Hi,

I used my planeterium software package The Sky (Software Bisque) for Mars at 
your location and todays date and it came up with following data:

Mars
Rise: 16:37  Transit: 23:53  Set: 07:15
RA:17h 19m 39.6s  Dec:-26d 40' 48" 
Azm:77d 05' 09"  Alt:+71d 30' 08" with Refraction: +71d 30' 28" 
Phase:99,773 Apparent magnitude:-2,34
Heliocentric ecliptical coordinates :
   l=265d 51' 18.2"  b=01d 05' 40.6"  r=1,463930 
Geometric geocentric ecliptical coordinates :
   l=+260d 58' 59"  b=-03d 33' 27"  r=0,450762 
Mean geometric ecliptical coordinates :
   l=+260d 58' 42"  b=-03d 33' 26"  r=0,450768 
True Equatorial:  RA=17h 19m 39s   Dec=-26d 40' 50" 
Physical Data
  Dec. Earth = 4,05d, Dec. Sun = -0,34d
Position angle:
Longitude of central meridian:  : 202,28
Defect of illumination:  : 0,05 Position angle:  : 67,32
Apparent angular diameter : 20,76

I assumed that you are in the UT-7 hour time zone (Mountain) and on DST

Take care and good observing,

PS: Here in Santiago (33.5 S - 70.5 W) Mars culminates practically in the 
zenith and it's a beautiful sight in my AP155 refractor (6"-f/7).

Daniel VERSCHATSE 


 >>  Hi Gianni and others:

 >>  The summer solstice will be a little unusual this year because several
 >>  astronomical events will occur on this day.  There will be a total eclipse
 >>  of the sun (in Africa), and Mars will be in conjunction with the Earth.
 >>  (It
 >>  will be at its closest distsance in many many years).  Because a total
 >>  solar
 >>  eclipse  implies a new moon, the sky will be nice and dark for viewing
 >>  Mars.

 >>  The night of June 21, I'd like to look at Mars with the telescope (I saw
 >>  it
 >>  last night, it's really big!). Since Mars is low in the Southern sky, near
 >>  Scorpio, optimal viewing conditions will be when Mars is at culmination (
 >>  its highest alititude above atmospheric interference along the horizon).

 >>  This will happen sometime in the early morning hours I think.  Here's my
 >>  question :  How can I determine the time of culmination of Mars for June
 >>  21
 >>  at Latitude 32.5*N, Longitude 111*W?  I need to set the alarm clock!

 >>  Thanks
 >>  John

 >>  John L. Carmichael Jr.
 >>  Sundial Sculptures
 >>  925 E. Foothills Dr.
 >>  Tucson Arizona 85718
 >>  USA

 >>  Tel: 520-696-1709
 >>  Email: [EMAIL PROTECTED]
 >>  Website: <http://www.sundialsculptures.com>
 >>  ----- Original Message -----
 >>  From: "Gianni Ferrari" <[EMAIL PROTECTED]>
 >>  To: "Sundial Mail List" <[email protected]>;
 >>  <[EMAIL PROTECTED]>
 >>  Sent: Monday, June 18, 2001 2:45 AM
 >>  Subject: R: meridian or culmination ?


 >>  > Hallo Alain,
 >>  >
 >>  > in astronomy the two words "meridian passage" and "culmination" are
 >>  > (almost) synonymous and therefore I think  that, in the software of
 >>  which
 >>  > you speak, they are used for the same phenomenon.
 >>  >
 >>  > In  page 724 of the Explanatory Supplement to the Astronomical Almanac
 >>  we
 >>  > may read:
 >>  > " CULMINATION : culmination passage of a celestial object across the
 >>  > observer's meridian;
 >>  > also called "meridian passage." More precisely, culmination is the
 >>  passage
 >>  > through the point of greatest altitude in the diurnal path. Upper
 >>  > culmination (also called "culmination above pole" for circumpolar stars
 >>  and
 >>  > the Moon) or transit is the crossing closer to the observer's zenith.
 >>  Lower
 >>  > culmination (also called "culmination below pole" for circumpolar stars
 >>  and
 >>  > the Moon) is the crossing farther from the zenith."
 >>  >
 >>  > The height above the horizon at upper culmination of a celestial body
 >>  with
 >>  > Declination = d   is    H_uc = 90 - Lat + d (measured from  South) or =
 >>  90
 >>  +
 >>  > Lat - d    if measured from North
 >>  >
 >>  > For example  with Lat = 50d , if the declination of the Sun is d = 20d ,
 >>  we
 >>  > have H_uc=60 d (measured from South)
 >>  > For a star with declination = 80d  we have H_uc=60d measured by North
 >>  >
 >>  > The height above the horizon at lower culmination of a celestial body
 >>  with
 >>  > Declination = d is
 >>  > H_lc = Lat + d - 90 (measured from North)
 >>  >
 >>  > For example with Lat = 50d, if the declination of the Sun is d = 20d ,
 >>  we
 >>  > have H_lc= -20d (the Sun is under the horizon)
 >>  > For a star with declination d = 80d, we have   H_lc=+40d
 >>  >
 >>  > For a place with Lat = 75d and with the Sun with d = 20d , we have at
 >>  upper
 >>  > culmination  H= +35 measured from South and at lower c.,  H = + 5
 >>  measured
 >>  > from  North (the Sun doesn't set)
 >>  >
 >>  > Regards -
 >>  >
 >>  > Gianni Ferrari
 >>  >
 >>  > ----- Original Message -----
 >>  > From: Alain MORY <[EMAIL PROTECTED]>
 >>  > To: <[email protected]>
 >>  > Sent: Saturday, June 16, 2001 10:25 PM
 >>  > Subject: meridian or culmination ?
 >>  >
 >>  >
 >>  > >
 >>  > > Hello,
 >>  > >
 >>  > > I was surprised to sea a software dedicated for astronomy showing
 >>  other
 >>  > > times for "passage au méridien" and for "culmination" of the sun.
 >>  > >
 >>  > > Why is there such a difference between these two notions ?
 >>  > >
 >>  > > Alain MORY
 >>  > > 48°N 7°E
 >>  > >
 >>  > >
 >>  >
 >>  >
 >>  >

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