Dear star lovers,
Sagittarius situates at the very heart of our galaxy and it contains many deep sky objects. Recently "Astronomy" magazine listed 40 "popular" deep sky objects inside this constellation and, given that we are at the right time of the year and the appearance of fine weather, it is desirable to carry out a mini marathon to view through all these 40 objects within one night. Notice that not all of these objects are easy - some of them are very difficult to be detected visually, even for a 16 incher. The bigger the telescope, the better will be the result.
Out of the 40 objects listed two failed to be visible inside the 16 incher due to their too low brightness. ( NGC6537 "red spider" and NGC6822 the Bernard's galaxy )
NGC6440 2106 Globular cluster. Small, rather bright core, stars unresolved.
NGC6309 2110 Planetary nebula, the "box". Rather bright, very small in size. Approximately an elongated bubble shape. No central star was observed.
M23 2117 Open cluster. Remarkable! Bright, busy, you were watching numerous stars over another busy star background. Very nice view.
M20 2122 Trifid nebula. Faint, but the three cracks re just plainly visible.
NGC6520 2128 Open cluster, the "castaway". Small in size. A nebula like star cluster on a rich background. Averted vision resolved individual stars.
NGC6522 2133 Globular cluster. Middle in size, rather bright but with no definite core observed. Stars unresolved.
M8 2135 The Lagoon nebula. Big, majestic, always a showpiece in sky. The bright and textured nebulosity together with the star cluster within created an unforgettable scene in one's heart.
M21 2139 Open cluster. Middle in size, bright but not very busy. Still a nice view to look at.
NGC6544 2147 Globular cluster. Middle size, rather bright and with no noticeable core. However averted vision completely resolved it into stars.
NGC6553 2154 Middle sized, fairy bright but with no definite core. Stars unresolved.
NGC6569 2200 Globular cluster. Small sized, fairy bright, slightly brigher core and stars were unresolved.
NGC6558 2203 Globular cluster. Small, rather bright, no definite core and stars unresolved.
NGC6559 2209 Cat's claw nebular. Very faint nebula surrounding a pair of double star. Middle sized.
IC1274 2215 Cat's claw nebular. Extremely faint, only seen by averted vision.
NGC6569 2200 Middle sized, rather bright and have a slightly brighter core. Stars unresolved.
NGC6589 2222 Nebula. Medium in size, bright nebulosity surrounding a bright star.
NGC6590 2222 Nebula. Medium in size, bright nebulosity surrounding a bright star. Same field with NGC6589.
M18 2227 Open cluster. Bright, medium in size but contains only around a dozen stars. Not attractive.
M17 2229 Omega nebula. Bright, situated in a rich star background. Well textured and always a delighted view to look at. The "duck" shape is being very well defined.
NGC6624 2233 Globular cluster. Small in size, bright core but stars unresolved.
M28 2234 Globular cluster. Spectacular. Middle sized but with bright core. Stars fully resolved.
M24 2240 Sea of stars with dark nebulae fully embedded.
B92 2240 Dark nebula. Within M24, dark regions are seen locking off stars background.
M69 2243 Small, bright core but stars were only resolved by averted vision.
NGC6638 2245 Open cluster. Small, rather bright, core easily seen.
NGC6642 2247 Globular cluster. Small, non-circular shape with no definite core.
NGC6645 2250 Open cluster. Fairy bright, medium to big size, rather busy. The most interesting thing was that there was a "hole" observed at center of the cluster.
NGC6652 2253 Globular cluster. Small sized, rather bright, core easily seen but stars were unresolved.
M22 2256 Globular cluster. Majestic! Big, bright, very bright core withy stars resolved down to core.
M25 2259 Open cluster. Very big, very bright and rather busy. A nice view to look at.
M54 2301 Globular cluster. Small sized but with very core. Stars were unresolved.
NGC6716 2304 Open cluster. Medium sized, bright but contains only about one dozen stars.
NGC6717 2309 Globular cluster. Very small but rather bright, next to a very bright star, averted vision reveal a central core.
NGC6723 2312 Globular cluster. Rather big, rather bright but with no definite core. However stars were nearly fully resolved. Nice view.
M70 2315 Globular cluster. Small, bright core, fully resolved under averted vision.
M55 2317 Globular cluster. Big, bright, rather diffuse, fully resolved.
NGC6818 2230 Planetary nebula. The "little gem". A bright small blue bubble with no central star observed.
M75 2332 Globular cluster. Small in size, bright core and stars were unresolved.
It took around 2.5 hours to complete the marathon. It was not at all easy because the time that Sagittarius remains in the favorite position is not long ( in PTC ). Hopefully we are going to carry out another marathon in Scorpius, where again a lot beautiful deep sky objects situate.
Best regards
Chan Yuk Lun
8 August 2013.
Sagittarius marathon at PTC.
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Chanlunlun
- 夸克星
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- 註冊時間: 週四 09 10月, 2003 21:06
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