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(meteorobs) Radio, Review Icom R-75
I just purcased a ICOM R-75 just for a good Shortwave receiver but to my
surprise it goes all the way to 60 MHZ. Well I said to myself, " Self, this
may work for meteor scatter on 55mhz channel 2 TV". And gess what? I works
great. I took it to the mountains this weekend near lake tahoe and was in a
remote area and was able to hear echos with just a short piece wire stuck in
the back. I am impressed and thats without the optional DSP in it. More
testing to follow.
Norm
----- Original Message -----
From: "Robert Lunsford" <lunro.imo.usa@home.com>
To: "Meteor List" <meteorobs@atmob.org>
Sent: Friday, July 13, 2001 2:29 PM
Subject: (meteorobs) Meteor Activity Outlook for July 13-19, 2001
> The moon reaches its last quarter phase on Friday July 13th. This means
> that the evening skies are free from moonlight while the morning skies
> suffer some limited interference. This interference becomes less of
> a factor as the moon approaches its new phase on July 20. The estimated
> total hourly rates for evening observers this week should be near 2 for
> those in Northern Hemisphere and 3 for Southern Hemisphere observers.
> For morning observers the estimated total hourly rates should be near 10
> for the Northern Hemisphere and 13 for those located in the Southern
> Hemisphere with some lunar interference. These rates assume that you are
> watching from rural areas away from all sources of light pollution
> except for the moon. The actual rates will also depend on factors such
> as personal light and motion perception, local weather conditions,
> alertness and experience in watching for meteor activity. The positions
> listed below are exact for Saturday night/Sunday morning July 14/15. The
> positions do not change greatly day to day so these positions may be
> used during this entire period.
>
> The July Phoenicids last only a week centered on its July 12 maximum.
> The radiant lies at 02:20 (035) -47. This area of the sky is located in
> southern Eridanus 8 degrees southwest of the 3rd magnitude star Acamar
> (Theta Eridani). The DMS lists this radiant 8 degrees northwest of this
> position in extreme eastern Phoenix. At 47 km/sec. these meteors would
> be a bit faster than your average meteor. Due to the extreme southern
> declination these meteors are not well seen north of 30 degrees N
> latitude. It would be interesting for far southern observers to see
> exactly where this radiant lies as it rises much higher in their sky. It
> is best placed highest in the sky just before the beginning of morning
> twilight.
>
> The Alpha Capricornid radiant is located at 19:36 (294) -14. This area
> of the sky is located in a remote area of northeastern Sagittarius. This
> area also lies in the outer radiant area of the antihelion radiant. Any
> meteor traveling east or west out of this area would be difficult to
> classify. At this time rates of the Alpha Caps and the antihelion
> radiant would be similar. With an entry velocity of 25 km/sec. the Alpha
> Caps are just a bit slower than the antihelion meteors. The Alpha Cap
> radiant is best placed near 0100 local daylight time (0000 local
> standard time) when it lies on the meridian. This radiant is noted for
> its colorful fireballs which will occur more frequently as we approach
> the July 30 maximum.
>
> The Alpha Cygnids are listed as the Psi Cygnids among the radiants of
> the Dutch Meteor Society. No matter what you call them they are often
> overlooked by the many other better known radiants active at this time.
> This radiant was well represented in the studies coordinated by Peter
> Jenniskens between 1980 and 1991. Their studies indicate a ZHR near 3 at
> maximum activity on July 18. The radiant position is 20:12 (303) +46.
> This position is located in central Cygnus 5 degrees west of the bright
> star Deneb (Alpha Cygni). With an entry velocity of 37 kilometers per
> second these meteors are of average speed. The radiant is best placed
> for observing near 0200 LDT or 0100 local standard time when it lies
> nearly overhead for much of the Northern Hemisphere. Due to its high
> northern declination this activity is not well seen from the Southern
> Hemisphere.
>
> The Antihelion radiant is now located at 20:28 (307) -18. This area of
> the sky is located in western Capricornus near the 5th magnitude star
> Rho Capricorni. Any slow to medium speed meteor from western
> Capricornus, northeastern Sagittarius, southeastern Aquila, or
> southwestern Aquarius may be a good candidate for this shower. This area
> of the sky is best placed near 0200 local daylight time (0100 local
> standard time) when it lies on the meridian. At this time expect to see
> perhaps 1 per hour from locations in the Northern Hemisphere and 2
> meteors per hour from the Southern Hemisphere. Unlike most of the
> annual showers the antihelion radiant is produced by debris from unknown
> sources orbiting in a direct motion like the earth. These sources are
> most likely asteroids, which produce stony and metallic debris whose
> density is much greater that produced by comets. This debris collides
> with the earth on the inbound portion of its orbit, before its closest
> approach to the sun. Therefore we best see them just after midnight
> when we are facing the direction from which this activity appears. The
> antihelion radiant is active all year from an area of the sky nearly
> opposite that of the sun. The radiant will travel approximately one
> degree eastward per day and travels through many different
> constellations over the course of a year.
