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Astronomy Calendar of Celestial Events 2011
Astronomy Calendar of Celestial Events 2011
 
The Astronomy calendar includes data for some general celestial events during 2011. In all reports, times and dates are in standard time for Sofia, Bulgaria. More reports generated by Astronomy Lab 2 for Windows, marked on the page as astron. lab. In all reports, times and dates are in standard time for Sofia, Bulgaria
or explicit is written Universal Time (UT). Times are in 24 hour format.
 
Sofia
Latitude:           42°41'05" N
Longitude:        23°19'10" E
Elevation: 560 meters,Local Time = UT +   2:00 hours.
 
 
Abbreviations used in reports:
 
AU                              – Astronomical Units (~150 000 000 km)
D                                 – Degrees
DEC                            – Declination
DIST                           – Distance
DSO                           – December Solstice
E                                 – East
FM                              – Full Moon
FQ                              – First Quarter Moon
H                                 – Hours
ILL FR,
ILLUM FRAC            – Illuminated Fraction
JSO                             – June Solstice
KM                             – Kilometers
LE                               – Lunar Eclipse
LQ                              – Last Quarter Moon
M                                – Minutes
MEQ                           – March Equinox
MR                             – Moon Rise
MS                              – Moon Set
N                                – North
NM                             – New Moon
RA                              – Right Ascension
S                                 – South, Seconds
SE                               – Solar Eclipse
SEQ                            – September Equinox
SR                               – Sunrise
SS                               – Sunset
UT                              – Universal Time
W                                – West
ZHR                            – Zenithal Hourly Rate
 
 
 
Sofia,Bulgaria
Latitude:            42°41'05" N
Longitude:        23°19'10" E
Local Time = UT + 2:00 hours
Elevation:         560 meters
 
 
Seasons 2011
 

 
data
hour
length
March Equinox
20 Mar 2011
23:19 UT
Winter Length       88,99 days
June Solstice
21 Jun 2011
17:15 UT
Spring Length        92,75 days
September Equinox
23 Sep 2011
09:03 UT
Summer Length     93,66 days
December Solstice
22 Dec 2011
05:31 UT
Autumn Length     89,85 days

astron. lab
 
Dates of Easter (2010 – 2015)
 
23 Mar 2008
12 Apr 2009 
04 Apr 2010 
24 Apr 2011
08 Apr 2012
31 Mar 2013
20 Apr 2014
05 Apr 2015
astron. lab 
 
 
    European Summer Time 
European Summer Time is the arrangement in Europe by which clocks are advanced by one hour in Spring to make the most of seasonal daylight. This is done in all of the countries of Europe except Iceland which observes Greenwich Mean Time (GMT) all year round. In the European Union this period extends from 01:00 GMT on the last Sunday in March until 01:00 GMT on the last Sunday in October each year. Europe is not currently observing Summer Time.
 
Exact timing in the next several years:
European Summer Time begins (clocks go forward) at 01:00 GMT on
28 March 2010
27 March 2011
25 March 2012
31 March 2013
 
European Summer Time ends (clocks go backward) at 01:00 GMT on
31 October 2010
30 October 2011
28 October 2012
27 October 2013
 
       World Time Zone
A time zone is a region of the earth that has uniform standard time, usually referred to as the local time. By convention, time zones compute their local time as an offset from UTC (see also Greenwich Mean Time). Local time is UTC plus the current time zone offset for the considered location.
 
 
On the figure is a map of standard time zones of the world as of June 2008.
 
more links:
http://www.timezonecheck.com/
http://24timezones.com/ 
http://www.usno.navy.mil/USNO/astronomical-applications
 
Summer time or daylight saving time (DST) is the practice of advancing clocks so that afternoons have more daylight and mornings have less. Typically clocks are adjusted forward one hour near the start of spring and are adjusted backward in autumn. Modern DST was first proposed in 1895 by George Vernon Hudson, a New Zealand entomologist.  Many countries using it but not all absolutely.
The practice is controversial. Adding daylight to afternoons benefits retailing, sports, and other activities that exploit sunlight after working hours, but causes problems for farming, evening entertainment and other occupations tied to the sun. Traffic fatalities are reduced when there is extra afternoon daylight; its effect on health and crime is less clear. Although an early goal of DST was to reduce evening usage of incandescent lighting, formerly a primary use of electricity, modern heating and cooling usage patterns differ greatly, and research about how DST currently affects energy use is limited and often contradictory. Although not used by most of the world's people, daylight saving time is common in high latitudes (bellow).
 
Map of countries who use or not DST around the world
 
Russia changed its position on the use of DST in year 2011.
 
