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03/17/2017 – Ephemeris – When Ireland had the largest telescope in the world

March 17, 2017 Comments off

Ephemeris for St. Patrick’s Day, Friday, March 17th.  The Sun will rise at 7:50.  It’ll be up for 12 hours even, setting at 7:51.  The Moon, 3 days before last quarter, will rise at 1:01 tomorrow morning.

In the 19th century Ireland laid claim to having the largest telescope in the world.  It was a reflecting telescope with a mirror diameter of 72 inches.  It was built by William Parsons the Third Earl of Rosse.  The base of the telescope tube rested in a pit between two massive walls and could only look in a north-south direction.  It saw first usage in 1847.  The telescope was called the Leviathan of Parsonstown, and was in use until 1890.  Mirrors in those days was made of a silvery alloy called speculum.  Two mirrors were used alternately because speculum tarnished.  The mirror not in use would have to be re-polished and swapped in from time to time.  It was the largest telescope until the 100 inch at Mt. Wilson was put in service in 1917.

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

Addendum

Leviathan of Parsonstown

The 72 inch Leviathan of Parsonstown. source: http://www.klima-luft.de/steinicke/ngcic/persons/rosse3.htm

M51 drawing

A drawing of the Whirlpool Galaxy, M51 (NGC 5194 & 5195) by Lord Rosse with the 72 inch telescope. Public Domain.

M51 photo

The Whirlpool Galaxy, M51. Credit Scott Anttila.

The Whirlpool Galaxy is the only galaxy that I’ve actually visually seen spiral arms on.  It was seen using a Celestron 14″ telescope at Northwestern Michigan’s Joseph H. Rogers Observatory.  That was a looong time ago.

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01/06/2017 – Ephemeris – Telescope Clinic tonight at the NMC Observatory

January 6, 2017 Comments off

Ephemeris for Friday, January 6th.  The Sun will rise at 8:19.  It’ll be up for 8 hours and 59 minutes, setting at 5:18.  The Moon, 1 day past first quarter, will set at 2:34 tomorrow morning.

If you’ve received a telescope for Christmas and are having trouble setting it up, or have an unused one in a closet, basement or attic, bring them to Northwestern Michigan College’s Rogers Observatory tonight at 8 p.m.  The Grand Traverse Astronomical Society will be holding their annual telescope clinic to help you understand and use your telescope.  The clinic will extend through the period that will be set aside for a star party if it’s clear, to test the telescopes and show the owners how to use them.  Like anything telescopes take some time to learn how to use them and find celestial objects.  It took me 15 minutes to find Saturn with a telescope the first time I tried, and I knew where it was in the sky.  The observatory is south of Traverse City on Birmley Road.

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

In Memorium

Emmett Holmes

Emmett Holmes passed away last night (January 5th, 2017) after a long ordeal in attempting to have stem cells from his sister infused into his blood to rebuild his bone marrow. We at the Grand Traverse Astronomical Society knew him for a few short years, but in the time we benefited greatly from his expertise with telescopes and, helping out with star parties.. In the picture is his 13″ telescope with its distinctive tube that he built. Just recently he was elected to the Board of Directors of the Society.
We at the GTAS express our condolences to his wife Karen and the rest of his family. Emmett, rest in peace.

09/03/2015 – Ephemeris – Jewels in the shield

September 3, 2015 Comments off

Ephemeris for Thursday, September 3rd.  The Sun will rise at 7:07.  It’ll be up for 13 hours and 9 minutes, setting at 8:16.   The Moon, 2 days before last quarter, will rise at 11:26 this evening.

The teapot pattern of stars that is the constellation of Sagittarius lies at the southern end of the Milky Way this evening. It appears that the Milky Way is steam rising from the spout.  The area above Sagittarius in the brightest part of the Milky Way is the dim constellation of Scutum the shield.  Don’t bother looking for the stars that make up the constellation; what’s important is the star clouds of the Milky Way.  Scan this area with binoculars or small telescope for star clusters and nebulae or clouds of gas.  In binoculars both clusters and nebulae will appear fuzzy, but a small telescope will tell most of them apart.  Even if you’ve never been able to find anything in your telescope, you’ll find something here.

