century A.D. in what is today Benghazi Libya. Famed for her beauty and long blond hair, she sacrificed it as an offering to the Gods to ensure her husband's safe return from a war. NGC-5053 and M-53 are a great opportunity to demonstrate that globular clusters are not alike.

Monday, April 15, 2013

PANSTARRS

As expected, the PANSTARRS comet finally came into view from the northern hemisphere in the middle of March. It turned out to be a lot more difficult to see, it was so low in the western sky I was only able to see it twice before it begun to fade. Then the weather and a change in my work schedule ensured I was not able to see the comet for the past three weeks. It is now heading towards Polaris and will get higher in the sky even though it is also fading. I am not overly discouraged, it was the closet comet yet to the Sun I was able to observe, and it looked a lot like a rocket seen from a great distance through a camera attached to a tracking telescope.  I am just hoping the ISON comet will at least be moderately bright in the predawn skies this winter.
When this sketch was made, I was looking at PANSTARRS from a spot that overlooks Mobile Bay, which gave me about 45 minutes to watch the comet before it dove below the western horizon. I opted to take along my trusty 6-inch F/8 Dobsonian instead of the usual massive 15-inch due to the location and the fact time was of the essence. Sweeping side to side with the 24mm Explore Scientific 82 degree eyepiece, it wasn't long before I located it. It was much smaller than I expected and I was looking through  both thin clouds and a lot of skyglow from the fading twilight. The comet was very bright despite being near the horizon, with a strong yellow cast and a concentrated inner core. The beginnings of a tail projected away from the nuclear region much like the exhaust plume from a rocket at high altitude. I will sketch the comet again when I can bring my larger telescopes to bear upon it. To get a better view requires looking for it from a darker site than the parking lot behind a convenience store and a restaurant.

Friday, March 15, 2013

Winter open clusters

The weather of the past few months has been unusually cloudy and rainy, with tornadoes hitting my city twice in one week during the Christmas holidays. But a few clear nights came along between the frequent storms of this winter, and naturally I made use of them. As of late I was concentrating on the open clusters of the constellations Canis Major and Puppis, two winter constellations that lie along the winter Milky Way. Here an amateur astronomer can find any kind of deep sky objects from galaxies to unusual stars.  Since I was observing from home, I concentrated mainly on open clusters. In Canis Major and Puppis you can find open clusters that range from those which are visible to the unaided eye to others which are faint blurs visible only in large telescopes.
 
 
NGC-2345 is a large scattered open cluster in Canis Major. Shining at a magnitude of 7.7 and with an apparent size of 12 arc minutes, NGC-2345 was easy to pick out from the background star fields. It's stars were rather faint, this spray of stars is an easy find in medium sized telescopes.

 
Larger and brighter NGC-2354 is less obvious amid the star clouds of Canis Major, even though it shines at magnitude 6.5 and has an apparent size of 20 arc-minutes. This star cluster lies in between Delta Canis Majoris and the bright open cluster NGC-2362. It's stars are more scattered, numerous and  fainter than the members of NGC-2345. They are arranged in chains that seem to enclose dark voids within the star cluster's apparent boundaries.
 
 
NGC-2374 is another Canis Major open cluster I had wanted to take a close look at, but it's apparent size of 19 arc-minutes and magnitude of 8 makes it appear quite faint through the telescope. There seems to be a five pointed star like concentration of stars in this object, which amid the countless background stars in the winter Milky Way made NGC-2374 an interesting sight. Since this object is two thirds the apparent size of the full moon, the star cluster occupies most of the field of view at 181X
 

NGC-2383 is just as bright as NGC-2354, but much more concentrated and rich with brighter individual stars. It stands up well to quite high magnifications and stands out well against the background star fields even when there's substantial light pollution.  Shining at an apparent magnitude of 6, NGC-2383 has an apparent size of 8 arc minutes, or a quarter of the width of the full moon.

