01 July 2013

Pole star on Different Planets


We have all seen night after night, season after season that one star in the north seems fixed in the sky. This is because the axis of earth rotation passes in the same line and so the star appears stationary; we call this star, pole star or Polaris. This star is the main star of constellation of Ursa Minor with a magnitude of 2. From Bangalore it will be 13degrees in altitude, remember that altitude of the pole star depends on latitude of the place. Here is a chart of the Polaris.

 
 
 
Now every planet rotates on its axis, so what will be the location of pole star for those planets in the solar system. Let’s begin with Mercury the closest to Sun, the location of pole star will be in constellation of Draco, the circle indicates the area where the Mercury pole star is located.
 
 
Venus:
 
We know that there is no way we can have an open sky to see the stars on Venus but based on the orbit orientation of the planet we can say that the pole star will be in the constellation of Draco. Here is the sky chart of the location for Venus pole star.
 
 
 
 
Mars:
The red planet we love to explore, we have seen the sunrise and sunset taken by the landing probes and also transit of Mars moon across Sun’s disk. If we were to find the pole star of Mars it will be in the constellation of Cygnus close to star Deneb.

 
Jupiter:
The giant planet rotates fast taking only 9h55m to complete one rotation, while all constellations and stars are moving at dizzying speed one star in Draco will remain still, as the polar axis of Jupiter lies in Draco constellation.
 
Saturn:
The ringed planet has its pole close to our own pole star. Here is a chart on location of the pole star seen from Saturn.
 
Uranus:
This unique planet rotating with high axis angle seems rotating on its belly. The pole star for this Planet would lie between Taurus and Orion.
 
 
Neptune:
Last among outer “planets” is the planet Neptune and it would have the pole star in the constellation of Cygnus.
 




24 April 2013

Timelapse showing no Shadow on Bangalore April 24 2013

This small time lapse taken today to show that when Sun's Declination and Latitude of the place are same the Sun will be directly overhead and there will minimum or no shadow at that place. Please refer to the previous post to know  on what date  your location will have no  shadow at noon


Days of No shadows at Noon

We have all heard the story on how Eratosthenes measured the circumference of the earth. Eratosthenes observed that during high noon when sun was at Zenith a well at a place called Syene did not cast any shadow on June 21st; we call this day as summer Solstice. On same day, Solstice, during high noon a shadow was cast when a vertical stick was kept in Alexandria. Based on the angle of shadow cast by the sun he calculated the circumference of the earth, he gave a value of 40233km.
Sun rises in the east and sets in the west, this we notice easily as the duration is very small. The Sun does move in north-south direction too, this we normally notice as seasonal changes more than position of the sun, as the movement of the Sun in north-south direction takes months together.
Sun will be directly overhead at equator on march21/22; the shadow will be at its minimum on that day during high noon. This day is called Equinox and Sun’s angle is taken as Zero degree declination.
As days pass, due to earth’s axis inclination of 23.5degrees, Sun starts moving towards north from March 21st to June 21st. On June 21st Sun would have reached maximum angle of 23.5degrees, this day is called summer Solstice, and after reaching north most angle Sun starts moving back towards equator. The Sun reaches back to zero declination, on September 22nd and this position is called autumn equinox. From this day Sun will move towards south reaching southernmost angle of -23.5 on December 21st, again after reaching this declination sun starts moving towards equator and cycle continues.
Now coming back to shadows, we have seen that there will be minimum or no shadow on equinox day on equator regions like Congo, Uganda and Kenya etc. All other regions not on equator or zero latitude will have shadows on that day. So when will other regions can have minimum or no shadow?
Here is good and easy way to know when the Sun will be directly overhead and there will no shadows in area we live. All we need to know is the declination of the sun and latitude of the place we live, on the day these two match; the Sun will be directly overhead at noon, with minimum or no shadow cast. That means we should live in a region which is less than or equal to 23.5degrees on either side of the equator.
Here is list of declination of the Sun; find out where and when there will be no shadow day based on latitude of your place….Make sure the reference is a vertical  pole or stick and time you check is at exact noon.
Bangalore will have minimum shadow on April 24/25th and again on Aug 19th.
Declination(Dec) is given in Degrees, Minutes and Seconds




  RA  Dec  
YearMonthDatehmso'"
2013Apr104120.3542649.6
2013Apr20445944957.3
2013Apr304837.851259.9
2013Apr405216.7753557.1
2013Apr505555.9155848.5
         
