After several attempts at NGC 6118, the most difficult object in the Herschel 400, and nothing but failures so far, tonight, my 4" TV-102 Light Cup decided to tackle NGC 6380, which is reputed to be the 2nd ;-) most difficult object in the Herschel 400. The Sky and SEDS listed this open cluster at magnitude 15! Whoa, wait justa dogon
minute, I told the Light Cup; this is insane. But the Light Cup's research dugged up some observation that the OC is around mag 9.6. OK, why not. The LM around the area was only 5.0 with sky glow and light pollution from the south. Armed with detail zoomed in printed chart and photo mirror reversed to match the view, the Light Cup and
I spent one hour on this object alone!
http://www.seds.org/~spider/ngc/ngcdss.cgi?obj=NGC!6540&r=18:06.3&d=-27:49&e=J2000&h=15&w=15&f=GIF&c=none
Please import it into MS Paint and mirror reverse the image for the observation below.
I can see why this object is the 2nd most difficult because it was hard to find despite having a detail printed chart. One look at the photo should convince you of this as well :-(. After the star field has been located, it was no where to be seen at 22x, 30x, 44x, 73x! The Light Cup got really worry but switched its eyeball to the 8mm TV Radian (the Planetary Nebula Nabber) at 110x and viola, hooked this
fine open cluster into its OTA. The view is much better a 146x (6mm Radian) showing the asterism of 6 stars at the lower left hand corner of the photo: GSC 6850:3231, GSC 6850:3442, GSC 6850:1481, GSC 6850:3253 and a mag 8.9 HD 165180. The OC is enclosed by a triangle made up of the stars: HD 165180, GSC 6850:2111 and a dim GSC 6850:1614. Some stars could be seen inside the OC with averted
vision. The shape looks irregular with brighter center. This bright center is probably the bright group of stars near the center of the photo. The very best view at 176x (5mm Radian) which is incredibly brighter than at 146x. 2 more dimmy stars popped in: GSC 6850:2110 and GSC 6850:1199. Some stars in the central portion of the OC can
now be seen with direct vision. I would estimate that NGC 6540 is much brighter than mag 15 but dimmer than mag 9.6.
I also noticed a group of stars that looked like another loose OC as seen at the bottom of the photo. Consulting The Sky, it doesn't appear to be any open cluster in that area.
Checking with The Sky software later, I found that the OC isn't plotted where I saw it! I carefully sketched the OC and the stars during the seesion; besides the photo doesn't lie ;-). For you guys who are H400 veterans, I would appreciate any comment.
I recommend this very challenging open cluster to everyone and especially to those who conceived of OC as being dreary and would surely alter his/her notion as being sweaty (meaning working up the sweat just to see it ;-).
Ron B[ee]
minute, I told the Light Cup; this is insane. But the Light Cup's research dugged up some observation that the OC is around mag 9.6. OK, why not. The LM around the area was only 5.0 with sky glow and light pollution from the south. Armed with detail zoomed in printed chart and photo mirror reversed to match the view, the Light Cup and
I spent one hour on this object alone!
http://www.seds.org/~spider/ngc/ngcdss.cgi?obj=NGC!6540&r=18:06.3&d=-27:49&e=J2000&h=15&w=15&f=GIF&c=none
Please import it into MS Paint and mirror reverse the image for the observation below.
I can see why this object is the 2nd most difficult because it was hard to find despite having a detail printed chart. One look at the photo should convince you of this as well :-(. After the star field has been located, it was no where to be seen at 22x, 30x, 44x, 73x! The Light Cup got really worry but switched its eyeball to the 8mm TV Radian (the Planetary Nebula Nabber) at 110x and viola, hooked this
fine open cluster into its OTA. The view is much better a 146x (6mm Radian) showing the asterism of 6 stars at the lower left hand corner of the photo: GSC 6850:3231, GSC 6850:3442, GSC 6850:1481, GSC 6850:3253 and a mag 8.9 HD 165180. The OC is enclosed by a triangle made up of the stars: HD 165180, GSC 6850:2111 and a dim GSC 6850:1614. Some stars could be seen inside the OC with averted
vision. The shape looks irregular with brighter center. This bright center is probably the bright group of stars near the center of the photo. The very best view at 176x (5mm Radian) which is incredibly brighter than at 146x. 2 more dimmy stars popped in: GSC 6850:2110 and GSC 6850:1199. Some stars in the central portion of the OC can
now be seen with direct vision. I would estimate that NGC 6540 is much brighter than mag 15 but dimmer than mag 9.6.
I also noticed a group of stars that looked like another loose OC as seen at the bottom of the photo. Consulting The Sky, it doesn't appear to be any open cluster in that area.
Checking with The Sky software later, I found that the OC isn't plotted where I saw it! I carefully sketched the OC and the stars during the seesion; besides the photo doesn't lie ;-). For you guys who are H400 veterans, I would appreciate any comment.
I recommend this very challenging open cluster to everyone and especially to those who conceived of OC as being dreary and would surely alter his/her notion as being sweaty (meaning working up the sweat just to see it ;-).
Ron B[ee]