 
NGC-2414 in Puppis is a small and rich open cluster with a prominent bright star in the center. Through my 10-inch it was easy to make out from my light polluted driveway at 149X. This star cluster is only 4 arc-minutes across and shines at magnitude 7.9, making it able to penetrate urban light pollution and stand out well against the background star clouds.

 
NGC-2423 lies just to the north of the bright open cluster M-47, and therefore is often overshadowed by it's brighter and larger neighbor. Shining at magnitude 6.7 with an apparent size of 19 arc-minutes, NGC-2423 boasts a large population of moderately bright and fainter stars.

 
NGC-2440 is a bright planetary nebula with a bi-polar inner region surrounded by an oval outer shell. It responds well to an O-III filter and the inner peanut shaped region is very evident. I was not able to see the central star due to the poor seeing. Around the bi-polar inner region there is a fainter outer shell that is faintly visible, with the whole nebula shining at a magnitude of 11. It's apparent size of 30 arc-seconds results in a high surface brightness, making this nebula visible to suburban stargazers.

 
NGC-2451 is a very bright open cluster easily through binoculars or a small telescope. In the center is a bright yellow-orange star surrounded by fainter blue-white and white stars. This star cluster is at least half again as big in apparent size as the full moon, with a total magnitude of 2.8. My 24mm Explore Scientific 82 degree eyepiece comfortably took in the entire star cluster through the 15-inch, which was set against a rich starry background. This object is one of the jewels of the southern skies that is nicely visible from the southern United States.


NGC-2489 resides in the northern reaches of Puppis about 8 degrees due east of the bright star Adhara, or Eta Canis Majoris. Shining with an apparent magnitude of 7.9 and an apparent size of 8 arc-minutes, this star cluster is a good object for a small telescope under favorable conditions. It seems to display a dark central void through the 15-inch from the driveway, even though long exposure photos show the area filled with stars too faint to see from there, even with a 15-inch. As open clusters go, it's fairly concentrated and rich with at least two dozen members.


NGC-2527 is a very large but rich open cluster that spans 22 arc-minutes of sky. It's overall magnitude of 6.5 is misleading because the star cluster is composed of a large number of 10th magnitude and fainter stars, making it somewhat of a ghost object hiding in plain sight. From my house it eluded detection through my smaller telescopes, but it showed up plainly through the 15-inch. From a dark area it would be a good object for a modest telescope.

 
Like it's nearby neighbor NGC-2451, the open cluster NGC-2546 is a very large object that takes up much of the field of view at low power through the 15-inch. Unlike that star cluster, NGC-2546 is made up of much fainter 9th to 12th magnitude stars that are arranged on several groups, nor is there a single bright star or lucida in the center. The whole cluster is some 41 arc-minutes across, bigger than the full moon. Shining at magnitude 6.5, it is visible to small telescopes and binoculars from darker locations, especially from the southern hemisphere.

 
NGC-2567 is another Puppis open cluster I paid a visit to. This object has a formation of stars that runs through the center as a wavy line. With an overall magnitude of 7.4 and an apparent size of 10 arc-minutes, NGC-2567 needed medium magnifications to reliably pick out from the background star clouds and Mobile's light pollution. Fairly rich with 11th magnitude and fainter stars, I located it with smaller telescopes from home with little difficulty.
 

Less than two degrees to the north lies NGC-2571, another open cluster that has a similar appearance at the same magnification. It's slightly brighter at 7th magnitude but the larger apparent size of 13 arc-minutes gives it a similar appearance to NGC-2567.

Normally I prefer to observe galaxies and nebulae, but inclement weather and other considerations ensured I was observing at home for most of the winter. I always wanted to get a closer look at these open clusters while they were still in a good position to observe. There's still a number of galaxies and nebulae in this area I would like to observe, but soon Puppis and Canis Major will be lost in the glare of the Sun, and numerous galaxies await my attention, as well as the now visible PANSTARRS comet. Soon I will be posting drawings of this icy visitor from deep space.