Sky tonight for this month

Wednesday, March 6, 2013

Comet (C/2011 L4) Panstarrs

Comet (C/2011 L4) Panstarrs

Comet C/2011 L4 (PANSTARRS), is a non-periodic comet discovered in June 2011, that is expected to be visible to the naked eye when it is near perihelion in March 2013. The comet was discovered using the Pan-STARRS telescope located near the summit of Haleakala, on the island of Maui in Hawaii.
Comet C/2011 L4 had an apparent magnitude of 19 when it was discovered in June 2011. By early May 2012, the comet had brightened to magnitude 13.5, and could be seen visually when using a large amateur telescope from a dark site. As of October 2012, the coma (expanding tenuous dust atmosphere) was estimated to be about 120 000 km in diameter. The comet was spotted without optical aid on 7 February 2013 at a magnitude of ~6.
 Comet PANSTARRS will pass closest to Earth on 5 March 2013 at a distance of 1.09 au. It will come to perihelion (closest approach to the Sun) on 10 March 2013. Original estimates predicted the comet would brighten to roughly apparent magnitude 0 (roughly the brightness of Alpha Centauri A or Vega). An estimate in October 2012 predicted the comet might brighten to magnitude -4 (roughly equivalent to Venus). In January 2013 there was a noticeable brightening slowdown that suggests the comet may only brighten to magnitude +1. During February the brightness curve show a further slowdown of Magnitude at perihelion around +2.5/+ 3.0.
Comet C/2011 L4 probably took millions of years to come from the Oort cloud. After leaving the planetary region of the Solar System, the post-perihelion orbital period is estimated to be about 110 000 years.


DateAltitude at 7:00 pm ISTAzimuth at 7:00 pm IST
expected Magnitude (estimated) taken from MPC*Comments
March 952600.5
March 1062620.5
March 1172640.5
March 1282670.6
March 138.52690.7Thin crescent moon will act as a guide to look for the Comet.It will be about 5 deg below the moon towards 7 o’clock position
March 1492720.9
March 15102741.1
March 16102771.3
March 17102791.5


* expected magnitude may vary drastically as the Comets are known to behave erratically as far as brightness is concerned.

Magnitude predictions and observation till Feb 20th


Best place to observe:
You should have clear western horizon with no light pollution.  If your skyline in that direction is cluttered with trees, buildings, hills, whatever, chances are they’ll block your view of the comet.

Tuesday, February 12, 2013

Sky this week 6 Feb - 19 Feb, 2013


Sky this week

February 2013

sixth and seventh Week

6 Feb - 19 Feb, 2013



February 08 Ganymede Shadow Transit
February 11 Io Shadow Transit
February 12 -5 mag Iridium flare from delhi at 19:45 IST
February 13 Io Shadow Transit
February 15 Ganymede Shadow Transit
February 15 Asteroid 2012DA14 passes within 27,000 kms of earth
February 16 -4 mag Iridium flare from delhi at 06:03 IST
February 17 -5 mag Iridium flare from delhi at 05:57 IST
February 17 -5 mag Iridium flare from delhi at 19:32 IST


Sun rise/set and Moon rise/set data

6 Feb 2013        07:06 18:04
7 Feb 2013        07:06 18:05
8 Feb 2013        07:05 18:06
9 Feb 2013        07:04 18:07
10 Feb 2013     07:03 18:08
11 Feb 2013     07:03 18:08
12 Feb 2013     07:02 18:09
13 Feb 2013     07:01 18:10
14 Feb 2013     07:00 18:11
15 Feb 2013     07:00 18:11
16 Feb 2013     06:59 18:12
17 Feb 2013     06:58 18:13
18 Feb 2013     06:57 18:14
19 Feb 2013     06:56 18:14
6 Feb 2013        03:13 14:02
7 Feb 2013        04:11 15:06
8 Feb 2013        05:06 16:11
9 Feb 2013        05:55 17:17
10 Feb 2013     06:40 18:21 New Moon at 1250
11 Feb 2013     07:21 19:23
12 Feb 2013     07:59 20:23
13 Feb 2013     08:36 21:21
14 Feb 2013     09:13 22:18
15 Feb 2013     09:50 23:13
16 Feb 2013     10:29 -          
17 Feb 2013     11:09 00:07
18 Feb 2013     11:53 01:00 First Quarter at 02:01
19 Feb 2013     12:39 01:51