The new map of countries who use or not DST around the world 2011.
 
 
     DST used
     DST no longer used
     DST never used
 
more info:
http://en.wikipedia.org/wiki/Daylight_saving_time
 
     Lunar Eclipses Report for 2011 (astron.lab)
   Total Lunar eclipse on 15. 6.2011
Moon rise: 17:56 UT
Moon set: 02:10 UT
Sun rise: 02:48 UT
Sun set: 18:06 UT.
Magnitude: 1,71
Partial phase begins:    18:23 UT
Total phase begins:      19:22 UT
Time of maximum eclipse: 20:12 UT
Total phase ends:        21:03 UT
Partial phase ends:      22:03 UT
The total lunar eclipse is visible from much of the Asia, Africa, East Europe, and West Australia.
The eclipse is visible from the territory of Bulgaria, beginning during of twilight.
 
 
  Total Lunar eclipse on 10.12.2011
Moon rise: 14:51 UT
Moon set: 05:30 UT
Sun rise: 05:46 UT
Sun set: 14:53 UT
Magnitude: 1,11
Partial phase begins:    12:46 UT
Total phase begins:      14:06 UT
Time of maximum eclipse: 14:31 UT
Total phase ends:        14:57 UT
Partial phase ends:      16:18 UT
The total lunar eclipse is visible from much of the Asia, Australia, East Africa, East Europe, and West North America.
The eclipse is visible from the territory of Bulgaria, beginning 2 hour before Sunset and continues during of twilight.
 
                     
 
Solar Eclipse Report for 2011 (astron.lab)
 
  Partial Solar eclipse on 04. 1.2011
Sun rise: 05:57 UT
Sun set: 15:06 UT
First contact:                    07:03 UT
Time of maximum eclipse: 08:27 UT
Last contact:                    10:02 UT
Maximum magnitude = 0,86 (Copenhagen = 0.83)
Eclipse is visible in the northern hemisphere (Europe, West Asia, and North-East Africa).
The eclipse is visible from Bulgaria with maximum eclipse magnitude ~0.74.
 
 
  Partial Solar eclipse on 01. 6.2011
Sun rise: 02:52 UT
Sun set: 17:58 UT
First contact:                    19:25 UT
Time of maximum eclipse: 21:16 UT
Last contact:                    23:07 UT
Maximum magnitude = 0,60
Eclipse is visible in the northern hemisphere (North America and East-North Asia).
The eclipse is invisible from territory of Bulgaria.
 
  Partial Solar eclipse on 01. 7.2011
Sun rise: 02:52 UT
Sun set: 18:09 UT
Time of maximum eclipse: 08:37 UT
Maximum magnitude = 0,10
Eclipse is visible in the southern hemisphere (the Antarctic Ocean).
The eclipse is invisible from territory of Bulgaria.
 
 
  Partial Solar eclipse on 25.11.2011
Sun rise: 05:30 UT
Sun set: 14:57 UT
Time of maximum eclipse: 06:24 UT
Maximum magnitude = 0,90
Eclipse is visible in the southern hemisphere (small part of South Africa, Antarctica, Tasmania and most of New Zealand).
The eclipse is invisible from territory of Bulgaria.
 
more links:
http://eclipse.gsfc.nasa.gov/OH/OH2011.html#SE2011Jan04P
 
  
    Planets Data (solar system)
 
Planet            Mean Dist        Period of           Period of          Orbit Inclin.       Axis Inclin.        Equatorial
           from Sun        Revolution         Revolution        to Ecliptic           to Ecliptic        Diameter
giants             AU                 around the Sun  around its axis            °                      °                km
 
Mercury           0.39                 87.96 days       58.65 days          7.01°                 0.1°                4880
Venus              0.72               224.70days     -243.02 days          3.39°             177°                  12104
Earth               1.00               365.26days          0.997 days        0.0°                 23°                  12756
Mars               1.52               686.98days          1.03 days          1.85°               25°                    6794
Jupiter             5.20                11.86 years         9.91 hours        1.31°                 3°                 142980
Saturn             9.54                29.46 years        10.23 hours        2.49°               27°                 120540
Uranus           19.18                84.01 years      -17.90 hours        0.77°               98°                   51120
Neptune         30.06              164.79 years       16.11 hours        1.77°                30°                   49500
 
 
Planet            Mean Dist       Period of             Period of          Orbit Inclination         Equatorial
                      from Sun        Revolution           Revolution          to Ecliptic               Diameter
dwarfs              AU              around the Sun    around its axis                 o                       km
 
Ceres                2.77               4.60 year            9.12 hours           10.59°                         974.6
Pluto               39.48            248.09 years        -6.39 days             17.14°                     ~2300.0
Haumea          43.34            285.40days                ???                 28.19°                     ~1150.0
Makemake      45.79            309.90days               ???                  28.96°                     ~1500.0
Eris                67.67            557.00days            7.2 hours?           44.19°                     ~2400.0
 
 
 
    Equation of time graph for 2011 (Bulgaria) 
The equation of time is the difference between apparent solar times and mean solar times, both taken at a given place (or at another place with the same geographical longitude) at the same real instant of time.
 