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

Addendum

Scutum

Scutum between Sagittarius below and Aquila above at 10 p.m. September 3, 2015. Created using Stellarium.

Star hopping in Scutum

How to find the three brightest deep sky wonders around Scutum by star hopping. Created using Stellarium, annotated by myself.

Star hopping is a method to find objects from familiar star patterns.  At the top my method to find M11, the wild duck cluster is to locate the three stars at the tail of Aquila the Eagle and follow them to M11.  M11 takes a little bigger telescope to resolve.  I remember having trouble resolving it is a 5″ telescope.  It looks like a triangular cluster with all the stars of the same dimness except one brighter one.

At the bottom of Scutum, I locate that distinctive 5 star group circled.  Directly west is M16, the Eagle Nebula and star cluster.  The star cluster is easy to spot, the nebula is hard.  The Hubble space telescope made the nebula famous in the 1990’s as the Pillars of Creation.

Below and west is M17, the Omega Nebula, or the Swan Nebula.  To me it looks like a swan swimming or a check mark of nebulosity.  The associated star cluster is much less noticeable.

Happy star hopping.

05/29/2015 – Ephemeris completes 40 years on the air

May 29, 2015 Comments off

Ephemeris for Monday, June 1st.  Today the Sun will be up for 15 hours and 20 minutes, setting at 9:21.   The Moon, 1 day before full, will set at 6:17 tomorrow morning and tomorrow the Sun will rise at 6:00.

We’ll start Ephemeris’ 41st orbit of the Sun by looking at the skies of June.  There’ will be a lot of sun in June and very little night.  The daylight hours will increase a bit from 15 hours and 20 minutes today to 15 hours and 34 minutes on the 21st, retreating back to 15 hours 31 minutes at month’s end.  At this time of the year the sunset times for Ludington, Interlochen, Petoskey and Mackinaw City are very nearly the same.  However the sunrise times are at their most divergent.  With Ludington’s sunrise being 14 minutes later than Mackinaw City’s.  The altitude of the sun above the southern horizon at local noon will hover around 68 to 69 degrees.  Local noon, when the sun is actually due south will occur at about 1:43 p.m.  Here’s what we’ve been waiting for:  Summer will start on the 21st at 12:38 p.m.

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

Addendum

This is my article in the June Stellar Sentinel, the monthly newsletter of the Grand Traverse Astronomical Society

At the end of May I will have completed 40 years of the short program on Interlochen Public Radio (IPR) I call Ephemeris. The first airing was June 1st 1975. It currently airs twice each week day at 6:49 a.m.** on their news stations, and at 6:59 a.m.** on their classical music stations. This article isn’t about Ephemeris, but what has transpired in the last 40 years. It’s kind of sobering to realize that 40 years is approximately 10% of the span of 406 years since Galileo first turned his crude telescope to the night sky. Over the next year I’ll look at what has been happening in astronomy and space in those 40 years. This time I’ll look at some telescope advances in that time.

In 1975 the largest optical telescope in the world was the Hale 200 inch (5 meter) telescope* on Mount Palomar, today the Keck I telescope and its twin Keck II on Mauna Kea in Hawai’i are among the largest in the world with 10 meter diameter mirrors. Keck I saw first light in 1990, while Keck II saw its first light in 1996. They share the peak with two 8 meter telescopes: Gemini North and Subaru, among other large scopes. The Thirty Meter Telescope (TMT) is about to be built up there pending the clearing up of a dispute with native Hawaiians who consider the mountain sacred.

Actually the Kecks have been edged out by the Gran Telescopio Canarias, in the Canary Islands with a 10.4 meter mirror, which saw first light a few years ago. Not to be outdone, the European Southern Observatory, a consortium of 13 European nations have established a beachhead in the Chilean Andes and are building the European Extremely Large Telescope (E-ELT). Its segmented mirror will span 39.3 meters (1,550 inches), nearly eight times the diameter of the Hale telescope, and is expected to see first light in 2024. If Ephemeris and I will be around another 10 years, we’ll see that too.