This weeks HOT news - An asteroid slightly bigger than the size of India Gate will pass within the Geosynchronous satellite orbit

Imagine a space rock as big as the india gate (as far as the height if india gate in terms of size) passing within the geosynchronous orbit and going back to the deep abyss of space. It looks like a Science fiction story but it is for real!!! On 15th Feb, this is exactly going to happen. 2012 DA14, a recently discovered asteroid (like the one our student have been discovering since last 3 years in the AIASC campaigns) will pass within 34, 000 kms from the centre of the earth (make it 27, 000 kms from the ground!!) making it the one of the closest flybys for an asteroid of this size for earth.

2012 DA14 is a near-Earth asteroid with an estimated diameter of about 45 meters (148 ft) and an estimated mass of about 130,000 metric tons.  It was discovered on February 23, 2012, by the OAM Observatory, La Sagra in Spain

The Asteroid 2012 DA14 will pass below distance where many commercial satellites are orbiting. It will pass inside the geosynchronous satellite ring, located about 35,800 km above the equator. The nominal pass will be 0.00023 AU (34,000 km; 21,000 miles) from the center of the Earth.

It is expected that the asteroid will travel rapidly from the southern evening sky into the northern morning sky on February 15, 2013. About 4 minutes after its Earth close approach, there is a good chance it will pass into the Earth’s shadow for about 18 minutes or so before reappearing from the eclipse. When traveling rapidly into the northern morning sky, 2012 DA14 will quickly fade in brightness.

With such a close approach to Earth, our planet’s gravity will change its future path and rise a chance of future impact.   There is an estimated cumulative 0.033% risk (1 in 3,030) of 2012 DA14 impacting Earth sometime between 2026 and 2069. Some scientist believe that similar-in-size object hit Tunguska in 1918. If it were to strike the Earth, it is estimated that it would produce the equivalent of 2.4 megatons of TNT. The Tunguska event has been estimated at 3−20 megatons. Observing 2012 DA14 will provide a good test as we anticipate the 2029 flyby of Apophis, a bigger asteroid (around 270 meters) that is expected to have a very close encounter too, at around 36,000 kilometers.


Asteroid 2012 DA14 will pass by Earth at distance of about 27,000 km (17,000 mile) from the Earth. Just for comparison – 400-meters wide asteroid YU 55  passed 320,000 kilometers (200,000 miles) from Earth on November 8, 2011. Even closer flyby of asteroid 2011 MD last June was closer than DA14 will at a distance of only 12,070 km (7,500 miles). But one thing is almost certain – it will surely miss us! For now, the orbit of 2012 DA14 is such that it will not crash into Earth for the foreseeable future

The 2013 close approach to Earth will reduce the orbital period of 2012 DA14 from 368 days to 317 days. The next notable close approach to Earth will be on 16 February 2046 when the asteroid will pass no closer than 0.0004 AU (60,000 km; 37,000 mi) from the center-point of Earth. Check out the SPACE calender at www.space-india.org to know the exact details.

For Iridium flare also check out the SPACE Calender at www.space-india.org There are no ISS passe sin the night for the week.



Constellation of the Week:

Auriga is one of the 48 constellations listed by the Ptolemy and remains one of the 88 modern constellations. Located north of the celestial equator, its name is the Latin word for "charioteer", associating it with various mythological charioteers. Auriga is most prominent during winter evenings in the Northern Hemisphere, along with the five other constellations that have stars in the Winter Hexagon asterism. Because of its northern declination, Auriga is only visible as far as 34° south; for observers farther south it lies partially or fully below the horizon. A large constellation, with an area of 657 square degrees, it is half the size of the largest constellation, Hydra.

Its brightest star, Capella, is an unusual multiple star system among the brightest stars in the night sky. In ancient Hindu astronomy, Capella represented the heart of Brahma. Beta Aurigae is an interesting variable star in the constellation.

