* Astronomy

Blobrana · L

RE: October 2015

Blobrana · L

Meteor Showers

There are many minor meteor showers this month...
Orionids produce rates of 5-15/hour with occasional surges in activity that may reach 25 or even 50/hour. The shower's radiant near Betelgeuse is best-placed just before morning twilight begins. Its radiant is R.A. 6hr 20m Dec +16 degrees, which is close to Xi Orionis. They're from Halley's Comet. October 15-29 2013 Maximum Oct. 21.
Draconids have produced two major storms in 1933 and 1946, and several other significant outbursts. Draconids are very slow meteors. The parent body of the meteors is Comet Giacobini-Zinner. October 6-10, Maximum Oct. 9/10
Epsilon Geminids On the 18th, the radiant will be at RA 6h 48m, Dec +27, several degrees north of the star epsilon Gemini, (Mebsuta). These are fast meteors, at about 70 km per second. These meteors might be associated with either Comet Ikeya, C/1964 N1, or Comet Nishikawa-Takamizawa-Tago, C/1987 B1. ZHR rates for this shower are about 2 meteors per hour at maximum. October 10-27 Maximum Oct. 18/19
The Sextanids are active September 9 through October 9. Though, this one is more of a radio/radar shower
The northern Taurids and southern Taurids start to become active about October 1st, but do not reach maximums until early November. Both have fairly slow meteors, with the northern Taurids velocity at 29 km per second, and the southern at 27 km per second. At maximum in November, both showers will peak at about ZHR rates of 5 meteors per hour. These meteors are part of the Taurid stream which in turn has been associated with Comet Encke.

Shower	Activity Period	Maximum	Radiant		Velocity	ZHR
		Date	R.A.	Dec.	km/s
Orionids		Oct 21	6h20m	16°		25
Sextantids	Sept 24-Oct 9	Oct 1	10.5h	-8.7°	29.8km/s	9
Eta Cetids	Sept 20-Nov 2	Oct. 1-5	38°	3°
October Cygnids	Sept 22-Oct 11	Oct. 4-9
Arietids	Sept-Oct	Oct 8/9
Delta Aurigids	from Sept 22-Oct	Oct. 6-15			64km/s	23
Draconids	October 6-10	Oct. 9/10	17.8h	78.1°	28.7km/s	35
Epsilon Geminids	October 10-27	Oct. 18/19	6h48m	27°	66km/s	2
Leo Minorids
Northern Piscids						3
Northern Taurids	Oct 1 - Nov	November	3.2h	17.5°	29km/s	5
Southern Taurids	Oct 1 - Nov	November			27km/s	5

Blobrana · L

Highlights

Halloween, the word itself, is a contracted corruption of All Hallows Eve. It actually has its origins in the Celtic New Year. The holiday was called Samhain (Sah-ween). The date marked the beginning of winter. The Celts believed that at the time of Samhain, more so than any other time of the year, the ghosts of the dead were able to mingle with the living, because at Samhain the souls of those who had died during the year travelled into the other world. People gathered to sacrifice animals, fruits, and vegetables. They also lit bonfires in honour of the dead, to aid them on their journey. Here are a few deepsky objects to look out for:

In Aquila , NGC 6781 "The Ghost of the Moon Nebula"
In Cetus, NGC 246 called "The Skull Nebula".
In Bootes (abbreviated "BOO"), you may find The Spider Galaxy, NGC5829 .

The Constellation of Ophiuchus
Next to Hercules and standing on Scorpius, you will find the large constellation of Ophiuchus. The brightest star of Ophiuchus is Rasalhague, which means Head of the Snake Charmer and is only at magnitude 2. You can see this constellation, which looks a bit like a misshapen triangle under less than ideal conditions.
Ophiuchus, the Serpent Bearer, was formerly known as Serpentarius. In mythology, it is associated with the healer Aesculapius, who became so skilled that he was able to bring the dead back to life. To avoid depopulation of the underworld, Jupiter disposed of Aesculapius with a thunderbolt, but relented sufficiently to place him in the sky.
Ophiuchus contains seven Messier objects M9, M10, M12, M14, M19, M62 and M107 - which are all globular star clusters. At right ascension 18 hours 28 m, declination 6 degrees 30 m (the upper left hand corner of the constellation) there is an open star cluster that is labelled NGC 6633 (from a catalogue compiled in 1888, called the "New General Catalogue"). An open cluster consists of a large number of stars, although not as dense as a globular cluster.
M9 (NGC 6333) is the smallest of this group, unresolved except in large instruments. The cluster is found 3.5° SE of eta Ophiuchi. It is considered to be about 26,000 light years away. In the same field are two more globular clusters: NGC 6342 (1° SE) and NGC 6356 (1° NE).
M10 (NGC 6254) and M12 (NGC 6218) are nearly identical globular clusters: like tiny explosions of stars with dense cores. M12 is eight degrees north of zeta Ophiuchi and two degrees east. M10 is 2.5 degrees SE of M12, with 30 Ophiuchi in the same field.
M14 (NGC 6402) needs a 20-cm telescope to resolve; it's more condensed than the preceding two and slightly fainter.
M19 (NGC 6273) is another very dense cluster, usually described as "oblate", or egg-shaped. It is about 25000 light years away. M19 is seven degrees due east of Antares in Scorpius, or two and a half degrees west of the bright double 36
Ophiuchi (and very slightly north, less than a degree).
M62 (NGC 6266) is six degrees SW of theta Oph (and four degrees south of M19); this is another non-circular globular cluster, a little brighter than M19. (Note: Burnham includes this Messier in Scorpius; nearly all other authorities put it in Ophiuchus.)
M107 (NGC 6171) is the faintest of the bunch and quite small. This is one of those "Messiers" that were added to the original list. It's three degrees SSW of zeta Ophiuchi.
B78, the "Pipe Nebula", is a naked eye dark nebula 2° southeast of theta Ophiuchi, in a very rich area of the Milky Way.

Barnard's Star is the most rapidly moving star relative to the solar system, and the second closest star to us, at a distance of only 5.91 light years. This is a red dwarf, with a visual magnitude of only 9.5, and consequently not easily found. The star is three degrees due east of beta Ophiuchus. A slight oscillation in both the right ascension and declination of Barnard's Star has led observers to suggest the possibility that one or more planets orbit the star.
In the upper-left, less than 2 degrees north- east of Beta, is IC-4665, a beautiful open cluster that can be seen very well with ordinary binoculars.

The Pleiades
New to the sky in late evening you'll see the wonderful gem of an open cluster rising in the East. As Tennyson said "The Pleiads , rising thro' the mellow shade, Glitter like a swarm of fireflies Tangled in a silver braid...".
Nearly every culture mentions the Pleiades in some respect. Chinese writings appear to mention it from 2357 BC. American Indian folklore of the Kiowa talks of the "Seven Maidens" who where protected from giant bears by their placement in the skies. To the Japanese, they are called Subaru.

Blobrana · L

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