3 years ago
A GREEN COMET APPROACHES EARTH: Comet 21P/Giacobini-Zinner is approaching Earth. On Sept. 10th, it will be 0.39 AU (58 million km) from our planet and almost bright enough to see with the naked eye. Already it is an easy target for backyard telescopes. Last night, Michael Jäger of Weißenkirchen, Austria, caught the 7.7th magnitude comet passing through star cluster Tombaugh 5 in the constellation Camelopardalis:
This comet is relatively small--its nucleus is barely more than a mile in diameter--but it is bright and active, and a frequent visitor to the inner solar system as it orbits the sun once every 6.6 years. On Sept. 10th, 21P/Giacobini-Zinner will not only be near Earth, but also at perihelion, its closest approach to the sun. Solar heating will make it shine like a star of 6th to 7th magnitude, just below the threshold of naked-eye visibility and well within range of common binoculars. Detailed sky maps will help you find it.
21P/Giacobini-Zinner is the parent of the annual Draconid meteor shower, a bursty display that typically peaks on Oct. 8th. Will the shower will be extra-good this year? Maybe. Draconid outbursts do tend to occur in years near the comet's close approach to the sun. However, not every close approach brings a meteor shower. Forecasters say there are no known Draconid debris streams squarely crossing Earth's path this year, so we will have to wait and see.
Click to view an interactive 3D orbit of 21P/Giacobini-Zinner as it passes by our planet in 2018: ssd.jpl.nasa.gov/sbdb.cgi?sstr=21P;cad=1;old=0;orb=1;cov=0;log=0#orb
Note: "AU" means "astronomical unit." 1 AU is the distance between Earth and the sun. The distance to Comet 21P/Giacobini-Zinner on Sept. 10th will be ~0.39 AU or 58 million km. On the scale of things in the solar system, the comet will be close to Earth, but not scary-close. ...
TONIGHT! THE GEMINID METEOR SHOWER: On Dec. 13th and 14th, Earth will pass through a stream of gravelly debris from rock comet 3200 Phaethon, source of the annual Geminid meteor shower. Sky watchers far from city lights could see dozens of meteors per hour. The best time to look, no matter where you live, is during the dark hours before dawn on Thursday the 14th when the constellation Gemini is high overhead. ...
This LRGB image of NGC 7635 was taken over successive nights at AMO while fighting clouds and terrible seeing between Oct 24th and 27th. Also known as the Bubble Nebula, it lies very close to the open cluster Messier 52. The visible bubble is created by the stellar wind from the massive and very hot 8.7 magnitude central star knows as SAO 20575. The expansion of this very large H II region emission nebula is contained by a giant molecular cloud which is also excited by the central star causing it to glow. The Bubble Nebula was discovered by William Herschel in 1787 and is faintly visible using averted vision in an 8" to 10" telescope and clearly visible in one larger than 14" especially when using an H-alpha narrowband filter which really helps enhance the contrast. ...
Your pictures of what is placed in the heavens inspire and the knowledge you share always enhances the visual experience. This Nebula is so beautiful. What a sight to see.
Where do I find a translation for this language? Ha ha! It’s beautiful and amazing!
Where are the elements created....?APOD: Where Your Elements Came From (2017 Oct 24)
Image Credit & License: Wikipedia: Cmglee;
Data: Jennifer Johnson (OSU)
Explanation: The hydrogen in your body, present in every molecule of water, came from the Big Bang. There are no other appreciable sources of hydrogen in the universe. The carbon in your body was made by nuclear fusion in the interior of stars, as was the oxygen. Much of the iron in your body was made during supernovas of stars that occurred long ago and far away. The gold in your jewelry was likely made from neutron stars during collisions that may have been visible as short-duration gamma-ray bursts or gravitational wave events. Elements like phosphorus and copper are present in our bodies in only small amounts but are essential to the functioning of all known life. The featured periodic table is color coded to indicate humanity's best guess as to the nuclear origin of all known elements. The sites of nuclear creation of some elements, such as copper, are not really well known and are continuing topics of observational and computational research.
Starship Asterisk* • APOD Discussion Page
POLAR MAGNETIC STORMS: Minor G1-class geomagnetic storms are underway today, Oct. 25th, in response to a stream of solar wind buffeting our planet's magnetic field. So far the action is restricted to polar regions. However, NOAA forecasters say there is a chance the storm will intensify to G2-class as Earth moves deeper into the stream. If so, auroras could descend into northern-tier US states along a line from Maine to Washington.
Photo credit: Tom Arne Moldenaes on October 24, 2017 @ Tromso, Norway ...
This image taken the night of Oct 23rd, 2017 is an LRGB shot of NGC 7662, also known as the Blue Snowball or the Snowball Nebula. It is a planetary nebula located in the constellation Andromeda at distance of between 1800 and 5700 light years (astronomers are not really sure.) Planetary nebulae are emission nebulae consisting of an expanding, glowing shell of ionized gas ejected from old red giant stars as they die. At magnitude 8.6, this object is very easy to see in most amateur telescopes with the disk resolvable in a 6" telescope at 50x magnification. To find it, center your telescope on the 6th-magnitude star 13 Andromedae and you should have the nebula in the eyepiece field, 1/2 degree southwest of the star. ...
In the constellation Cepheus, 1,300 light years away lies the Iris Nebula - LBN 487 with a star cluster (NGC 7023) embedded in it. Also know as Caldwell 4, the nebula is illuminated by a magnitude +7 star, SAO 19158. This LRGB image was taken using the AMO 0.5m folded newtonian telescope with a Fingerlakes Dream Machine camera using the same type of TK1024 CCD sensor that was used for the original HST wide field planetary camera. ...
For most astronomers, the Moon is a pariah that obscures the wonderful deep sky treasures with its glaringly bright reflection of sunlight. Despite this, every time I get a visual telescope out, Jackie wants to see the Moon! This image of the Moon is for her. Its a mosaic of multiple DSLR images taken with a 130mm Astro-Physics refractor. ...