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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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05/01/2015 – Ephemeris – A talk about the Virgo Cluster of galaxies tonight and a star party

May 1, 2015 Comments off

Ephemeris for Friday, May 1st.  Today the Sun will be up for 14 hours and 14 minutes, setting at 8:47.   The Moon, 2 days before full, will set at 5:55 tomorrow morning.  Tomorrow the Sun will rise at 6:31.

Tonight yours truly will be presenting the program: The Galaxy Cluster Next Door, at this evening’s meeting of the Grand Traverse Astronomical Society at 8 p.m. at Northwestern Michigan College’s Rogers Observatory.  Following at 9 p.m. will be a star party featuring the Moon and planets Venus, Jupiter and later, Saturn.  As to the program:  There is a patch of the spring sky in the constellation of Virgo the virgin, where we are looking out the thin side of our Milky Way galaxy where there is a huge group of over a thousand galaxies astronomers have dubbed the Virgo Cluster.  Galaxy clusters are held together by the gravity of mysterious dark matter, but the clusters are expanding from all the other clusters.

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

Addendum

Messier objects

The Messier objects in the central part of the Virgo Cluster. Created with Cartes du Ciel (Sky Charts).

Virgo Cluster

Some of the galaxies in the heart of the Virgo Cluster. Created with Cartes du Ciel (Sky Charts).

04/08/11 – Ephemeris – Looking out the thin side of the Milky Way

April 8, 2011 2 comments

Friday, April 8th.  The sun will rise at 7:11.  It’ll be up for 13 hours and 7 minutes, setting at 8:18.   The moon, 3 days before first quarter, will set at 1:39 tomorrow morning.

In winter and summer we see the Milky Way crossing the sky from north to south.  In the autumn we see it cross nearly overhead from east to west.  In the spring, especially next month the Milky way is barely visible low in the north.  The Milky Way circles the sky as a great circle.  It is what we see of our own galaxy.  It is a spiral galaxy 100,000 light years in diameter and less than 5,000 light years thick where we are.  So in the spring we look out the thin side of our galaxy.  The stars are sparser than in other parts of the sky, the constellations generally are larger.  The really cool part is that in telescopes we can see other galaxies, other Milky Ways beyond.  In the spring we have a huge cluster of thousands of galaxies out there about 50 million light years away.

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

Addendum

Looking out the thin side of the Milky Way

Looking out the thin side of the Milky Way. Created using Cartes duCiel

This is the entire dome of the sky on May 15th at 11 p.m.   Note the Milky Way ringing the horizon.  The red dots are galaxies, the blue and gray dots are star clusters in our galaxy, the green ones are nebulae, also in our galaxy.