2013Apr605935.2562133.8
2013Apr71314.864412.6
2013Apr81654.587644.6
2013Apr911034.617299.3
2013Apr1011414.8975126.4
         
2013Apr1111755.4481335.6
2013Apr1212136.2783536.5
2013Apr1312517.485728.7
2013Apr1412858.8491912
2013Apr1513240.694045.9
         
2013Apr1613622.710210.1
2013Apr171405.14102324.3
2013Apr1814347.95104428.1
2013Apr1914731.1311521.2
2013Apr2015114.7111263.3
         
2013Apr2115458.68114634.1
2013Apr2215843.0812653.1
2013Apr232227.912270.2
2013Apr242613.17124655
2013Apr252958.913637.1
         
2013Apr2621345.113266.3
2013Apr2721731.8134522.2
2013Apr2822119.0114424.7
2013Apr292256.73142313.2
2013Apr3022854.99144147.6
         
2013May123243.791507.5
2013May223633.15151812.6
2013May324023.0815362.5
2013May424413.57155337.1
2013May52484.63161055.9
         
2013May625156.27162758.6
2013May725548.49164444.9
2013May825941.2917114.5
2013May93334.66171727
2013May103728.61173322.3
         
2013May1131123.13174859.8
2013May1231518.2218419.5
2013May1331913.87181920.9
2013May1432310.0918343.7
2013May153276.87184827.8
         
2013May163314.219232.7
2013May173352.08191618.3
2013May183390.5192944.2
2013May1934259.45194250.3
2013May2034658.94195536.1
         
2013May2135058.942081.5
2013May2235459.4720206.3
2013May233590.51203150.2
2013May24432.05204312.9
2013May25474.09205414.2
         
2013May264116.6321454
2013May274159.66211512
2013May2841913.1821257.9
2013May2942317.17213441.6
2013May3042721.63214352.9
         
2013May3143126.54215241.6
2013Jun143531.892217.4
2013Jun243937.6622910.3
2013Jun344343.83221650
2013Jun444750.422246.3
         
2013Jun545157.33223059.2
2013Jun64564.6223728.3
2013Jun75012.19224333.7
2013Jun85420.08224915.2
2013Jun95828.25225432.6
         
2013Jun1051236.67225925.8
2013Jun1151645.3123354.7
2013Jun1252054.1623759.3
2013Jun135253.18231139.4
2013Jun1452912.35231455
         
2013Jun1553321.64231746
2013Jun1653731.04232012.4
2013Jun1754140.52232214
2013Jun1854550.04232351
2013Jun1954959.623253.1
         
2013Jun205549.16232550.5
2013Jun2155818.7232613.1
2013Jun226228.21232610.9
2013Jun236637.66232544
2013Jun2461047.05232452.2
         
2013Jun2561456.34232335.7
2013Jun266195.52232154.5
2013Jun2762314.58231948.6
2013Jun2862723.5231718
2013Jun2963132.25231422.9
         
2013Jun3063540.8123113.4
2013Jul163949.1723719.4
2013Jul264357.2923311.1
2013Jul36485.15225838.7
2013Jul465212.74225342.1
         
2013Jul565620.03224821.7
2013Jul67026.99224237.4
2013Jul77433.61223629.4
2013Jul87839.86222958
2013Jul971245.7222233.2
         
2013Jul1071651.16221545.2
2013Jul1172056.182284.3
2013Jul127250.752200.6
2013Jul137294.84215134.2
2013Jul147338.45214245.5
         
2013Jul1573711.55213334.6
2013Jul1674114.1321241.7
2013Jul1774516.1821147
2013Jul1874917.6921350.8
2013Jul1975318.64205313.3
         
2013Jul2075719.02204214.7
2013Jul218118.84203055.3
2013Jul228518.08201915.2
2013Jul238916.7420714.6
2013Jul2481314.83195453.9
         
2013Jul2581712.34194213.3
2013Jul268219.27192913
2013Jul278255.61191553.2
2013Jul288291.3819214.2
2013Jul2983256.56184816.4
         
2013Jul3083651.15183359.9
2013Jul3184045.16181925.1
2013Aug184438.5718432.2
2013Aug284831.4174921.6
2013Aug385223.63173353.5
         