Many of the existing large telescopes have been shown up by NASA’s most popular satellite, the Hubble Space Telescope (HST) which has only a 2.4 meter (94.5 inch) mirror. Telescope placement is like real estate: Location, location, location. The higher the better to beat the bane of telescope viewing atmospheric turbulence. Nearly 400 miles altitude in orbit solves that problem nicely. The next generation space telescope is to be launched in three years. It’s the James Webb Space Telescope (JWST), named for an Apollo era NASA administrator. It will be launched by an ESA Ariane 5 rocket to the Earth-Sun L2 point a million miles opposite the direction of the Sun. It will operate in the infrared.

Not to be outdone by Hubble, ground based astronomers have found a way to combat atmospheric turbulence, or “bad seeing” as we term it: It’s called adaptive optics. Ever see those time-lapse videos of the Keck and other observatories shine lasers skyward. These are tuned to the wavelength that excites sodium atoms in the atmosphere above 50 kilometers to produce an artificial star. By deforming the telescope mirror or mirror segments to straighten out the artificial star’s light the atmospheric seeing can be improved by a factor of 16 or better. This technique works better in the infrared whose wavelengths are longer than visible light.

Our atmosphere is relatively transparent at wavelengths that happen to be at the Sun’s peak output. That is where evolution has given us the ability to see in. However to use an acoustic analogy, we are doomed to hear the cosmic symphony by listening to a single octave on a piano that stretches in a mile in either direction from middle C.

In 1975 radio astronomy was beginning to work with multiple telescopes to produce radio interferometers that spanned the continent to produce the effect of a single telescope of the width of the array of many telescopes. These arrays have now spanned oceans, and even into space. These interferometers rival and surpass the resolution of optical telescopes. A prime goal is to resolve the black hole in the center of the Milky Way, something that can’t be seen invisible light, which can’t penetrate the gas and dust along the 26,000 light year path to the center of our galaxy.

Today there are neutrino telescopes underground, X-ray telescopes and Gamma Ray telescopes orbiting the Earth, an armada of spacecraft orbiting and studying the Sun. Also techniques and instruments have been refined, so that when once the idea of detecting planets around other stars was thought to be a dream for the future, we’ve been discovering them by the thousands over the last 20 years. Even amateur astronomers can do it now.

In the 45 seconds I have to devote to astronomical topics after the sunrise, sunset and lunar phase information in an Ephemeris program I cannot delve deeply into the wonders that modern astronomy brings. But I can give a taste, and provide the key to the heavens to just go out and experience the wonder of the universe that is the night sky as seen from our own back yards.

* I forgot about BTA-6 in the Caucasus Mountains in the then Soviet Union, a 6 meter telescope that saw first light in late 1975, so I guess I was still correct on the Ephemeris launch date.  It has a history of problems and was never really able to fulfill its promise for a number of reasons.  It beat out the Hale telescope by 38 inches.  It did pioneer the alt-azimuth mount that all large telescopes now use.

** Correction (June 4):  These are the corrected times.  I was an hour too late.   Thanx and a tip of the old observers cap to Emmett Holmes for the heads up.

01/02/2015 – Ephemeris – Telescope Clinic tonight in Traverse City

January 2, 2015 Comments off

Ephemeris for Friday, January 2nd.  The sun will rise at 8:20, the latest sunrise of the year.  It’ll be up for 8 hours and 53 minutes, setting at 5:13.   The moon, 2 days before full, will set at 6:38 tomorrow morning.

Did you or someone in your family get a telescope for Christmas, or have one in a closet or attic because you don’t know how to put it together or operate?  Or maybe you are trying to figure out which one to buy.  Well, tonight’s your night.  The Grand Traverse Astronomical Society will host a telescope clinic at Northwestern Michigan College’s Rogers Observatory on Birmley Road, south of Traverse City starting at 8 p.m.  Telescope experts from the society will help you set up your telescope and give you observing tips.  So bring ’em if you’ve got ’em.  If it’s clear, at 9 p.m., there will be a star party to try out your telescope, or try them out on the lights of Traverse City.  Can’t make it?  We can help you after any meeting.