Epsilon Aurigae, a nearby eclipsing binary with an unusually long period, has been studied intensively. Because of its position near the winter Milky Way.The most prominent variable star in Auriga is Epsilon Aurigae is an eclipsing binary with an unusually long period of 27 years; its last minima occurred from 1982–1984 and 2009–2011.The distance to the system is disputed, variously cited as 4600 and 2170 light-years.The primary is a white supergiant, and the secondary may be itself a binary star within a large dusty disk. Its maximum magnitude is 3.0, but it stays at a minimum magnitude of 3.8 for around a year; its most recent eclipse began in 2009. The primary has an absolute magnitude of −8.5 and an unusually high luminosity of 200,000 L, the reason it appears so bright at such a great distance. Epsilon Aurigae is the longest-period eclipsing binary currently known. The first observed eclipse of Epsilon Aurigae occurred in 1821, though its variable status was not confirmed until the eclipse of 1847–1848. From that time forward, many theories were put forth as to the nature of the eclipsing component. Epsilon Aurigae also has a non eclipsing component, which is visible as a 14th magnitude companion separated from the primary by 28.6 arcseconds. It was discovered by Sherburne Wesley Burnham in 1891.

Deep sky objects of the week:

Auriga has many bright open clusters in its borders, including M36, M37, and M38, popular targets for amateur astronomers. In addition, it has one prominent nebula, the Flaming Star Nebula, associated with the variable star AE Aurigae.



M36: Open Cluster M36 (also known as Messier Object 36, Messier 36, M36, or NGC 1960) is an open cluster in the Auriga constellation. It was discovered by Giovanni Batista Hodierna before 1654. M36 is at a distance of about 4,100 light years away from Earth and is about 14 light years across. There are at least sixty members in the cluster. The cluster is very similar to the Pleiades cluster (M45), and if it were the same distance from Earth it would be of similar magnitude.

M37: Messier 37 (also known as M37 or NGC 2099) is the richest open cluster in the constellation Auriga. It is the brightest of three open clusters in Auriga and was discovered by the Italian astronomer Giovanni Battista Hodierna before 1654. M37 was missed by French astronomer Guillaume Le Gentil when he rediscovered M36 and M38 in 1749. French astronomer Charles Messier independently rediscovered M37 in September of 1764 but all three clusters were recorded by Hodierna.

M38: Messier 38 (also known as M38 or NGC 1912) is an open cluster in the Auriga constellation.
It was discovered by Giovanni Batista Hodierna before 1654 and independently found by Le Gentil in 1749. M36 and M37, also discovered by Hodierna, are grouped together with M38 at a distance of about 3,420 light years away from Earth. The cluster's brightest stars form a pattern resembling the Greek letter Pi or, according to Webb, an "oblique cross." At its distance of 4,200 light years, its angular diameter of about 20' corresponds to about 25 light years, similar to that of its more distant neighbor M37.

Flaming star nebula: IC 405 (also known as the Flaming Star Nebula, SH 2-229, or Caldwell 31) is an emission/reflection nebula[1] in the constellation Auriga, surrounding the bluish star AE Aurigae. It surrounds the irregular variable star AE Aurigae and is located near the emission nebula IC 410, the open clusters M38 and M36, and the naked-eye K-class star Hassaleh. The nebula measures approximately 37.0' x 19.0', and lies about 1,500 light-years away.


Sky at night at 8:00 pm on 20th Feb, 2013

Written by Sachin Bahmba and C B Devgun

Wednesday, January 30, 2013

Sky this week 30 jan - 5 Feb, 2013


Sky this week

January - February 2013

Fifth Week

30 jan - 5 Feb, 2013


January 31 -2.8 mag ISS pass over Delhi
January 31 GISC and GAN starts phase II
February 02 Europa shadow transit
February 02 -2.6 mag ISS pass over Delhi
February 02 -2.0 mag iridium flare from delhi
February 03 -2.4 mag ISS pass over Delhi
February 03 Last quarter Moon
February 04 Mars and Neptune within 0.5 degrees
February 04 Io shadow transit
February 04 -5.0 mag iridium flare from delhi

ISS PASS details

Date   Mag   Max height Alt Az
31 Jan -2.8   06:21:19   57° NE
02 Feb -2.6   06:16:52   36° SW
03 Feb -2.4   05:27:19   46° SE

ISS passes make this week a special week as now bright (more than -2 mag) passes of ISS start to appear in the delhi skies. It becomes more special as the ISS EarthKam mission has just ended on February 1 and so many SPACE associated schools and units have gathered images taken by camera onboard the ISS. Now its time to look up and see the ISS with the naked eyes. basic info has been given in this writeup, for more details go to http://space-india.org/space_calendar.html

Jovian events  - one can see the transit of shadow of the jovian satellites on the disk of jupiter with a moderate sized telescope.