2013Aug485615.2617188.3
2013Aug5906.311726.1
2013Aug69356.75164547.5
2013Aug79746.61162912.6
2013Aug891135.87161221.8
         
2013Aug991524.55155515.5
2013Aug1091912.63153753.8
2013Aug119230.13152017.2
2013Aug1292647.0415225.9
2013Aug1393033.38144420.4
         
2013Aug1493419.1514260.8
2013Aug159384.3614727.6
2013Aug1694149.01134841
2013Aug1794533.12132941.3
2013Aug1894916.69131028.9
         
2013Aug1995259.7512514
2013Aug2095642.31123126.9
2013Aug2110024.38121138
2013Aug221045.98115137.5
2013Aug2310747.14113125.6
         
2013Aug24101127.8611112.8
2013Aug2510158.17105029.3
2013Aug26101848.08102945.4
2013Aug27102227.610851.4
2013Aug2810266.7794747.7
         
2013Aug29102945.5892634.6
2013Aug30103324.059512.3
2013Aug3110372.2184341.3
2013Sep1104040.068221.9
2013Sep2104417.638014.3
         
2013Sep3104754.9273819
2013Sep4105131.9571616.2
2013Sep510558.736546.4
2013Sep6105845.2963149.7
2013Sep711221.626926.7
         
2013Sep811557.7654657.7
2013Sep911933.7152422.9
2013Sep1011139.495142.7
2013Sep11111645.1143857.5
2013Sep12112020.64167.6
         
2013Sep13112355.9635313.3
2013Sep14112731.2333015
2013Sep1511316.413713
2013Sep16113441.532447.5
2013Sep17113816.6122059
         
2013Sep18114151.6815747.7
2013Sep19114526.7613433.9
2013Sep2011491.8711118
2013Sep21115237.040480.2
2013Sep22115612.302440.9
         
2013Sep23115947.670120.4
2013Sep2412323.160221
2013Sep2512658.8104523
2013Sep26121034.64-1845.1
2013Sep27121410.66-1327.1
         
2013Sep28121746.9-15528.6
2013Sep29122123.38-21849.3
2013Sep3012250.11-2428.7
2013Oct1122837.13-3526.6
2013Oct2123214.43-32842.6
         
2013Oct3123552.06-35156.4
2013Oct4123930.01-4157.4
2013Oct512438.31-43815.4
2013Oct6124646.98-5120
2013Oct7125026.03-52420.9
         
2013Oct812545.47-54717.5
2013Oct9125745.32-6109.6
2013Oct1013125.6-63256.7
2013Oct111356.32-65538.6
2013Oct1213847.5-71814.7
         
2013Oct13131229.16-74044.8
2013Oct14131611.32-838.4
2013Oct15131954-82525.3
2013Oct16132337.21-84735
2013Oct17132720.99-9937.2
         
2013Oct1813315.34-93131.5
2013Oct19133450.3-95317.5
2013Oct20133835.87-101454.9
2013Oct21134222.1-103623.3
2013Oct2213468.98-105742.3
         
2013Oct23134956.54-111851.6
2013Oct24135344.8-113950.7
2013Oct25135733.78-12039.3
2013Oct2614123.48-122117
2013Oct2714513.93-124143.3
         
2013Oct281495.14-13157.8
2013Oct29141257.12-13220.3
2013Oct30141649.88-134150.1
2013Oct31142043.43-14127.1
2013Nov1142437.78-142050.6
         
2013Nov2142832.93-14400.4
2013Nov3143228.9-145855.9
2013Nov4143625.69-151736.8
2013Nov5144023.29-15362.7
2013Nov6144421.72-155413.1
         
2013Nov7144820.96-16127.5
2013Nov8145221.03-162945.7
2013Nov9145621.92-16477.2
2013Nov1015023.63-17411.6
2013Nov1115426.17-172058.4
         
2013Nov1215829.54-173727.3
2013Nov13151233.74-175338
2013Nov14151638.77-18929.9
2013Nov15152044.63-18252.8
2013Nov16152451.33-184016.2
         
2013Nov17152858.86-18559.8
2013Nov1815337.23-19943.2
2013Nov19153716.42-192356.1
2013Nov20154126.45-193748
2013Nov21154537.29-195118.6
         
2013Nov22154948.96-20427.5
2013Nov2315541.43-201714.4
2013Nov24155814.71-202939
2013Nov2516228.77-204140.8
2013Nov2616643.61-205319.6
         