 
Apparent (or true) solar time can be obtained for example by measurement of the current position (hour angle) of the Sun, or indicated (with limited accuracy) by a sundial. Mean solar time, for the same place, would be the time indicated by a steady clock set so that its differences over the year from apparent solar time average to zero (with zero net gain or loss over the year).
The equation of time varies over the course of a year, in a way that is almost exactly reproduced from one year to the next. Apparent time, and the sundial, can be ahead (fast) by as much as 16 min 33 s (around 3 November), or behind (slow) by as much as 14 min 6 s (around 12 February).
The equation of time results mainly from two different superposed astronomical causes (explained below), each causing a different non-uniformity in the apparent daily motion of the Sun relative to the stars, and contributing a part of the effect:
the obliquity of the ecliptic (the plane of the Earth's annual orbital motion around the Sun), which is inclined by about 23.44 degrees relative to the plane of the Earth's equator; and the eccentricity and elliptical form of the Earth's orbit around the Sun.
The equation of time is also the east or west component of the analemma, a curve representing the angular offset of the Sun from its mean position on the celestial sphere as viewed from Earth.
The equation of time was used historically to set clocks. Between the invention of accurate clocks in 1656 and the advent of commercial time distribution services around 1900, one of two common land-based ways to set clocks was by observing the passage of the sun across the local meridian at noon. The moment the sun passed overhead, the clock was set to noon, offset by the number of minutes given by the equation of time for that date. (The second method did not use the equation of time; it used stellar observations to give sidereal time, in combination with the relation between sidereal time and solar time.) The equations of time values for each day of the year, compiled by astronomical observatories, were widely listed in almanacs and ephemerides.
Naturally, other planets will have an equation of time too. On Mars the difference between sundial time and clock time can be as much as 50 minutes, due to the considerably greater eccentricity of its orbit. 
 
 
Solar elevation angle 
This is the elevation angle of the sun. That is, the angle between the direction of the geometric center of the sun's apparent disk and the (idealized) horizon. It can be calculated, to a good approximation, using the following formula:
 
                   sin Θs = cosh cosδ cosΦ + sinδ sinΦ
where:
Θs - is the solar elevation angle
h - is the hour angle, in the local sidereal time.
δ - is the current Sun declination;   Φ - is the local latitude
 
Maximum elevation angle of the Sun during the year 2011.
 
Solar azimuth angle
The solar azimuth angle is the azimuth angle of the sun. It is most often defined as the angle between the line from the observer to the sun projected on the ground and the line from the observer due south. A positive azimuth angle generally indicates the sun is east of south, and a negative azimuth angle generally indicates the sun is west of south. Others define solar azimuth as the angle from due north in a clockwise direction as well.
It can be calculated, to a good approximation, using the following formula, however angles should be interpreted with care due to the inverse sine. For example: x = sin-1(y) has more than one solution, therefore at a northern latitude in summer, when the azimuth at sunrise should be a positive number greater than 90 degrees, inverse of sine will incorrectly yield an angle between 0 and 90 degrees that has the same sine.
 
                          sinΦs = (-sinh cosδ) / cosΘs
The following two formulas can also be used to approximate the solar azimuth angle, however because these formulas utilize cosine, the azimuth angle will always be positive, and therefore, should be interpreted as the angle east of south when the hour angle, h, is negative (morning) and the angle west of south when the hour angle, h, is positive (afternoon).
 
                          cosΦs = (cosh cosδ sinΦ – sinδ cosΦ) / cosΘs
                          
                          cosΦs = (sinΘs sinΦ – sinδ) / (cosΘs cosΦ)
 
The previous formulas use the following terminology:
Θs - is the solar elevation angle; h - is the hour angle of the present time
δ - is the current sun declination; Φ - is the local latitude
 
On the figure bellow is shown the solar azimuth angle for the year 2011.
 
