M3 on May 06, 2006
M3 (NGC 5272). Total integration time 160×10.0 sec = 26.7 min. The extent of this image is shown by the box on the image of M3 in the May 3 observing session. M3 is 10.4 kpc from the Sun. The V magnitude of the horizontal branch is 15.7.
M53, M3, and NGC 4631 on May 03, 2006
M53 (NGC 5024). Total integration time 122×15.0 sec = 30.5 min. M53 is 17.8 kpc from the Sun. The V magnitude of the horizontal branch is 16.8. This is the inaugural image of my new Meade DSI Pro II CCD camera.
M3 (NGC 5272). Total integration time 149×11.3 sec = 28 min. The box shows the extent of the image of M3 shown in the May 6 observing session. M3 is 10.4 kpc from the Sun. The V magnitude of the horizontal branch is 15.7.
NGC 4631. Total integration time 243×15.0 sec = 61 min.
h Per, NGC7331, M56, and NGC281 on September 28, 2005
h Per on September 28, 2005. Prime focus (f/8.0). Total integration time 164×8.53 sec = 23 min. This is central core of h Per, an open cluster of about 320 stars that is stunning in a pair of binoculars or at low magnification in a telescope. It is about 2,230 pc distant.
NGC 7331 on September 28, 2005. Prime focus (f/8.0). Total integration time 430×8.53 sec = 61 min.
M56 (NGC 6779). Total integration time 424×8.53 sec = 60 min. This globular cluster lies roughly 9,800 pc distant. The horizontal branch (HB) of this cluster is at V magnitude 16.3, which is the magnitude at which large numbers of cluster stars become visible.
NGC 281 on September 28, 2005. Prime focus (f/8.0). Total integration time 209×8.53 sec = 30 min. NGC 281 is the nebulosity associated with the open cluster IC 1590
Veil Nebula, M92, and NGC6229 on August 24, 2005
NGC 6992 (Veil Nebula) on August 24, 2005. Prime focus (f/8.0). Total integration time 486×8.53 sec = 69 min. This is a small section in the NNE part of the Veil Nebula.
NGC 6229. Total integration time 446×8.53 sec = 63 min. This is a faint globular cluster, roughly 91,000 to 103,000 light years distant — clear across the Galaxy from us. The V magnitude of the horizontal branch is 18.0, so we’re mainly seeing the brightest cluster members in this image. (The brightest cluster star is V=15.5.) Note the faint "stars" NE of foreground stars HD151651 and HD151689. I suspect these are due to internal reflections from the minus-violet filter (and perhaps the CCD cover glass).
M92 (NGC 6341). Total integration time 185×8.53 sec = 26 min. This globular cluster lies 24,000 to 33,000 light years distant. The core in this image is overexposed. The horizontal branch (HB) of this cluster is at V magnitude 15.2, which is therefore the magnitude at which large numbers of cluster stars become visible. This HB magnitude is only slightly brighter than the brightest star in NGC 6229!
M29 on August 2, 2005
M29 (NGC 6913). Total integration time 316×8.53 sec = 45 min. This is a sparse open cluster of about 80-100 stars (integrated magnitude 6.6) whose brightest star is mag. 9.0. It lies 4380 light years distant.
M71 on July 31, 2005
M71 (NGC 6838). Total integration time 390×8.53 sec = 55 min. This is a relatively sparse globular cluster whose brightest star is mag. 12.1 and whose horizontal branch is at mag. 14.5. It lies 13,000 light years distant.
M13, M27, M57, and NGC 5466 on 17 June 2005
M13. Total integration time 137×8.53 sec = 19.5 min.
M27 (the Dumbbell Nebula). Total integration time 419×8.53 sec = 60 min.
M57 (the Ring Nebula). Total integration time 280×8.53 sec = 40 min. The V magnitudes shown are from photometry of M57 field stars taken by Arne Hendon (USNO-Flagstaff). See Brian Skiff’s page on M57 field star photometry for more information.
NGC 5466 on June 17, 2005. Prime focus (f/8.0). Total integration time 349×8.53 sec = 50 min. This is a faint, sparse globular cluster, roughly 52,000 light years distant.