>
> The North Delta Aquarids reach a ZHR (zenith hourly rate) of 1 on July
> 15. The date of maximum activity is not until August 8 so this low rate
> of activity will prevail throughout most of July. The radiant is
> currently located at 21:04 (316) -10. This area of the sky is located
> in southwestern Aquarius 2 degrees northwest of the 4th magnitude star
> Nu Aquarii. Like the Alpha Caps this radiant lies within the boundaries
> of the antihelion radiant area. The NDA's are noticeably swifter than
> the antihelion meteors at 42 km/sec. verses 30 km/sec. This radiant is
> best placed between 0200 and 0300 LDT or 0100 to 0200 local standard
> time when it is located highest in the southern sky. Like many of the
> radiants active this time of year the NDA's are better seen from areas
> south of the northern tropics or 30 degrees north latitude.
>
> The South Delta Aquarid radiant provides the strongest shower of July.
> This radiant peaks in strength on July 27 with an average ZHR of 20. At
> this time rates are only 1-2 per hour but this will quickly rise as we
> approach late July. The current radiant position lies at 21:56 (329)
> -19. This area of the sky is located on the Aquarius/Capricornus border
> 4 degrees southeast of the 3rd magnitude star Nashira (Delta
> Capricorni). The radiant lies low in the southeast at dusk and is not
> well seen until it approaches the meridian near 0300 local daylight time
> or 0200 LST. These meteors encounter the earth at 41 km/sec. which is a
> bit faster than average. These meteors are better seen from the Southern
> Hemisphere where the radiant passes overhead. At this time observers in
> high northern will be lucky to seen any activity at all from this
> radiant.
>
> The Pisces Austrinids are also just now coming to life with a ZHR of 1.
> Don't expect to see 1 an hour unless you live near 30 degrees south
> latitude when the radiant passes overhead between 0200 and 0300 LDT. The
> current radiant location is 22:00 (330) -34 which places it in southern
> Pisces Austrinus 1 degree southwest of the 4th magnitude star Mu Piscis
> Austrini. These meteors are of average velocity, slower than the
> Aquarids but faster than the Alpha Caps and the antihelion meteors.
>
> The Northern Apex radiant is now located at 01:28 (022) +24. This
> position lies in eastern Pisces 9 degrees west of the 2rd magnitude star
> Hamal (Alpha Arietis). This area of the sky is best placed for viewing
> during the last dark hour before dawn. Since this radiant is diffuse any
> meteors from northern Pisces or western Aries could be a good candidate.
> As seen from the Northern Hemisphere this source should produce at least
> 2 meteors per hour during the last few hours before dawn. Rates seen
> from the Southern Hemisphere should be slightly less at 1 per hour. Like
> the antihelion radiant both apex radiants are active all year long and
> travel approximately one degree eastward per day. Unlike the antihelion
> debris these particles orbit the sun in a retrograde motion opposite
> that of the earth and are most likely produced by unknown comets. They
> strike the earth after their closest approach to the sun. Since they are
> moving in opposite directions these particles strike the earth at
> tremendous velocities often creating bright meteors with persistent
> trains. These particles strike the earth on the morning side of earth
> and are best seen just before morning twilight while the sky is still
> perfectly dark. There are meteors with a zero inclination that radiate
> precisely from the apex point on the ecliptic, exactly 90 degrees west
> of the sun. These meteors are rare though as the earth orbits the sun it
> "sweeps clean" much of the material that shares the same orbit. Much
> more debris is located just north and south of the earth's orbit with
> slightly higher or lower inclinations. This creates the northern and
> southern branches of the apex activity. Meteors from both branches are
> normally included in the sporadic count but should also be noted in some
> manner as to which branch of the apex complex they appear to radiate.
>
> The Southern Apex source lies exactly 30 degrees south of its northern
> counterpart at 01:28 (022) -06. This position lies in central Cetus 3
> degrees northeast of the 4th magnitude star (Theta Ceti). Like the
> northern apex these meteors are best seen toward dawn when the radiant
> lies highest above the horizon in a dark sky. Any meteor from Cetus or
> southern Pisces could be a candidate from this source. Rates should
> be close to 1 per hour from most locations.
>
> The Perseids are just now coming to life with perhaps 1 Perseid meteor
> visible every few hours in the morning sky. The radiant location is at
> 00:48 (012) +51 which places it in southern Cassiopeia approximately 10
> degrees north of the Great Andromeda Galaxy. This area of the sky is
> highest just before dawn so this would be the best time to try to see
> any Perseid activity. These meteors are swift except when seen near the
> radiant or near the horizon. They also produce many fine persistent
> trains. The Perseids with become much more active as we approach their
> August 12 maximum.
>
> The Sporadic rates for the Northern Hemisphere have bottomed out and
> will now finally begin to increase in July. One would expect to see
> perhaps 4 random meteors per hour during the last hours before dawn
> from rural observing sites. This estimate and the morning estimate for
> the Southern Hemisphere does not include the apex meteors listed above
> but is reduced due to moonlight. During the evening hours perhaps 2
> random meteors can be seen per hour from the Northern Hemisphere. Rates
> seen from the Southern Hemisphere are still slightly better than those
> seen in the Northern with perhaps 5 random meteors being seen per hour
> during the late morning hours and 3 per hour during the evening.
>
> Clear Skies!
> Robert Lunsford
> AMS Visual Program Coordinator
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