 
Day length 
Day length refers to the time each day from the moment the upper limb of the sun's disk appears above the horizon during sunrise to the moment when the upper limb disappears below the horizon during sunset. Due to the diffusion and refraction of sunlight by the atmosphere, there is actually daylight even when the sun is slightly below the horizon. The period when it is still light even though the sun is below the horizon is called twilight.
In general, the length of a day varies throughout the year, and depends upon latitude. This variation is caused by the tilt of the Earth's axis of rotation with respect to the ecliptic plane of the earth around the sun (this angle is 23o26’).
 
Day length for 2011 is calculated and shown on the figure bellow.
 
 
 
    Twilight Report for 01.1.2011 to 31.12.2011 (astron.lab)
Universal Time
Date             Sun             Astronomical  Nautical       Civil
                  Rise    Set     Begin   End   Begin End     Begin End
 
01. 1.2011   05:57 15:03   04:10 16:50   04:44 16:16   05:20 15:41
08. 1.2011   05:57 15:10   04:11 16:56   04:45 16:22   05:20 15:47
15. 1.2011   05:55 15:18   04:10 17:03   04:43 16:29   05:18 15:54
22. 1.2011   05:50 15:26   04:07 17:10   04:40 16:37   05:15 16:02
29. 1.2011   05:45 15:35   04:02 17:18   04:36 16:44   05:09 16:11
05. 2.2011   05:37 15:45   03:56 17:26   04:29 16:53   05:03 16:19
12. 2.2011   05:29 15:54   03:49 17:34   04:22 17:01   04:55 16:28
19. 2.2011   05:19 16:03   03:40 17:42   04:13 17:09   04:45 16:36
26. 2.2011   05:08 16:12   03:30 17:50   04:02 17:18   04:35 16:45
05. 3.2011   04:57 16:21   03:19 17:59   03:51 17:26   04:24 16:53
12. 3.2011   04:45 16:29   03:07 18:07   03:40 17:34   04:12 17:02
19. 3.2011   04:33 16:37   02:54 18:16   03:27 17:43   04:00 17:10
26. 3.2011   04:20 16:45   02:40 18:25   03:15 17:51   03:48 17:18
02. 4.2011   04:08 16:53   02:26 18:35   03:01 18:00   03:35 17:26
09. 4.2011   03:56 17:01   02:12 18:45   02:48 18:09   03:23 17:35
16. 4.2011   03:45 17:09   01:58 18:56   02:35 18:19   03:11 17:43
23. 4.2011   03:34 17:17   01:43 19:08   02:23 18:28   02:59 17:52
30. 4.2011   03:23  17:25   01:29 19:19   02:10 18:38   02:48 18:01
07. 5.2011   03:14 17:33   01:16 19:32   01:59 18:48   02:38 18:10
14. 5.2011   03:06 17:41   01:03 19:44   01:49 18:58   02:29 18:18
21. 5.2011   02:59 17:48   00:51 19:56   01:39 19:08   02:21 18:26
28. 5.2011   02:54 17:54   00:41 20:07   01:32 19:16   02:15 18:33
04. 6.2011   02:50 18:00   00:34 20:17   01:27 19:24   02:11 18:40
11. 6.2011   02:48 18:04   00:29 20:24   01:23 19:29   02:08 18:45
18. 6.2011   02:48 18:07   00:27  20:29   01:23 19:33   02:08 18:48
25. 6.2011   02:50 18:09   00:28 20:30   01:24 19:35   02:09 18:49
02. 7.2011   02:53 18:08   00:33 20:28   01:28 19:33   02:13 18:49
09. 7.2011   02:57 18:06   00:41 20:23   01:34 19:30   02:18 18:46
16. 7.2011   03:03 18:02   00:50 20:15   01:41 19:24   02:24 18:41
23. 7.2011   03:09 17:57   01:01 20:05   01:49 19:17   02:31 18:35
30. 7.2011   03:16 17:50   01:13 19:53   01:58 19:07   02:39 18:27
06. 8.2011   03:23 17:42   01:25 19:40   02:08  18:57   02:47 18:18
13. 8.2011   03:31 17:32   01:37 19:26   02:18 18:45   02:55 18:08
20. 8.2011   03:38 17:22   01:48 19:12   02:27 18:33   03:03 17:56
27. 8.2011   03:46 17:10   01:59 18:57   02:36 18:20   03:12 17:44
03. 9.2011   03:53 16:59   02:09 18:43   02:45 18:07   03:20 17:32
10. 9.2011   04:01 16:46   02:19 18:28   02:54 17:53   03:28 17:19
17. 9.2011   04:08 16:34   02:28 18:14   03:02 17:40   03:35 17:07
24. 9.2011   04:16 16:21   02:37 18:00   03:10 17:27   03:43  16:54
01.10.2011   04:23 16:09   02:45 17:47   03:18 17:14   03:51 16:42
08.10.2011   04:31 15:57   02:53 17:35   03:26 17:02   03:58 16:30
15.10.2011   04:39 15:45   03:01 17:23   03:34 16:51   04:06 16:18
22.10.2011   04:48 15:34   03:09 17:13   03:41 16:40   04:14 16:08
29.10.2011   04:56 15:24   03:17 17:04   03:49 16:31   04:22 15:58
05.11.2011   05:05 15:15   03:24 16:56   03:57 16:23   04:31 15:49
12.11.2011   05:14 15:07   03:32 16:49   04:05 16:16   04:39 15:42
19.11.2011   05:23 15:01   03:39 16:44   04:13 16:11   04:47 15:37
26.11.2011   05:31 14:56   03:46 16:41   04:20 16:07   04:55 15:33
03.12.2011   05:39 14:54   03:53 16:40   04:27 16:06   05:02 15:31
10.12.2011   05:46 14:53   03:59 16:40   04:33 16:06   05:08 15:30
17.12.2011   05:51 14:54   04:04 16:41   04:38 16:07   05:14 15:32
24.12.2011   05:55 14:57   04:07 16:45   04:42 16:10   05:17 15:35
31.12.2011   05:57 15:02   04:10 16:49   04:44 16:15   05:20 15:40
 
