Friday 23 December 2016

Astrognome Scrapbook Rhea


The second largest moon of Saturn Rhea was discovered on December 23rd 1672 by Giovanni Cassini.  In Greek mythology Rhea was the ‘mother of gods’.

It is a rocky body with a radius of around 760 km, Rhea takes about 4.5 days to orbit Saturn once.

Cassini would also discover the moons Dione, Iapetus and Tethys which also orbit Saturn. 

The space craft Cassini which has been orbiting Saturn is named after the famous astronomer.

Tuesday 20 December 2016

The Astronomy Show 21.12.16

The Astronomy Show 21st December 

It is the star that everyone talks about at this time of year, but what was the Star of Bethlehem? Today I will take an astronomer’s view of just what the star, if it was a star might have been.

 The top 20 bright stars continue with Spica, the Messier Marathon is M14 in Ophiuchus and the A-Z of constellations continues with Capricornus.

This plus what's in the night sky this week, the latest astronomy news, the astronomy scrapbook for this week and the astronomy society meetings in the north.

The Astronomy Show 3.00 pm- 5.00 pm with Martin Lunn on Drystone Radio 103.5 FM, on line at or listen on the podcast.

Astrognome Scrapbook Walter Adams

Walter S Adams

Walter Adams was born in Syria on December 20th 1876, Adams was the son of American missionaries. After receiving his bachelor's degree at Dartmouth College, he accompanied his astronomy professor, Edwin B. Frost, to Yerkes Observatory. After two years there he worked with Yerkes director, George Ellery Hale, to help establish the Mt. Wilson Solar Observatory.

His spectroscopic studies of the sun, done with Hale and others, led to the discovery that the sunspots are regions of lower temperatures and stronger magnetic fields than their surroundings.

He shared with Theodore Dunham, Jr. in the discoveries of carbon dioxide in the atmosphere of Venus. Adams identified Sirius B as the first white dwarf star known, and his measurement of its gravitational redshift was taken as confirming evidence for the general theory of relativity.

Walter Adams died on May 11th 1956.

Monday 19 December 2016

Astrognome Scrapbook Skylab

Skylab Solar Flare Picture

Skylab was a space station launched and operated by NASA and was the United States' first space station. Skylab orbited Earth from 1973 to 1979, and included a workshop, a solar observatory, and other systems. It was launched unmanned by a modified Saturn V rocket.

 Three manned missions to the station, conducted between 1973 and 1974 using the Apollo Command/Service Module (CSM) atop the smaller Saturn IB, each delivered a three-astronaut crew.

On December 19th 1973 the now famous picture of a giant solar prominence loop on the Sun was taken.

Friday 16 December 2016

Astrognome Scrapbook Sunspots 511 AD

Sunspots 511 AD

On the 16th December 511 AD two large sunspots were seen on the Sun. 
They were seen by Chinese astronomers and were described as looking like two black vapours as large as peaches.

Thursday 15 December 2016

Astrognome Scrapbook Janus


On December 15th 1966 the small moon Janus was discovered orbiting Saturn. The discovery was made by the French astronomer Audouin Charles Dollfus. Janus is named after the god of gates and doorways.

It is a potato shaped moon with dimensions of 122 x 119 x 93 miles (196 x 192 x 150 km).

Janus orbits 94,000 miles (151,000 km) away from Saturn, taking 17 hours to complete one orbit of Saturn.

 It shares the same orbit as the small moon Epimetheus and are separated only by about  31 miles (50 Km).

Tuesday 13 December 2016

The Astronomy Show 14.12.16

Astronomy  Show 14.12.16

The Astronomy Show this week will be looking at the top 10 meteor craters on the Earth and could another asteroid have our name on it?

The top 20 bright stars continues with Antares, the Messier Marathon is M13 in Hercules and the A-z of constellations continues with Canis Minor.

This plus what's in the night sky this week, the latest astronomy news, the astronomy scrapbook for this week and the astronomy society meetings in the north.

The Astronomy Show 3.00 pm- 5.00 pm with Martin Lunn on Drystone Radio 103.5 FM, on line at or listen on the podcast.

Astrognome Scrapbook DQ Hercules

DQ Hercules

On the night of December 13th 1934 the amateur British astronomer J P M Prentice discovered a nova in Hercules near the border with Vega. On the night of discovery it was at mag 3.4 and during the rest of December increased in brightness reaching greatest brightness on December 22 1934 at mag 1.3. Previous to going nova the star had been of the 15th magnitude.

DQ Her is near the top left hand corner of the map

A slow fade followed, with the nova losing 3 magnitudes in 94 days followed by a more rapid decline of 8 magnitudes in just one month. DQ Hercules then brightened once more to reach a second fainter maximum of 6.5, which was then followed by a long slow decline to minimum. 
 A similar pattern can be seen in the light curve for Nova T Auriga 1891 and Nova Cassiopeia 1993 (V705 Cassiopeia).

Monday 12 December 2016

Astrognome Scrapbook Henrietta Leavitt

Henrietta Swan Leavitt 1868-1921

One of the great pioneers of stellar physics Henrietta Swan Leavitt died on December 12th, 1921.
She was born on July 4th, 1868 in Lancaster, Massachusetts. As a young child, her family moved to Cleveland, Ohio. Leavitt attended Oberlin College and in 1892 graduated from the Society for the Collegiate Instruction for Women, now known as Radcliffe College. She then traveled in America and in Europe during which time she lost her hearing. Three years after graduation, she became a volunteer research assistant at Harvard College Observatory. Seven years later, in 1902, Pickering hired her on the permanent staff.

