Blind Spot, something we are all familiar with and have experienced it one time or the other. With all the mirrors around in the car or truck there will be one area where we cannot see and we have to adapt and work around it. Sometimes its a matter of life and death. Something which we cannot observe even with mirrors, this got me thinking of astronomers and their mirrors, the telescope and blind spot ,that area where observation is not possible. Earth rotates on its axis every 24 hours and if a solar eclipse is happening in USA, we in India will be at the opposite side with nightfall, but at-least someone got to see the eclipse. But there are places in the sky where if some events happen nowhere on earth can we see or observe the event. This is the portion of the sky where the Sun is placed.
On a new moon day we cannot the see the moon, it's not that moon has vanished from the sky but its hidden in the glare of the Sun. When a celestial object is close to the Sun we call that object as, in conjunction with Sun. During new moon phase the moon is in conjunction with the Sun. This applies to planets too, planets Jupiter and Saturn were in conjunction with Sun in late January of this year and as you know by now, conjunction means close to the Sun. When planets are in conjunction with the Sun observations cannot happen and we have to wait for the planets to come out of Sun's glare. This can take from several days to months and during that time there is nothing that the earth bound astronomers can do but wait.
The dreaded wait, how many of you reading this article remember the wait for the emergence of COMET ISON in 2013. The COMET ISON was dubbed to be the comet of the century and was to be the brightest comet in the sky after its perihelion (close approach to Sun). The comet was observed and followed until it fell into the glare of the Sun, amateurs and professional astronomers waiting to see the reappearance never got the chance as the comet got disintegrated during its close approach to Sun. We had wonderful images before it went close to Sun, but as it got close to Sun all we could do was to wait for emergence as sun's glare hid the comet.
If we go back in time to 1994 and the event of great impact of comet Shoemaker Levy 9 on to the planet Jupiter, which proved Eugene Shoemaker's theory of the impacts by comets and asteroids on Planets are common, well in astronomical timeline of-course. The event took place in July and telescopes around the world were pointing at Jupiter and astronomers studied the event in great detail. At that time Jupiter was in the constellation of Virgo and the Sun was in the constellation of Gemini. Imagine if the same event would have taken place during conjunction of Jupiter with Sun, we would have missed the great event.
Its not only planets but stars and other celestial objects too that come close to the Sun in the sky during the year, reaching conjunction, and those objects also cannot be observed until they emerge out of the glare. For example ,in the month of February Sun is in the constellation of Capricornus and we cannot see the stars or the objects in the constellation due to the bright Sun.
In the month of January of 2020 the red star in Orion constellation, Betelgeuse, dimmed in brightness unexpectedly and astronomers were able to measure the brightness until it came back to its original brightness in April of 2020. This was a good opportunity to study the brightness variation of the star as Betelgeuse was well placed in the sky away from the bright Sun. The same event if it had happened in the month of June, you know where I am going with this, yes Betelgeuse will be in conjunction with Sun in June.
There are many such rare events that we could have missed if the event had taken place during conjunction with Sun, even the closest supernova in Large Magellanic Cloud which took place in 1987 if it had happened during conjunction.
Sun is a big blind spot for astronomers, even with their mirrors they will miss anything close to Sun. Astronomers take advantage of even the smallest window and try to learn everything they can, because they know that these are rare events. For astronomers there is no such thing as being at right time at right place, they have to make best of what they get.
Knowing this I am very sure that it will make us look at each event and night as a gift and accept it with a sense of gratitude.
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