The "main event" of this year’s astronomical phenomena—Comet C/2012 S1 (ISON)—will make its grand appearance at the end of the month!
First, here is the data from scully.cfa.harvard.edu:
Date TT R. A. (2000) Decl. Delta r Elong. Phase m1 m2 2013 11 24 14 45 42.7 -18 53 56 0.8693 0.3002 17.1 104.3 3.0 2013 11 25 15 01 27.3 -20 05 10 0.8819 0.2551 14.3 107.0 2.5 2013 11 26 15 18 04.6 -21 09 58 0.8998 0.2058 11.4 109.3 1.8 2013 11 27 15 35 58.3 -22 05 30 0.9244 0.1502 8.2 110.4 0.7 2013 11 28 15 56 28.2 -22 43 29 0.9594 0.0826 4.6 106.9 -1.3 2013 11 29 16 23 17.5 -19 52 57 0.9762 0.0322 1.8 107.7 -4.5 2013 11 30 16 21 22.4 -16 20 32 0.9125 0.1145 5.3 127.4 -0.2 2013 12 01 16 19 11.8 -13 59 07 0.8681 0.1757 8.1 128.1 1.2 2013 12 02 16 17 23.9 -11 56 02 0.8309 0.2281 10.6 127.3 2.0 2013 12 03 16 15 54.3 -10 00 54 0.7980 0.2754 13.0 126.1 2.5
The brightness of this comet has been gradually increasing as predicted, and it is estimated to reach its peak on November 29, reaching a magnitude of -4.5! What does this mean? The brightest star is only magnitude -1.47, and Venus can reach magnitude -4.89 at its brightest (the smaller the number, the brighter the object). Thus, it seems the maximum brightness of C/2012 S1 (ISON) is similar to that of Venus at its peak. The difference is that no matter how bright Venus is, it only looks like a point, whereas a comet, also known as a "broom star," allows us to see a beautiful cometary tail! It may also display other brilliant colors. Such a comet is very rare to encounter—perhaps even rarer than a total solar eclipse. At night, taking a pair of binoculars and sitting comfortably on a rooftop to watch this beautiful "Celestial Comet" is an incomparable enjoyment.
I checked the calendar, and the 29th is the 27th day of the lunar month, which falls in the last ten days of the lunar cycle, so there will be no moonlight interference. Why do I want to go home? Because my home is in the countryside, where light pollution is very low, and many stars can be seen with the naked eye, let alone this great comet. Furthermore, my telescope and other equipment are all at home, so going home to observe is the best choice. Besides, I am also a bit homesick~ ^_^
As for the weather, I expect it will be fine. Autumn and winter in Guangdong are relatively sunny, and it is the same where I live. Even if the weather turns bad, such a spectacle is worth waiting for. Even if it fails to reach the expected magnitude of -4.5, I still think it is necessary to observe it (a year ago, it was predicted to reach magnitude -13, which means it would be brighter than the moon! Of course, that seems impossible now, but it is still quite ideal). After all, if you try, you might not succeed; but if you don’t try, you definitely won’t.
I am aware that reality is not as perfect as the imagination. The extreme brightness mentioned above occurs during perihelion, when the comet is very close to the Sun and essentially unobservable (it rises and sets almost simultaneously with the Sun). Therefore, in my personal opinion, the best time to observe this comet is about four or five days before its peak (around the 24th), between 5:50 AM and 6:20 AM. (It cannot be too early, because it hasn’t risen yet or its altitude is too low, causing its brightness to be heavily dimmed by atmospheric extinction; and it cannot be too late, as the Sun’s influence becomes too great). During this period, its magnitude will be around 3–4 (after considering atmospheric extinction). Using binoculars or an astronomical telescope, I expect the observation results will still be quite good!
During that time, Mercury and Saturn will also be near C/2012 S1 (ISON). Among these three, Mercury will be the brightest. If you are lucky, you might even catch a glimpse of Mercury (though there might not be enough time~).
Regardless, I am looking forward to it and have prepared myself to wake up early for several consecutive days... To use a popular phrase, "University needs a trip taken on a whim." I think the pursuit of astronomy is that spontaneous journey in my heart. I am willing to wait for it, even if there is only a small possibility, because I understand that astronomy is essentially a series of vigils of love ^_^
Here are some images found on the Mufuu Forum:
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