Namibia 20/26 April 2009 Part Four
( Episode 1: general description )
( Episode 2: star clusters )
( Episode 3: nebulae )
finally conclude the report of the observations of the southern sky . In this latest installment we talk about galaxies, including of course the legendary Magellanic Clouds.
Obviously not list one by one all the individual galaxies, because they are really a lot, but describe the most important and major groupings or clusters.
Start with the part of the sky to the north of the Milky Way, where lies the constellation Hydra. Finally I was able to see NGC 3109, which I had missed previously because Casera Razzo always fell behind the mountain five minutes before I tried to point it! This is a large elongated irregular galaxy about 17 ', and is the device of our local group. Heading east is the beautiful spiral NGC 3621, consisting of a large nucleus and bright as M81 but more irregular arms and outer glow very weak.
Then there are two beautiful cutting galaxies, NGC 3717 and 3936, the elliptical NGC 3885, 3923, 3904, and finally the queen of this constellation: the Southern Pinwheel, aka M83. It 's very difficult to describe what you see if it is high in the sky, we have admired for good by comparison with both Dobson. As early as 25 cm were very easy and the spirals showing various details, then in 50 ... Always
hydro, there is also a good group led by NGC 5078 but I have not looked on this occasion. Instead I moved briefly to the north to see my best Sombrero (M104) of all time and also the famous Antennae in Corvus (NGC 4038/4039). Of the latter had not seen the very small arms but the nuclei had few details.
brings us to the Antlia, constellation anonymous and difficult to detect, but inside it contains a myriad of untold galaxies! The largest is NGC 2997, a magnificent spiral seen almost face-with arms very bright and has little to envy to the most famous turning of the first. The declination is more or less the same as that for M83, with a little 'hard work, can also be seen from Italy. Then there is a spectacular
storage, slightly lower (-35 °) but still affordable by our south. If I'm not mistaken is the third largest in the sky after Virgo and Fornax, and its main components are NGC 3258/3268/3271/3281 etc.. It is to literally get lost in and I with two feet and a field of 50 'I saw a dozen galaxies at a time, an unforgettable scene!
Then there are other nice little groups like NGC 3095/3100/3108, NGC 3113/3137/3175, NGC 3223/3224, NGC 3347/3354/3358. In all in this constellation I scored as many as 36 galaxies!
And then comes the Centaur. Needless to say, NGC 5128, also known as Centaurus A, was one of the main target of this expedition, as a galaxy is unique and there is not any that even remotely resembles. In other words, completely revolutionizes the concept of "black band"! This feature that bisects the ball of light is already clearly visible at low magnification in 80 mm, and then in the large openings are completely detached from the background and a slight fork in 'Y', with a star just above the point of separation ! It turned out instead
a bit 'disappointing NGC 4945, because despite being a giant slug of 18', is very weak and virtually no details. I expected a great copy of M98, with lots of light and shade, and yet it is little more than a diaphanous spot. You can not say it's ugly, but given the photographs and the excellent observing conditions in which I would find myself, I expected more. Nearby there are also elliptical NGC 4945A and NGC 4976. Stumble
NGC 5102, we might call the "Phantom of centaurs iota" of the proximity to the star in question, making it similar to NGC 404 in Andromeda (and is also the case for elliptical!).
Then I looked some more and in galassietta Cen A and omega center, while I have not had time to look at other in the north-west to the border with the Hydra.
conclude this first part with three spiral galaxies in the Wolf: NGC 5530, IC 5643 and 4402, respectively 3 / 4, to face and cutting.
Now climb over the galactic plane and we move in the constellation Fornax, the fate similar to that of Antlia: asterism as insignificant, but phenomenal in terms of the objects within it. Although in April it saw very low in the early evening, I was able also to give you some quick look before it went down. The ammmasso is located on the border with dell'Eridano mouth, and galaxies are more elliptical NGC 1316 (Fornax A), NGC 1374/1380/1387/1399/1404 and barred spiral NGC 1365.
All I have seen 19, but there are many more because I skipped all those in the northern constellation (from 1097 up to speak) because at that time were not much higher as seen by us, and then try with more time to observe Italy soon. Even in the southern part
dell'Eridano there is something cute, like NGC 1532, but a sort of sombrero with an arm that extends to the outside and the small companion NGC 1531 perpendicular to its core. Perhaps this couple is similar to M51 except that it is seen almost instead of cutting his face. Then there is NGC 1269, a disc galaxy similar to M94, with bright nucleus and then the outer glow is difficult to see due to glare.
go to clock, we find the deformed galaxy NGC 1249, the barred spiral 1433, then 1448 to cut the face of 1493, and the pair 1510/1512. In short there is something for everyone!
in Colombia, not far from the globular cluster NGC 1851, there's quite a trio of galaxies aligned within a degree and a half: NGC 1792/1808/1827.