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

Addenda

Remember the Quadrantid meteor shower tomorrow evening and into Sunday morning:

The moon will interfere with the meteor shower, so only the brightest will be visible.  The radiant will rise from the northeast.  The radiant will be nearly overhead at the start of twilight.  On a dark night up to 120 meteors per hour may be seen according to the International Meteor Organization.

Quadrantid meteor shower radiant at 1:30 a.m.

 

The Earth will reach perihelion Sunday.
This is the closest the Earth gets to the Sun in its orbit this year.  The Sun will be 91,402,000 miles or 147,096,000 kilometers away at around 1 a.m. January 4th, 2015 EST or 6 hr UT January 5th 2015.  It makes winter the shortest season because the Earth is moving its fastest during perihelion.  It’s only by a few days.  And in northern Michigan where it seems that winter overlaps half of fall and spring besides, that few days difference is buried under snow.

09/02/2014 – Ephemeris – Viewing the first quarter Moon

September 2, 2014 Comments off

Ephemeris for Tuesday, September 2nd.  The sun will rise at 7:06.  It’ll be up for 13 hours and 11 minutes, setting at 8:17.   The moon, at first quarter today, will set at 12:52 tomorrow morning.

Tonight on the moon there are some very prominent craters on the terminator or sunrise line that’s cutting the moon in half.  From the top or north of the moon there’s Plato, which is also called a ringed plain because it has a flat floor.  South of there is Eratosthenes, at the end of the arc of the Apennines mountain chain.  At the south or bottom end of the moon are two other of my favorite craters.    First is the crater Tycho, that doesn’t look spectacular now, but will when the Moon is full with its rays of ejecta crossing a long way across the face of the moon.  A little bit farther south, partially entering sunlight is the large crater Clavius.  On my blog, bobmoler.wordpress.com, I’ll illustrate what the Moon’s image looks like in different types of telescopes.

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

Addenda

The moon tonight

The Moon tonight at 9 p.m. (September, 2, 2014). Created using Virtual Moon Atlas.

Image orientation in telescopes

The orientation of what one sees in an astronomical telescope depends on the type of telescope and the placement of the eyepiece.  The orientations shown are for observers in the northern hemisphere.  For the images below the moon shown is due south.

Erect image

The orientation of the Moon as seen with the naked eye, binoculars, spotting scopes and telescopes with an erecting eyepiece.

Mirror image

The orientation of the Moon as seen in a refractor or a Schmidt-Cassigrain or similar type reflector with a diagonal at the eyepiece end, and the eyepiece pointing up. This is a mirror image due to an odd number of mirror reflections in the telescope.

Inverted mirror image

The orientation of the Moon as seen with a refractor or Schmidt-Cassigrain and diagonal with the eyepiece oriented horizontally. It is a n inverted mirror image.

Inverted Moon

The orientation of the moon through a Newtonian reflector or a refractor without an eyepiece diagonal. It is an inverted image, an image rotated 180 degrees.

For southern hemisphere observers for these images to work the moon would be due north and all the images would have to be upside down.

Correction 09/02/2014 11:07 p.m.

All images created using Virtual Moon Atlas.

 

03/17/2014 – Ephemeris – When Ireland had the world’s largest telescope

March 17, 2014 Comments off

Ephemeris for St. Patrick’s Day, Monday, March 17th.  The sun will rise at 7:51.  It’ll be up for 11 hours and 59 minutes, setting at 7:51.   The moon, 1 day past full, will rise at 9:11 this evening.

In the 19th century Ireland laid claim to having the largest telescope.  It was a reflecting telescope with a mirror diameter of 72 inches.  It was built by William Parsons the Third Earl of Rosse.  The base of the telescope tube rested in a pit between two massive walls and could only look in a north-south direction.  It saw first usage in 1847.  The telescope was called the Leviathan of Parsonstown, and was in use until 1890.  Mirrors in those days was made of a silvery alloy called speculum.  Two mirrors were used alternately because speculum tarnished.  The mirror not in use would have to be re-polished and swapped in from time to time.  It was the largest telescope until the 100 inch at Mt. Wilson was put in service in 1917.

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

Addendum

Leviathan of Parsonstown

The 72 inch Leviathan of Parsonstown. source: http://www.klima-luft.de/steinicke/ngcic/persons/rosse3.htm