Tuesday, April 13, 2021

The Pencil Nebula Supernova Shock Wave


This supernova shock wave plows through interstellar space at over 500,000 kilometers per hour. Near the middle and moving up in this sharply detailed color composite, thin, bright, braided filaments are actually long ripples in a cosmic sheet of glowing gas seen almost edge-on. Cataloged as NGC 2736, its elongated appearance suggests its popular name, the Pencil Nebula. The Pencil Nebula is about 5 light-years long and 800 light-years away, but represents only a small part of the Vela supernova remnant. The Vela remnant itself is around 100 light-years in diameter, the expanding debris cloud of a star that was seen to explode about 11,000 years ago. Initially, the shock wave was moving at millions of kilometers per hour but has slowed considerably, sweeping up surrounding interstellar material. In the featured narrow-band, wide field image, red and blue colors track, primarily, the characteristic glows of ionized hydrogen and oxygen atoms, respectively. via NASA https://ift.tt/3mOIgrl

Monday, April 12, 2021

Confirmed Muon Wobble Remains Unexplained


How fast do elementary particles wobble? A surprising answer to this seemingly inconsequential question came out of Brookhaven National Laboratory in New York, USA in 2001, and indicated that the Standard Model of Particle Physics, adopted widely in physics, is incomplete. Specifically, the muon, a particle with similarities to a heavy electron, has had its relatively large wobble under scrutiny in a series of experiments known as g-2 (gee-minus-two). The Brookhaven result galvanized other experimental groups around the world to confirm it, and pressured theorists to better understand it. Reporting in last week, the most sensitive muon wobble experiment yet, conducted at Fermi National Accelerator Laboratory (Fermilab) in Illinois and pictured here, agreed with the Brookhaven result. The unexpected wobble rate may indicate that an ever-present sea of virtual particles includes types not currently known. Alternatively, it may indicate that flaws exist in difficult theoretical prediction calculations. Future runs at Fermilab's g-2 experiment will further increase precision and, possibly, the statistical difference between the universe we measure and the universe we understand. via NASA https://ift.tt/2OH3k6u


Dear High School Students!

You are invited to participate in the 5th Canadian Astronomical Olympiad!

Check the Problems:

1.     Satellite. Phobos has a radius of 11 km while Mars has a radius of 3390 km. Phobos has a circular orbit around Mars which is inclined at 0° to Mars’s equator. The period of Phobos is 7h 40m, while the time it takes for Mars to complete a full rotation around its axis is 24h 37m.

a)     How many times in a Martian day does Phobos rise above the horizon?

b)    Where on the horizon does Phobos rise?

c)     Suppose Mars was inhabited by Martians. Would it be practical for them to create a calendar using Phobos analogous to the lunar calendars we have on earth? There is no single correct answer, but please justify your opinion with three reasons backed up with calculations.

2.     Seasons. A common misconception is that summer and winter are caused by the changing distance between Earth and the Sun. In reality, however, the seasons are caused by Earth’s tilt. For an observer at a latitude of 55°, find the ratio of the solar irradiance at noon of summer solstice to the irradiance at noon of winter solstice due to Earth’s tilt (without considering the changing distance). Find the ratio of the irradiances due to Earth’s changing distance from the sun (without considering Earth’s tilt). Compare the two ratios. What can you conclude?

3.     Polar night. A city has a latitude of 68° 58’. Find the length of the polar night in this city.

4.     Galaxy. Galaxy M96 in Leo has an angular size of 11’ by 8’ and an apparent magnitude of 10m. The wavelength of light emitted in the H and K bands is shifted by 10.3 Å. Given that the wavelengths of ionized calcium are 3968 Å (H) and 3934 Å (K), find the galaxy’s
a) radial velocity,
b) distance to Earth,
c) linear dimensions,
d) absolute magnitude, and
e) luminosity.
5.     Telescope. The photo below shows a picture of the moon taken at the prime focus of a telescope with a CCD chip with dimensions 22.2 by 14.8 mm. The ratio of the sides of the photo is the same as the ratio of the sides of the CCD chip. Find the focal length of the objective lens of the telescope.