Then there is the golden fish that, as if not more, than the cloud also contains many fine galaxies more "normal". Moving from north to south are: NGC 1515 with the cutting side of the sixteenth 1515A, NGC 1566, spiral semibarrata, a group of elliptical in its surroundings (NGC 1549/1553/1617), and the two spirals of NGC 1672 and 1703 face. In
Lattice stands the beautiful irregular galaxy NGC 1313, 8 'in size. It 's very bright and full of detail, with well-perceived HII regions. Can be defined as a cloud of Magellan in miniature, and coincidentally is also about half way between them!
from another galaxy NGC 2442 is in spectacular shape voltante Fish. No need to say why, just look at the photos.
For those who still want to try their hand stuck to bright stars in galaxies, in Hull is the Phantom of Miaplacidus, NGC 1822. And, even if on purpose, this is elliptical!
On the main there are three major discrete spirals, NGC 6215/6221/6300, while the nearby Peacock we find one of the largest (20 ') in the southern hemisphere, namely NGC 6744. But the second half proved to be disappointing after the cutoff of the Centaur, because I would have expected a beast as M81 or M101, whereas its spirals are much more fleeting and difficult to discern, even with half a meter. So I found it more like a cross between NGC 6946 and IC342, although the nucleus brighter than these two. Is also an object to look absolutely if you make a shipment over the equator, because there is the interesting detail of the outer arm to the north which crosses the galaxy NGC 6744A with the perspective of magnitude 15, a real challenge!
The Indian medium and small swarms of galaxies, it is pointless to list them all but I must mention the beautiful cut of NGC 7090 long 7 '.
Even in the beautiful constellation of the Crane is to be lost, but given the unfavorable season for your comments, I just look at the most important group, which consists of NGC 7496/7552/7582/7590/7599/7632 In addition to planetary nebula described in the previous episode.
Same goes for the sculptor, that could be seen down just before dawn. The main galaxy (NGC 253) was virtually cut off and I would not view some of the best from Italy, so I focused on other major companion galaxies in its group, located in southern declinations, and then, for Fortunately, more visible in that circumstance.
Large spirals NGC 300 and 7793 are obviously very good but the meanness did not do them full justice, while the 55 was a scream! It 's a huge sigarone 125X half a degree that filled the whole field, with swelling evident irregular on the west, while the two extremities faded and seemed to never end! E ' was undoubtedly the most beautiful of the novel set in Centaurus A. In Phoenix
instead there is virtually nothing, apart from little things reserved for fans of the various small groups as Stephan, Copeland, et cetera. For here we find the quartet of Robert, whose components are of magnitudes from 13.8 to 15.0, and catalog numbers are NGC 87/88/89/92. Even the nearby PGC 1452 is easier than 3 out of 4 members of the group! (But then why was not included in a catalog more "noble" as NGC or IC?).
Tour is almost finished, now come the main dishes ...
Magellanic Clouds
Before the trip I had poked around in a forum di astrofili australiani per leggere i loro commenti sulle due principali galassie satellite della via Lattea, e sono unanimi nel considerarle gli oggetti più spettacolari e ricchi di tutto il cielo, aggiungendo che noi poveracci dell’emisfero nord non abbiamo la minima idea di cosa siano finché non le vediamo! E infatti ho potuto verificare che hanno pienamente ragione. Mi è venuto il dubbio che la mia impressione tendesse a sopravvalutarle un po’ per via dell’ovvio effetto novità, ma sembra che gli australiani non si stanchino mai di vederle sempre, e addirittura c’è chi ha rinunciato alla possibilità di andare a vivere negli USA proprio perché non voleva perdere le sue amichette!
E anche io ormai consider incomplete sky with a low shot galactic core and without the Magellanic Clouds, and I can not think back to all those daily hours spent in perdermici.
Another consideration is that they are good for any aperture and any enlargement, because every circumstance highlights a number of details:-
to the naked eye are perceived main forms: the small is shaped like a pear, with the most "chubby "SW, while the largest is almost round, with the center the great light bar elongated in the direction EW (a bit 'like the capital Greek letter Theta). The Tarantula Nebula (NGC 2070), to the east is visible in averted.
Just to give you an idea of dimensioni, per coprire interamente la Grande Nube ci vuole (a braccio teso) un pugno chiuso!
-col binocolo o con un telescopio a bassi ingrandimenti si intuiscono le strutture principali quali i pseudo-bracci, gli oggetti più grandi, le diverse densità stellari, e tutto l’aspetto è brizzolato, cioè si capisce che è un grande insieme di stelle anche se non si risolvono nitidamente.
-coi Dobson si possono approfondire singolarmente tutte le decine di oggetti contenuti, tra nebulose, ammassi aperti e globulari. Essendo galassie giovani e irregolari, sono estremamente ricche di regioni HII, e trovandosi in posizione di faccia (in particolare la grande) non ne è pregiudicata la visione, a differenza della Via Lattea that prevents us from seeing the objects in more than half of its volume because it is cutting.