Leavitt’s interest in astronomy began during her senior year in college when she took an astronomy class. She furthered her studies in astronomy with graduate work. As an assistant at Harvard College Observatory, though she had the ability, she was given little theoretical work. Pickering did not like his female staff to pursue such endeavors. Instead, she was given the position of chief of the photographic photometry department and was responsible for the care of telescopes.
Leavitt also was required to perform research from the observatory’s photographic plates collection. Using the plates, she was to determine a star’s magnitude. There was no standard for ascertaining magnitudes at the time. Leavitt devised a system, using “the north polar sequence” as a gage of brightness for stars during her investigations. This was quickly recognized by the scientific community as an important standard and in 1913, was adopted by the International Committee on Photographic Magnitudes.

Another area of research that Leavitt pursued was on variable stars and in 1908 she made her most important discovery. By studying Cepheid variables in the Small Magellanic Cloud, which are all about the same distance from Earth, Leavitt determined the absolute magnitudes of stars. Her study led to the period-luminosity relationship of these variables, which in turn led to the ability to determine distances of stars from a mere one hundred light years to ten million light years. Ejnar Hertzsprung used her discovery to plot the distance of stars; Harlow Shapley used it to measure the size of the Milky Way; and Edwin Hubble used her work to ascertain the age of the Universe.

Interestingly Delta Cephei the prototype Cepheid variable star was discovered by John Goodricke in York in 1784. He was also deaf!

Leavitt died on December 12th, 1921 from cancer. During her lifetime, she discovered over 1,200 variable stars, half the number of all such objects known at the time of her death. She was also a member of many organizations and a proponent for women in astronomy. She made monumental contributions to the advancement of astronomy and our understanding of our place in the Universe. There is no way of knowing what other contributions she would have made had she not died so young.

The asteroid 5383 Leavitt and the lunar crater Leavitt are named in her honour.

Friday 9 December 2016

Astrognome Scrapbook Adrian Metius

Adrian Metius 9th Dec 1571- 26th Sept 1635

Adrian Metius was born at Alkmaar in Holland; he was a pupil of Tycho Brahe, he later became an astronomer, mathematician and military engineer. 

He made considerable improvements to the astronomical instruments of his time. In 1624 he wrote ‘De usu Globi Coelestis’ containing a description of a 7 feet iron radius mounted on a universal bearingwith sights at both ends. He died at Frankfurt.  

Thursday 8 December 2016

Astrognome Scrapbook Al Sufi

Al Sufi

One of the great arab astronomers, Al-Rahman or Al Sufi was born on December 8th 903 AD at Ravvy, Persia observed from Shiraz, Basra and Baghdad; he wrote a book in 964 called The Book of Fixed Stars with descriptions of the 48 constellations and also giving information on individual stars.

In addition to the stars he also mentions a little cloud, which is M31 the Andromeda Galaxy and refers to one of the Magellanic clouds under the name of the ‘white ox’.

Al Sufi died on May 25th 986. 

Wednesday 7 December 2016

Astrognome Scrapbook SN 185 AD

SN 185 AD

Supernova (SN) are pretty rare, however one did appear in our galaxy and was first sighted on December 7th 185. The SN appeared between the constellations of Centaurus and Circinus.

SN 185 was close to alpha Centaurus right on the border with Circinus 

The Chinese have astronomical records going back several thousand years and are usually reliable. The Chinese astronomers described a ‘Guest Star’ which was visible for 8 months. It was reported as follows:- In the 2nd year of the epoch Zhongping on the day Kwei Hae [December 7], a strange star appeared in the middle of Nan Mun [asterism containing Alpha Centauri], It was like a large bamboo mat. It displayed the five colours, both pleasing and otherwise.

The gaseous shell RCW 86 is probably the supernova remnant of this event and is about 9,000 light-years away. This is the earliest record we have of a star destroying itself in a supernova explosion.

RCW 86

Using information from the Chandra satellite astronomers believe that the supernova was similar to the one that Tycho saw in 1572 and became about as bright at magnitude -4.0.

Monday 5 December 2016

Astrognome Scrapbook Jupiter in 337 BCE

Jupiter 337 BCE

On December 5th 337 BCE Aristotle saw Jupiter pass in front of or occult a star in Gemini, possibly the star we know today as FL 1 Gemini.

Friday 2 December 2016

Astrognome Scrapbook Solar Max Missions Ends

Solar Max Mission Ends

The Solar Maximum Mission ended on December 2, 1989, launched on February 14 1980 the Solar Max mission was designed to study solar flares.

Due to problems with the on board systems the probe had to be repaired and it became the first probe to be repaired while in orbit around the Earth when the shuttle Challenger in 1984.

The major discovery of the mission was that the Sun was actually brighter when the Sun is at sun spot maximum.  This is because sunspots are surrounded by bright features called faculae, which more than cancel the darkening effect of the sunspot.

Over a period of time the drag from the Earth`s atmosphere caused the spacecraft to re-enter the Earth's atmosphere. Re-entry occurred at 10:26 UT on 2 December 1989 over the Indian Ocean.

Thursday 1 December 2016

Astrognome Scrapbook Nicholas Claude Fabri de Peiresc

Nicholas Claude Fabri de Peiresc

He was born on December 1st 1580 in France. In November 1610 he obtained a telescope from his brother in France. He made observations of the satellites of Jupiter from 1610-1612. He observed sunspots and the Orion Nebula.

He built an observatory on the top of his house, and he obtained a telescope from Galileo in 1635. He then observed from many locations including Cairo, Aleppo and elsewhere in Europe.

He showed that the Mediterranean Sea was 600 miles shorter than was accepted at the time.

 He died on June 24th 1637