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Ephemeris Extra – Autumn telescopic wonders

November 6, 2016 Comments off

This is an updated article I wrote from the October 1998 issue of the Grand Traverse Astronomical Society’ newsletter the Stellar Sentinel

18 years ago Judy, my late wife, and I bought a telescope from Enerdyne. Officially it was Judy’s telescope and is a Celestron 11 inch (280 mm) Star Hopper Dobsonian. After over 20 years of relying on the telescopes at the Lanphier and Rogers observatories, we felt the need again for a personal backyard telescope again. This was also brought home by the appearance of the comets Hyakutake and Hale-Bopp in the 1996 and 1997.

Though large in diameter, the telescope has a focal length of 49.5 inches (1260 mm), much closer to the telescopes I’ve made and used in the past, and a third to a half the diameter of the C14s at the observatories above. So the scope gives bright low power views of galaxies and nebulae. The diameter allows the resolution of some globular clusters. I was also quite pleasantly surprised at the scope’s ability to see detail on Jupiter and Saturn. Jupiter’s Great Red (currently a pale pink) Spot and on Saturn: a cloud band, ring shadows and Cassini’s Division.

Soon after obtaining the telescope I surveyed the dim wonders of the autumn sky beyond the solar system. Here are the results:

Galaxies

  • M31, M32 and M110 Better known as the Great Andromeda Galaxy and its companion galaxies, the view is made to order for the smaller telescope. M31’s glowing nucleus spans the eyepiece field. The galaxy is larger than out own and lies at a distance 2.5 million light years. The brightness falls off sharply along the north side of it’s elliptical minor axis. The nearly spherical M32 is seen nearby, while the faint elliptical galaxy M110 is barely visible on the other side of M31. I used to know M110 only as NGC205.  It was added to Messier’s list in 1967, 11 years after I first observed the galaxy.
    A note about The M designations.  They are from a catalog started by French comet hunter Charles Messier (1730-1817) who made a list of fuzzy objects in the sky that could be confused as being comets because they didn’t move against the stars.   He officially discovered or co-discovered a dozen comets.  As can be seen by the inclusion Of M110, it has been extended by other astronomers.
  • M33 The Triangulum galaxy is seen nearby off the point Triangulum is about as close as M31, but smaller than M31 with a small nucleus and large faint disk. It has a very low surface brightness and requires a dark sky.
  • M74 Is located in Pisces near Aries. It is a face-on galaxy like M33 but a lot smaller and fainter. I saw no central condensation.
  • M77 is a different story, a galaxy with a bright nucleus. M77 is located is Cetus located just below the head of the monster or tail of the whale, however you see him.

Globular star clusters

  • M15 is a globular cluster found by extending the nose of Pegasus. The 11 inch telescope could resolve the cluster’s outer stars. It was a smaller, dimmer version of M13, the grand globular in Hercules.
  • M2 is a more distant globular located due south of M15 and at an equal declination as (α)Alpha Aquarii or Sadal Melik. It earns its inclusion as Messier’s object number 2, for it looks for all the world like a tailless comet. On a second look at it the 11 inch could resolve a few stars.
  • M30 seems the same size as M2 and located farther south just right of the star (ζ)Zeta Capricorni. However the 11 inch can resolve a handful of its brighter stars.

As we move outward from the galactic center in Sagittarius the globular clusters thin out dramatically. The next Messier globular is located in Lepus the hare below Orion a winter constellation.

Open or galactic clusters

  • M34 is a large but sparse open or galactic star cluster located just west of the star Algol in Perseus.
  • M103 is a faint triangular-shaped cluster located just east of the star (δ)Delta Casseopeiae. The triangular arrangement of its stars reminds me of a smaller version of the Beehive Cluster (M44) in Cancer.
  • M52 is a faint but populous cluster located between Cassiopeia and Cepheus.
  • The Double Cluster is a great view in a low power eyepiece. The two clusters do not have Messier designations. But they do have NGC numbers: 869 and 884. NGC is the “New General Catalog” and is not so new. It’s over 100 years old.
  • M45 or the Pleiades is best seen in a pair of binoculars. Also known as the Seven Sisters, the Pleiades is close as star clusters go at 400 light years.
  • Melotte 25 or Collinder 50:  The Hyades, the face of Taurus the Bull, is the closest star cluster of all at about 153 light years. Sparse and big, it is almost too large to view in a pair of binoculars. The Hyades is the key to finding distances to the ends of the universe. It is close enough to get good parallax data for triangulation. Its many stars of known brightness and distance can be matched to other star clusters beyond the reach of the parallax method to ascertain their distances.

M76 is the only planetary nebula in our group. Called the Little Dumbbell Nebula or the Barbell Nebula, it has a shape of one of those Milk Bone dog biscuits.

Autumn telescopic wonders


A star chart covering the autumn constellations and the objects described in this article. In Andromeda (And) the overprinted captions are for M31 and M32. The Double Cluster is not shown, not being a Messier object. It’s approximately half way between the northernmost star of Perseus (Per) and M103 in Cassiopeia (Cas). The article doesn’t cover the Messier objects M35, 26, 37 ,38, 42/3 and 78. Which I may do for winter. The star chart was created using the author’s program LookingUp.

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08/30/2016 – Ephemeris – One of the many wonders in the steam from the Teapot

August 30, 2016 Comments off

Ephemeris for Tuesday, August 30th.  The Sun will rise at 7:03.  It’ll be up for 13 hours and 18 minutes, setting at 8:22.  The Moon, 2 days before new, will rise at 6:14 tomorrow morning.

Yesterday I talked about the Teapot pattern of stars low in the south these evenings that’s better represented in the stars for us moderns than a centaur with a bow and arrow called Sagittarius.  The teapot, spout to the right is appearing to begin to pour its contents on the southern horizon, with steam appearing above the spout.  That steam is the Milky Way.  In that steam, above the spout is a small horizontal line of light.  Binoculars or a telescope will reveal a star cluster there and more haze.  That haze is the Lagoon Nebula, also known to astronomers as M8, that spawned that star cluster.  This is the brightest nebula of the summer sky, and is 5 to 6 thousand light years away, in the next spiral arm inward in our Milky Way galaxy.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Lagoon Nebula

The Sagittarius Teapot showing the location of the Lagoon Nebula that is visible to the naked eye. Photo Credit Bob Moler.

Objects designated by the letter M are known as Messier objects, from a list made by Charles Messier who was an astronomer at the Paris Observatory at about the time of the American Revolution.  Messier was interested in discovering comets, which when the first become visible are fuzzy blobs without tails.  A comet makes itself known by moving against the stars.  The objects on the list don’t move against the stars, being with the stars or beyond, which we call deep sky objects.  So it’s a list of objects not to bother with, because they aren’t comets.  Today we use his list or catalog of objects as some of the finest objects in the heavens.