6. Beginner Astronomer. An amateur astronomer (φ = +45°) is observing a galaxy in upper culmination at solar midnight on June 21st (summer solstice). They leave for a late-night snack but end up watching 3 hours of TV instead. When they come back 3 hours later, they look at the galaxy again without repositioning their telescope and of course cannot find it. Not knowing that they should reposition their telescope, they think, “Since Earth moves around the Sun and rotates around its axis, is it possible that an increased distance to the galaxy caused it to become too dim to see?”

Prove this astronomer wrong by calculating the change in apparent magnitude of the galaxy during the time they were watching TV. Also calculate the actual apparent magnitude and find the ratio of the two values. Assume Earth’s orbit is circular and the galaxy is stationary relative to the Sun. You may use the following data about the galaxy:

Distance to the Sun (d) = 810 kpc

Surface brightness (μ) = 23.65 mag/arcsec2

Radius (r) = 12 kpc

 

You think you can solve them? If so, send your answers to info@astroclub.ca  by May 17, 2021. You might be one of the lucky winners who will be selected to represent Canada at International Olympiad on Astronomy and Astrophysics 2021!

 


Sunday, April 11, 2021

Alnitak and the Flame Nebula


What lights up the Flame Nebula? Fifteen hundred light years away towards the constellation of Orion lies a nebula which, from its glow and dark dust lanes, appears, on the left, like a billowing fire. But fire, the rapid acquisition of oxygen, is not what makes this Flame glow. Rather the bright star Alnitak, the easternmost star in the Belt of Orion visible on the far left, shines energetic light into the Flame that knocks electrons away from the great clouds of hydrogen gas that reside there. Much of the glow results when the electrons and ionized hydrogen recombine. The featured picture of the Flame Nebula (NGC 2024) was taken across three visible color bands with detail added by a long duration exposure taken in light emitted only by hydrogen. The Flame Nebula is part of the Orion Molecular Cloud Complex, a star-forming region that includes the famous Horsehead Nebula. via NASA https://ift.tt/3uOFGoh

Saturday, April 10, 2021

When Black Holes Collide


What happens when two black holes collide? This extreme scenario occurs in the centers of many merging galaxies and multiple star systems. The featured video shows a computer animation of the final stages of such a merger, while highlighting the gravitational lensing effects that would appear on a background starfield. The black regions indicate the event horizons of the dynamic duo, while a surrounding ring of shifting background stars indicates the position of their combined Einstein ring. All background stars not only have images visible outside of this Einstein ring, but also have one or more companion images visible on the inside. Eventually the two black holes coalesce. The end stages of such a merger is now known to produce a strong blast of gravitational radiation, providing a new way to see our universe. via NASA https://ift.tt/3fZiWgS

Friday, April 9, 2021

Zodiacal Night


An intense band of zodiacal light is captured in this serene mountain and night skyscape from April 7. The panoramic view was recorded after three hours of hiking from a vantage looking west after sunset across the Pyrenees in southern France. At 2838 meters altitude, Mont Valier is the tallest peak near center. In the sky above, the familiar stars of Orion and the northern winter Milky Way are approaching the rugged western horizon. At the shoulder of Orion, Betelgeuse is one of three bright yellowish celestial beacons. It forms a triangle with fellow red giant star Aldebaran located below Betelgeuse and to the right, and the red planet Mars. Mars shines just under the band of the Milky Way, still immersed in the bright zodiacal light. via NASA https://ift.tt/2RpeSMT

Thursday, April 8, 2021

Messier 106


Close to the Great Bear (Ursa Major) and surrounded by the stars of the Hunting Dogs (Canes Venatici), this celestial wonder was discovered in 1781 by the metric French astronomer Pierre Mechain. Later, it was added to the catalog of his friend and colleague Charles Messier as M106. Modern deep telescopic views reveal it to be an island universe - a spiral galaxy around 30 thousand light-years across located only about 21 million light-years beyond the stars of the Milky Way. Along with a bright central core, this stunning galaxy portrait, a composite of image data from amateur and professional telescopes, highlights youthful blue star clusters and reddish stellar nurseries tracing the galaxy's spiral arms. It also shows off remarkable reddish jets of glowing hydrogen gas. In addition to small companion galaxy NGC 4248 at bottom right, background galaxies can be found scattered throughout the frame. M106, also known as NGC 4258, is a nearby example of the Seyfert class of active galaxies, seen across the spectrum from radio to X-rays. Active galaxies are powered by matter falling into a massive central black hole. via NASA https://ift.tt/3d3UrNM