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The Obiective View August 1998 Newsletter of the Northern Colorado Astronomical Society Thom Peck, President 962-9695 [email protected] Randy Moench, V Pres 493-7613 [email protected] Doug Moench Treasurer 221'-9455 [email protected] Tom Teters, Secretary 482-5702 [email protected] Randy Moenctu Web Site Editor WWW Page: http:/ /lamar.colostate.edu/-rmoench/ncasrdm.html David Chamness, A L correspondent 482-1794 Dan Laszlo, Newsletter Editor 498-9226 [email protected] Meetings first Thursday of each Month Next Meeting: August 6 7:30 pm Discovery Center Fort Collins " Establishing a Human Mission from Planet Earth: Technology Assessment and SocialForecasting of Moon/Mars Synergies " by CSU'sEligar Sadeh ** "* Club Businesswill precede the program, 7-7:30pm August 6 NCAS Meeting Directions Irily 2 Program: Supernovas, by Dave Chamness Discovery Center, 703E ProspectRd, Fort Collins From Loveland go North on US 287 to ProspectRd in Fort The largest visible remnant of a catastrophic supernova Collins, go East about 0.5 miles. Look for the Discovery is the Gum Nebula, seen from the Southern Hemisphere Center sign on the South side of the street. in the constellation Vela. It extends over 60 degrees of From I-25, take Exit 268, head West into Fort Collins. sky and is 1300 light-years away. The brightest Continue past Lemay Ave about 0.5 miles and see the supernovas rival galaxies in brightness, with an absolute Discovery Center on the left. magnitude of 20. This is 10e10times the Sun's brightness, a million times brighter than Cepheid variables. NCAS Star Party, August 21or 22, Stove Prairie Site Supernovas are estimated to occur in the Milky Way From the Stove Prairie Schoolgo 1.1 mile west and bear Galaxy three times per century, but only 10% are visible west(right) after the fence for a tenth or two. Tom will to us. A supernova can release2.3 x 10e30megatons (or put out the star party sign on the left side of that road. 10e53ergs, 10e46joules, 7x10e45foot-pounds). A Type I You can call 482-5702if the weather is in doubt. The supernova lacks hydrogen lines in its spectrum. Sixty-six Stove Prairie School intersection is 13 miles west from percent of supernovas are Type Ia. They occur when a Bellvue and over the Rist Canyon Road, while in place carbon-oxygen white dwarf is greater than 1.44 solar this is a steep road, the county takes VERY good care of massesand explodes. The explosion is the consequenceof it. If you're coming from the Loveland area use the a collapse which triggers carbon fusiort which releases Masonville Road, the S.P.S. is 14 miles from the the energy to blow the star apart. This type is the Masonville intersection. The site itself is at about 7500ft, brightest and most uniform. Its light curve peaks and it has a good open horizon (5*-10*), but not cacti or decays sharply. Debris rushes out at 10000 km/sec. services. So bring warm clothes, several layers. Be White dwarf stars in binary systems can steal mass from prepared!!! This site is allowed us through the auspices their companion stars and accumulate enough to create a of the land manager/owner, he wanted us to CALL before Type Ia supernova. The Veil Nebula in Cygnus is a we went up there and asked that we leave the site clean remnant of a Type Ia supernova. Type Ib occurswhen a and in the same condition as we found it. Call Tom Teters Wolf-Rayet star, 30x the Sun's mass, has collapse of its with questions about the star party status, site or dates, iron core within 1 second. It shrinks from Earth size to 10- 482-5702, or Email [email protected]. 20 km across. The explosion is driven by a neutrino shock wave. Neutrinos from the center heat up matter falling NCAS Events,from Randy Moench, Vice President iry and it bouncesou! ejectedat 1O000km/second. There September3 Gravity Waves Bill Massman is decay of 56-Nickel to 56-Cobalt to 56-Iron. A pulsar Other FRASC Events remnant is created, composed of a superfluid superdense Longmont Astronomical SocietyMeetings sea of neutrons. The Eta Carinae Nebula is illimunated 7:30 pm, Third Thursday, monthly by a Wolf-Rayet star of 100 solar masses. In 1843 it Longmont Christian School, 550 N Coffman St ejected 2 to 3 solar masses. It is now trying to lose its hydrogen envelope, trying to build an iron core and blow August 20-23 Weekend Under the Stars up. A Type IIb supernova has hydrogen lines, and occurs Foxparlg Wyoming with iron core collapse in a red or blue supergiant. They Contact Marty CurrarL 307-635-5944,Cheyenne WY range from 8 to 100solar masses.They occur only in spiral Web info at http:/ /users.sisna.com/mcurran galaxies. They have a wide range of properties, and the absolutemagnitude is minus 14 to minus 20. Expansionis "Cosmic Chameleon:The Supernova in M81", Astronom, 2000 to 20000 km/second. They show calcium, sodium, February1994 irory titanium, and selenium lines in the spectrum. Supernova 1987a was a Type II. Its neutrinos reached "Ka-Boom: How Stars Explode", Astronomy, July 1997 Eafth 7 hours before the optical brightening was visible. It was 160000 light-years away, absolutemagnitude -14, apparent magnitude 4.3. This apparent magnitude was Rocky Mountain National Park Star Parties, Upper the brightest we have seen in 383 years. The Type II BeaverMeadows light curve shows a more gradual decline from peak than Dates remaining are: August 14, August 28. Let Ken Type I. A supernova1.2light-years away, with absolute Vanlew know if you would like to take part this summer, magnitude -20 would appear as bright as our Sun does to 226-2500extension 8724. us. With its 15,000K temperature,we would be bathed in UV and neutrinos. A supernova 600 light-years away would appear magnitude -8 to -13, and if 5 solar masses August Observers'Guide, by Brad Jarvis were ejected, 6 pounds of material would hit the Earttu 20,000 years later. The spectrum shows a little helium August is the month of the mighty Perseid meteor and much silicon. Hubble images of SN1987anow show a shower. Over 50 meteorsper hour would be expectedon a set of rings, likely traced by the pulsar remnant, or a moonless night as Earth sweeps up debris from Comet manifestation of its magnetic field. The Crab Nebula Swift-Tuttle. The meteors appear to come out of the pulsar is 6300 light years away; it has a magnetic field constellation Perseut which will be in the northeast just 10e12 times the Earth's. The nebula is 16 light-years below Cassiopeia. Unfortunately, a 68% illuminated across and expanding by 50 million miles a day. Moon will be closeby after 11pm on the 12th. Supernova discoveries numbered about 1-2 a year from 1900 to 1950. There were about 20 a year from 1950 to The best occultation of a star by an asteroid visible this 199Oand in1997,137 were found. From Jan-Mar1998,27 month will be on the 13th at 11:35p.m. MDT. For 15 have been detected. The Australian amateur, Rev. seconds,87 km wide 576 Emanuela will pass in front of Robert Evans, has visually found more than a dozen by the magnitude 10.3 star GSC 11741.528at RA 23h50m03s, memorizing galaxy photos and reporting the new objects DEC +11d24m47s.At this time, Emanuelawill be 1.566 he spots. Spiral galaxies can host all three types of au from the Earth in its 5.2 year orbit and 98% supernova, but elliptical galaxies have no current star illuminated (but it will still be dim: Magnitude 13.2). formation and can only show one type. Dave also Expect the star to dim by the difference in their discussed the peculiar effects of the extreme density of magnitudes(3.1). white dwarf stars, pulsars, and black holes. Escape velocity from the Earth is 11.2km/second, but {or a white This month we will be looking at the region of the sky dwarf it is 4900 km/second. A nickel dropped on a white around the constellation Cygnus, the Swan (also known as dwarf would trigger a 20,000kiloton explosiory like the the Northern Cross). This area is dominated by large effect of 1500 tons dropped on the Earth. Escapevelocity dust clouds and newly born stars in the Galaxy's Orion for a pulsar is 20O000km/second, and for a black hole is Arm (of which we are a part) as it spirals out toward us. over 300,000 km/sec, so no light can escape it. More At the Tail of the swan is the first magnitude information on supernovascan be found on the Internet at spectroscopic binary star Deneb (RA 20h41m26s,DEC www.spa-garching.mpg.de/ -ewald / sn11 / sn11.htm. +45d16m49s;mag 1.25, dist 990 pc), and at its head is a Dave's talk was timely, given the pair of supernovae favorite of amateur astronomers,the double star Albireo within reach of small telescopesthis spring. (RA 19h30m43s,DEC +27d57m35s;mag 3.1v,dist 118pc). Albireo, nearly lost in the luminosity of the Milky Way, Bio Note: Dave Chamness has been interested in consistsof an easily viewed yellow star and blue star. astronomy since grade school, and had a 2.4 inch refractor in ]unior High. He is an engineer at Hewlett Packard One of the most spectacular sights in the sky is the Veil working on integrated circuit manufacturing. Other Nebula (part of which is NGC 6960,at RA 20h46m, DEC interests include travel, photography, and forecasting +30d39m),also known as the Cygnus Loop.
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