 
    Moon Apsides Report for 01. 1.2011 to 31.12.2011 (astron.lab)
Universal Time
Date          Hour    Apsis      Distance (km)    Diameter
 
10. 1.2011     6      Apogee     404977           0,4918°
22. 1.2011     0      Perigee     362792           0,5490°
06. 2.2011    23     Apogee     405911           0,4906°
19. 2.2011     7      Perigee     358273           0,5559°
06. 3.2011     8      Apogee     406586           0,4898°
19. 3.2011    19     Perigee     356600           0,5585°
02. 4.2011     9      Apogee     406656           0,4897°
17. 4.2011     6      Perigee     358101           0,5561°
29. 4.2011    18     Apogee     406045           0,4905°
15. 5.2011    11     Perigee     362139           0,5499°
27. 5.2011    10     Apogee     405018           0,4917°
12. 6.2011     2      Perigee     367185           0,5424°
24. 6.2011     4      Apogee     404282           0,4926°
07. 7.2011    14     Perigee     369558           0,5389°
21. 7.2011    23     Apogee     404370           0,4925°
02. 8.2011    21     Perigee     365772           0,5445°
18. 8.2011    16     Apogee     405177           0,4915°
30. 8.2011    18     Perigee     360868           0,5519°
15. 9.2011     7      Apogee     406064           0,4905°
28. 9.2011     1      Perigee     357566           0,5570°
12.10.2011    12    Apogee     406432           0,4900°
26.10.2011    13    Perigee     357066           0,5578°
08.11.2011    13    Apogee     406181           0,4903°
23.11.2011    23    Perigee     359702           0,5537°
06.12.2011     1     Apogee     405410           0,4912°
22.12.2011     3     Perigee     364798           0,5459°
 
 
 
Main meteor showers for 2011
 
 
Shower name
 
Maximum
 
ZHR* at maximum
 
Illumin.fraction
 
V (km/s)
 
Constellation radiating
 
Parent Comet
 
Quadrantids
(northern hemisphere)
 
January 4
 
80
 
0.00
 
41
 
Bootes
 
 
Lyrids
 
April 23
 
12
 
0.71
 
48
 
Lyra
 
C/1861 G1/Thatcher
 
Eta Aquarids
 
May 6
 
10
 
0.07
 
66
 
Aquarius
 
1P/Halley
 
eta Lyrids
 
June 15
 
10
 
0.66
 
31
 
Lyra
 
C/1983 H1 
 
Delta Aquarids
(Southern hemisphere)
 
July 30
 
20
 
0.01
 
41
 
Aquarius
 
Unknown
 
Capricornids
 
July 29
 
4
 
0.05
 
23
 
Capricornus
 
45P 
 
Perseids
 
August 13
03:04 UT
 
75
 
0.99
 
59
 
Perseus
 
109P/Swift-Tuttle
 
Draconids
 
October 8-9
 
8
 
0.92
 
23
 
Draco
 
21P/Giacobini-Zinner
 
Orionids
 
October 23
 
25
 
0.21
 
67
 
Orion
 
1P/Halley
 
Leonids
 
November 18
 
10
 
0.57
 
71
 
Leo
 
55P/Tempel-Tuttle
 
Geminids
 
December 15
 
75
 
0.81
 
35
 
Gemini
 
3200 Phaethon
 



 

 

 

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