Iridium flares - we have given the details for the bright iridium flares which can be seen with naked eyes from delhi. The brightness may vary as it depends upon where the observer is located with respect to the satellite. So it can be more or less for an observer.

Sunrise/Sunset and Moonrise/Moonset for the week

Sun
30 Jan 2013 07:10 17:59
31 Jan 2013 07:10 18:00
01 Feb 2013 07:09 18:00
02 Feb 2013 07:09 18:01
03 Feb 2013 07:08 18:02
04 Feb 2013 07:08 18:03
05 Feb 2013 07:07 18:04

Moon
30 Jan 2013 21:06 08:44
31 Jan 2013 22:04 09:20
1 Feb 2013 23:04 09:57
2 Feb 2013 10:37
3 Feb 2013 00:05 11:20
4 Feb 2013 01:08 12:09
5 Feb 2013 02:11 13:03



Constellation of the week

This week again we will be seeing Taurus (the Bull or the Vrishabha in hindi) crossing the meridian at 8:00 pm. Its a V shaped constellation to the folks living in big cities but it stands out in the dark skies with lot more stars.

Taurus is one of the constellations of the zodiac, which means it is crossed by the plane of the ecliptic. Its name is a Latin word meaning "bull",. Taurus is a large and prominent constellation in the northern hemisphere's winter sky. It is one of the oldest constellations, dating back to at least the Early Bronze Age when it marked the location of the Sun during the spring equinox. Taurus came to symbolize the bull in the mythologies of India, Ancient Babylon, Egypt and Greece.
There are a number of features of interest to astronomers. Taurus hosts two of the nearest open clusters to Earth, the Pleiades and the Hyades, both of which are visible to the naked eye. At first magnitude, the red giant Aldebaran is the brightest star in the constellation. In the northwest part of Taurus is the supernova remnant Messier 1, more commonly known as the Crab Nebula. One of the closest regions of active star location, the Taurus-Auriga complex, crosses into the northern part of the constellation. The variable star T Tauri is the prototype of a class of pre-main-sequence stars.


Deep Sky Object of the week

Pleiades cluster (M45)
At 8:00 pm look just above your head, if the skies are clear and no haze is there, you should see a group of stars clustered together. You may be able to see 4-6 stars in a clump depending on how good your eyesight is!! Well this is not a constellation but what we call an open cluster of stars, or a nakshatra called Krittika in hindu astronomy.

In Hindu mythology, the god Murugan(Skanda/Subrahmanya/Kartikeya) was raised by the six sisters known as the Krittikā and thus came to be known as Kārtikeya. According to the Mahābhārata, Murugan was born to Agni and Svāhā, after the latter impersonated six of the seven wives of the Saptarishi and made love to him. The Saptarshi, hearing of this incident and doubting their wives' chastity, divorced them. These wives then became the Krittikā.(Taken from Wikipedia)

For astronomers, pleiades or krittika offers so much to study. In astronomy, the Pleiades, or Seven Sisters (Messier object 45 or M45), is an open star cluster containing middle-aged stars located in the constellation of Taurus. It is among the nearest star clusters to Earth and is the cluster most obvious to the naked eye in the night sky. The name Pleiades comes from Greek mythology.

Its a treat to watch pleiades through any of the optical instruments. Binoculars do justice to the size of the cluster showing all the stars packed tightly, with a telescope you will have to move it a bit to see the whole extent of the cluster.

To get access to info about telescopes and other astronomy equipment just login to www.spacearcade.in


Sky at 8:00 pm on 30th January, 2013


 Written by Sachin bahmba and C B Devgun