Solar System Observing at AHSP

Revised June 24, 2017

Here is a summary of Solar System Observing during AHSP 2017. This will give you an idea of events and times during the weekend for overall planning purposes.

Almanac for AHSP2017

[content is correct, editing is in process]

About the sky generally

Sky Maps from <https://www.fourmilab.ch/cgi-bin/Yoursky>

• Early night (2130), color
• Late night (0530), color
• Early night (2130), black on white
• Late night (0530), black on white

Julian date conversion

The following are equivalent:

   2017 Jul 22 00:00:00 UT
   2017 Jul 21 20:00:00 EDT
   J.D. 2457956.5

Sun

For Elkins, Randolph County, WV (Longitude W79° 51′, Latitude N38° 56′)

From USNO                                     

      Date         Begin      Rise  Az.   Transit Alt.    Set  Az.     End
     (EDT)         Civil                                              Civil 
                  Twilight                                           Twilight
                     h  m     h  m   °      h  m  °       h  m   °      h  m

2017 Jul 21 (Fri)   05:41    06:11  63     13:26 71S     20:40 297     21:11     
2017 Jul 22 (Sat)   05:41    06:12  63     13:26 71S     20:39 297     21:10     
2017 Jul 23 (Sun)   05:42    06:13  63     13:26 71S     20:39 297     21:09     
2017 Jul 24 (Mon)   05:43    06:14  63     13:26 71S     20:38 296     21:08     
2017 Jul 25 (Tue)   05:44    06:14  64     13:26 71S     20:37 296     21:07     

Civil twilight is while the Sun is <6deg° below horizon    ~30 min

Nautical twilight is while Sun is 6-12° below horizon      ~70 min

Astronomical twilight is while Sun is 12-18°

below horizon      ~110 min

Moon

      Date (EDT)          Rise  Az.      Transit Alt.       Set   Az.
                          h  m   °         h  m  °          h  m   °

2017 Jul 21 (Fri)        04:18  65        11:41 70S        19:04 295                
2017 Jul 22 (Sat)        05:20  65        12:43 70S        20:03 294                
2017 Jul 23 (Sun)        06:26  67        13:43 68S        20:54 291                
2017 Jul 24 (Mon)        07:34  70        14:40 65S        21:39 287                
2017 Jul 25 (Tue)        08:42  75        15:34 61S        22:18 282                

Phase of the Moon on July 23, 2017: New Moon at 5:46 a.m. (local daylight time)

Planets

Naked-eye planets

Mercury     evening, close to Sun
Venus       morning
Mars        close to Sun
Jupiter     evening
Saturn      evening

From Heavens Above     http://heavens-above.com/PlanetSummary.aspx

Date/Time:          2017  JUL 23 00:00:00 EDT             

Location: SKMC (38.6832°N, 79.5603°W) 1234m

Mercury

Venus

Mars

Jupiter

Saturn

Uranus

Neptune

Pluto

Right ascension

9h 54m 30.4s

5h 17m 26.4s

8h 15m 53.0s

12h 59m 31.6s

17h 24m 36.2s

1h 45m 44.9s

23h 1m 15.2s

19h 15m 43.0s

Declination

12° 43' 8"

21° 4' 43"

20° 53' 34"

-5° 2' 1"

-21° 54' 31"

10° 18' 10"

-7° 16' 23"

-21° 32' 48"

Range (AU)

0.976

1.085

2.653

5.618

9.245

19.858

29.202

32.380

Elongation from Sun

26.1°

40.2°

1.6°

75.4°

141.5°

92.0°

136.6°

167.3°

Brightness

0.2

-3.9

1.7

-1.8

0.2

5.8

7.8

14.2

Equatorial Diameter

6.89"

15.38"

3.53"

35.09"

17.98"

3.55"

2.34"

0.10"

Phase Angle

81.9°

64.8°

1.0°

10.4°

3.6°

2.9°

1.3°

0.4°

Constellation

Leo

Taurus

Cancer

Virgo

Ophiuchus

Pisces

Aquarius

Sagittarius

Meridian transit

15:09

10:32

13:29

18:11

22:35

06:59

04:14

00:30

Rises

08:28

03:20

06:18

12:28

17:51

00:26

22:35

19:40

Sets

21:49

17:44

20:39

23:54

03:23

13:31

09:50

05:15

Asteroids

Asteroids with oppositions around AHSP2017

Designation Month Day   Hour  Mag.  Telescope

6 Hebe      JUN   17    3     9.6   60mm  
28 Bellona  JUN   21    19    11.8  8
40 Harmonia JUN   23    12    9.4   60mm
76 Freia    JUN   28    5     13.6  16    
10 Hygiea   JUN   29    19    9.2   60mm
5 Astraea   JUL   2     2     11.0  6     
3 Juno      JUL   2     13    10.1  3     
69 Hesperia JUL   13    22    12.4  10    
78 Diana    JUL   21    13    12.8  12    
23 Thalia   AUG   6     4     12.0  8     
25 Phocaea  AUG   11    6     10.6  4.25 

http://heavens-above.com/Asteroids.aspx?lat=38.6832&lng=-79.5603&loc=Circleville&alt=1234&tz=EST

Asteroid occultations — none

Comets

Check for update:

http://heavens-above.com/Comets.aspx?lat=38.6832&lng=-79.5603&loc=Circleville&alt=1234&tz=EST 

Meteors

 — no major showers

Calculating sidereal time during AHSP

Given below is a simple algorithm for computing apparent sidereal time to an accuracy of about 0.1 second, equivalent to about 1.5 arcseconds on the sky. The input time required by the algorithm is represented as a Julian date (Julian dates can be used to determine Universal Time.)

Let JD be the Julian date of the time of interest.  Let JD₀ be the Julian date of the previous midnight (0 h) UT (the value of JD₀ will end in .5 exactly), and let H be the hours of UT elapsed since that time. Thus we have JD = JD₀ + H/24.

For both of these Julian dates, compute the number of days and fraction (+ or -) from 2000 January 1, 12h UT, Julian date 2451545.0:

D = JD – 2451545.0
D₀ = JD₀ – 2451545.0

Then the Greenwich mean sidereal time in hours is

GMST = 18.697374558 + 24.06570982441908 D

It will be necessary to reduce GMST to the range 0h to 24h. Setting H = 0 in the above formula yields the Greenwich mean sidereal time at 0h UT.

The equations for GMST given above are adapted from those given in Appendix A of USNO Circular No. 163 (1981).

Add el/az of the Sun for Elkins from 1500-1600 EDT every 5 min for Sat/Sun for navigation demonstration.