In these clouds is sufficient to move the event far and wide to see in each field at least one or more objects, and with a decidedly Dobson is an easy and fun. If you want to identify clearly what you see, then you need to get steady work with a map and a detailed object-hopping!
think that in two nights I've been watching the cloud for more than three consecutive hours, I was totally caught as a drug! After a while, 'I began to say: "enough is enough, I have to watch something else," but then continue to go over that immense maze back and forth, and eventually I stopped only when it became too low horizon. Fortunately that should not go in the southern hemisphere in the summer once or else you would risk going there in December to observe only there for a whole night!
The cloud was rising rather less at night, and being smaller is not this speech, and then there's the globular to attract attention!
To understand that I am not exaggerating at all enough to see a detailed map as Google Sky or this beautiful mosaic labels.
And thanks to these pictures do not need to list all individual items, but I just describe the main ones. Most
parte sono catalogati come NGC e IC, anche se ce ne sono alcuni di rilevanti che però sono inseriti solo nei cataloghi specifici per le nubi, come ad esempio il globulare Kron 3, situato prospetticamente vicino a 47 tucanae.
Si nota subito che la Piccola Nube, in proporzione, è più fornita di ammassi globulari, e in assoluto devono essere anche molto grandi vista la distanza. I più grossi sono NGC 330/339/361/416/419. Non illudetevi di risolverli facilmente, sono una sfida ardua esattamente come i globulari del Delfino e della Lince...
Le nebulose maggiori sono NGC 346/371/395, situate nella zona NE. Facili, luminose, contrastate e dettagliate. I filtri UHC od OIII comunque sono sempre utili. A SW invece troviamo NGC 261 e 267, and finally in the SW suburbs, leaving the dense part of the cloud, NGC 456 and stand 602.
Turning to the older sister, the eye automatically falls first on the Tarantula, in one of the most haunting of all the heavens, if not the best. Here, as the Centaur and the hull, we pulled the screaming at first glance be censorship.
We're talking about a cloud of 20-30 'with a surface brightness comparable to that of M42 and a lot of details and dizzying contrasts, and to make matters worse is surrounded by equal volume of various objects, and so if we consider the whole complex to NGC 2084, obtained a field of about 1 ° which is a total uproar! The nebulae that surround the main are NGC 2048/2060/2069/2074/2077/2084, 163/164 Henize, then we have the globular clusters NGC 2100/2108 and NGC 20372042/2044/2050/2055/2081/2093 open. To get an idea of \u200b\u200bwhat you see us just take a picture as the one linked before and put it in black and white! And those clusters of stars that appear blue in the picture, in view of 50 cm with well resolved, thus creating an effect of carpet of stars that are intertwined with the nebulae. In short, there is nothing in the north that might resemble this amazing show!
in that area and also the supernova 1987A exploded, I think I have seen the balance because I had taken note della posizione esatta (si trova presso NGC 2044) e mi sembra di aver notato una stellina leggermente sfocata, ma per essere sicuro che fosse proprio lei dovrò informarmi meglio. In rete non sono riuscito a trovare nulla circa la possibilità o meno di osservare visualmente questo oggetto.
Anche la zona settentrionale della galassia (la porzione staccata dalla barra principale, per intenderci) è altamente spettacolare, perché ci sono grumi e trame di stelle mescolati a chiazze di nebulose sparse. Perciò questa regione che comprende NGC 1934/1948/1955/2014/2027/2030/2032/2095 eccetera, seppur meno concentrata del complesso della Tarantola, ha poco da invidiare e merita anch’essa di essere gustata per bene.
Altri objects and groups of particular interest: NGC 1727 and its surroundings, the globular cluster NGC 1763 and 1783, NGC 1770, the trio NGC 1850/1854/1858, respectively open cluster, globular nebula (find another case where we can see an object type in the same field if you can!), NGC 1876, the nebula in the shape of 'S' NGC 1910 (right to highlight this feature we need a filter, otherwise the stars surpass it), NGC 1918, the group of 1934, that of 1965, and finally the nebula NGC 2018, 2075, 2103 and 2122.
CONCLUSIONS
I hope I have provided a good guide for those who want to try a similar experience. I think that for those who are passionate deep-sky it is not just a whim but a genuine point of arrival to do at all.
All these comments I wrote them after the trip based only on memory, because during the observations by writing only the catalog numbers of objects observed, but no special notes. So do not rule out the possibility that there are errors in evaluating the degree of difficulty of the visions, and it would be interesting to compare these impressions with those of other people ... or with myself when I come back! Because it is obvious that there is a great desire to return, all 5 have just said "goodbye." I'll certainly not next year but We hope for 2011, perhaps in a different season (August or September) so you can see the constellations of the zenith at the galactic south pole that are low in April.
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