Tag Archives: Sky & Telescope

Sky-Watcher’s Stargate Truss-Tube Dobsonian Telescopes

Sky-Watcher USA
310-803-5953 ext. 306

Sky-Watcher unveiled its Stargate Truss-Tube Dobsonian Telescopes at NEAF. These large 18- and 20-inch f/4 reflectors (starting at $5,999) are constructed around conical fused-borosilicate primary and cellular secondary mirrors with 94% reflective aluminum coatings. The modular truss design divides the total weight of each scope into manageable sections that assemble quickly in the field. The base model includes a 2-inch dual-speed Crayford focuser, 9×50 finder scope, as well as 28- and 10-mm LET eyepieces. Additional accessories include three 2.3 lb. counterweights, a truss shroud, and tool-free truss clamps. Both scopes are also available with motorized Go To and a SynScan hand controller at additional cost, featuring dual encoders that permit manual slewing without losing alignment. See manufacturer’s website for additional details.

(more…)

Palling Around With the Palomar Globular Clusters

The intriguing Palomar globular clusters will challenge observers with modest to large telescopes, while providing a satisfying ramble around the galactic halo. Seize the upcoming dark of the Moon to make their acquaintance.

Keeps On Ticking

Scott Kardel, public affairs coordinator for Palomar Observatory, stands at the 48-inch Schmidt camera used for the first Palomar Observatory Sky Survey in the 1950s.
Sky & Telescope archives

Back when the Palomar clusters were discovered, a Coke cost a nickel and a quarter would buy you a burger at a Mom-and-Pop diner. We currently know of about 157 globular clusters in Milky Way galaxy, 15 of which were discovered on the survey plates of the first Palomar Observatory Sky Survey (POSS) in the 1950s.

(more…)

Sketching Celestial Observations

Why, and how, you should sketch your observations through a telescope.

A sketch of the Perseus Double Cluster (NGC 884 and NGC 869). D. Rennie

A sketch of the Perseus Double Cluster, NGC 884 and NGC 869.
D. Rennie

In the late-1990s, I wrote an essay for a literary journal and cited two quotes: one from an 1851 anonymous French book collector (“Owning a book puts it in your possession, but only reading a book makes it yours”) and the second from renowned literary critic Edmund Wilson (“No two persons read the same book”) Both quotes relate to why I made sketching a regular component of my observing routine.

When you locate and observe a celestial object, it produces a visual experience and another checked box on your “objects seen” list. You move on to the next target, and just as quickly to the one after that. The impression of the object you observed only minutes ago is already dim and quickly being forgotten.

(more…)