At 7:30 PM, 11 January 2019, at the Sunshine Coast Art Centre, 5714 Medusa St., Sechelt, the Sunshine Coast Centre of the RASC presents Paul Gray, the editor of the RASC Calendar, who will be doing a presentation on Dark Nebulae. A dark nebula or absorption nebula is an interstellar cloud so dense that it obscures the light from objects behind it, such as background stars and emission or reflection nebulae. Interstellar dust grains, coasted with frozen carbon monoxide and nitrogen, in in the coldest, densest parts of larger clouds effectively block the passage of light at visible wavelengths. These clouds are the spawning grounds of stars and planets, and understanding their development is essential to understanding star formation.
The largest dark nebulae, like the Coalsack Nebula and the Great Rift, are visible to the naked eye, appearing as dark patches against the brighter background of the Milky Way.
Admission is free: donations gratefully accepted at the door.
Last night (Saturday, 1 December), We conducted a training session at the observatory and Shannon McLaughlin completed her training as Qualified Operator. Ed Hanlon came later and went through some of the training, but we were losing the sky by that time, so he’ll come back and complete the QO course later.
If you’re interested in learning how to use the observatory telescope, please contact me. We’ll take you through the procedure of opening/closing the observatory, starting up and parking the telescope, navigating the night skies with the telescope, and recovering from telescope failures to get back into action quickly.
Charles Ennis, Past President
At last night’s public viewing session at our observatory we broke two records. One concerned yearly attendance, which stood at 311 just two days ago. Last year’s total attendance was only 159, so we knew to double that we needed just 7 more people to attend this year. Attendance last night was 29, which is the highest attendance ever recorded at a public session. So we easily pushed past doubling last year’s attendance to a new record of 340. And the year isn’t done yet! We had people of all ages at the observatory last night. One little girl told us her favorite planet was Saturn, and was ecstatic when she saw it for the first time in the eyepiece. Several members worked on their observing certificates. James MacWilliam showed up with his guitar and entertained us for hours. A thoroughly entertaining evening.
Every year, between November 6-30, Earth sweeps through a stream of debris left behind by Comet Tempel-Tuttle. The number of meteors increases as the Earth moves deeper into the stream and reaches a peak on the night of the 17th. As the radiant, the point in the sky that the meteors can be traced back to, is inside the constellation Leo, this is called the Leonid meteor shower.
Most meteoroid streams contain only minuscule bits of dust and ice. However, the stream for the Leonids also contains many gravel-sized bits. This produces some very bright meteors in the night sky.
The Leonid meteor shower only produces around 15 meteors per hour, on average. Occasionally, usually shortly after Comet Tempel-Tuttle makes a pass around the Sun, the Leonids can deliver a meteor storm, with hundreds of meteors streaking through the sky every hour. According to experts, such a storm is not expected again until 2033 or 2034.
Leo is rising around 11 pm on the 17th and is fully visible by 2 am on the 17th-18th. The peak of the shower is actually 5 AM on the 17th, so the predawn hours on Saturday are the best viewing time. The Moon is two days past First Quarter on the 17th this year, so there will be some competing light in the sky, which will wash out the faintest meteors. However it will certainly be worthwhile to check the peak out on the 17th. It will definitely be worth it to get out to see the brightest of them, though! Bruce Fryer, Scott Harlow, and I were at the observatory last night and saw a few early arrivals which were quite impressive.
There are two Taurid meteor showers: Northern and Southern. This is because they originate from the debris left behind by two different objects.
- Northern: Asteroid 2004 TG10; and
- Southern: Comet Encke
These two showers overlap into one shower, with two different peaks. Observers note that the meteors in these showers tend to be slower, taking their time to transit the sky, producing some extremely bright bolides. At peak, the Taurids only produce about 5 – 10 meteors per hour. This year the Moon is near new (New Moon on the 7th, First Quarter on the 15th), improving the viewing conditions.
The Crescent Nebula (NGC 6888) is a cosmic bubble about 25 light-years across in the constellation Cygnus, blown by winds from its central, bright, massive star. The nebula’s central star is classified as a Wolf-Rayet star (WR 136). The star is shedding its outer envelope in a strong stellar wind, ejecting the equivalent of the Sun’s mass every 10,000 years. The nebula is 5000 light years from us.
I captured the image last weekend with a Megrez 120mm, Canon 60Da camera, unfortunately exposure was limited to 120 minutes in all, the image was processed in PixInsight. Mike
Due to a shortage of instructors we have had to cancel the public night at the SCAC Observatory for October 13th.
Please accept our apologies for this.