2013Nov27161059.21-21434.9
2013Nov28161515.56-211526.6
2013Nov29161932.64-212554.2
2013Nov30162350.42-213557.5
2013Dec116288.9-214536.2
         
2013Dec2163228.03-215449.8
2013Dec3163647.8-22338.3
2013Dec416418.18-22121.3
2013Dec5164529.14-221958.4
2013Dec6164950.64-222729.6
         
2013Dec7165412.67-223434.5
2013Dec8165835.18-224113
2013Dec917258.15-224724.7
2013Dec1017721.54-22539.6
2013Dec11171145.34-225827.3
         
2013Dec1217169.51-23317.8
2013Dec13172034.02-23740.9
2013Dec14172458.85-231136.5
2013Dec15172923.97-23154.3
2013Dec16173349.34-23184.4
         
2013Dec17173814.95-232036.5
2013Dec18174240.75-232240.6
2013Dec1917476.73-232416.6
2013Dec20175132.84-232524.5
2013Dec21175559.06-23264.1
         
2013Dec2218025.36-232615.5
2013Dec2318451.71-232558.7
2013Dec2418918.07-232513.5
2013Dec25181344.42-23240.2
2013Dec26181810.71-232218.6
         
2013Dec27182236.92-23208.8
2013Dec2818273.01-231730.8
2013Dec29183128.94-231424.8
2013Dec30183554.69-231050.8
2013Dec31184020.21-23649

04 March 2013

Comet PANSTARRS(C/2011 L4) is Here


Comet PANSTARRS (C/2011 L4) has given a good show in southern hemisphere and it’s now time for northern hemisphere to enjoy the show. On 5th March Comet will pass close to Earth at approx 1.1AU(1 AU = 149 597 871 km) and will reach perihelion(close to Sun in distance) on March 10th at a distance of .3AU(1 AU = 149 597 871 km).  PANSTARRS(C/2011 L4) should be a good challenging object from 6th of March from Bangalore and becomes easier to spot as days pass. The comet will stay low in the western horizon after sunset, the altitude of the comet PANSTARRS (C/2011 L4) will be 5degrees at 6:45pm on 5th march and on 12th of March the altitude will be 10degrees from the western horizon at 6:45pm. Due to the low altitude of the comet, it is better to plan the observation session in a place where there is no obstruction in the western horizon like trees or buildings. Here are few charts with the positions of the comet PANSTARRS (C/2011 L4) after sunset. The charts are from 5th to 12th of March with altitude of the comet at 6:45pm.


Chart of  5th March Comet PANSTARRS(C/2011 L4)  altitude will be close to 5degress at 6:45pm.  Sunset: 6:32pm. Comet PANSTARRS(C/2011 L4) sets at 7:10pm 
 

Chart of  6th March Comet PANSTARRS (C/2011 L4) altitude will be close to 6.5degress at 6:45pm.  Sunset: 6:32pm. Comet PANSTARRS(C/2011 L4) sets at 7:15pm.
 

Chart of  7th March Comet PANSTARRS(C/2011 L4)  altitude will be close to 8degress at 6:45pm.  Sunset: 6:32pm. Comet PANSTARRS(C/2011 L4) sets at 7:20pm
 

Chart of  8th March Comet PANSTARRS(C/2011 L4)  altitude will be close to 8.5degress at 6:45pm.  Sunset: 6:32pm. Comet PANSTARRS(C/2011 L4) sets at 7:23pm
 

Chart of  9th March Comet PANSTARRS(C/2011 L4)  altitude will be close to 9.5degress at 6:45pm.  Sunset: 6:32pm. Comet PANSTARRS(C/2011 L4) sets at 7:25pm

Chart of  10th March Comet PANSTARRS(C/2011 L4)  altitude will close to be 10degress at 6:45pm.  Sunset: 6:32pm. Comet PANSTARRS(C/2011 L4) sets at 7:28pm.
 

Chart of  11th March Comet PANSTARRS(C/2011 L4)  altitude will be close to 10.5degress at 6:45pm.  Sunset: 6:32pm. Comet PANSTARRS(C/2011 L4) sets at 7:30pm
 

Chart of  12th March Comet PANSTARRS(C/2011 L4)  altitude will be close to 10.6degress at 6:45pm.  Sunset: 6:32pm.Comet PANSTARRS(C/2011 L4) sets at 7:30pm