{"id":6816,"date":"2011-12-07T01:00:39","date_gmt":"2011-12-07T11:00:39","guid":{"rendered":"http:\/\/darkerview.com\/wordpress\/?p=6816"},"modified":"2012-12-31T16:24:58","modified_gmt":"2013-01-01T02:24:58","slug":"a-daytime-comet","status":"publish","type":"post","link":"https:\/\/darkerview.com\/wordpress\/?p=6816","title":{"rendered":"A Daytime Comet?"},"content":{"rendered":"

The rumor is running around the various astronomy sites and listservers that Comet C\/2011 W3 Lovejoy might be daytime visible. Will it be? That is a very qualified maybe.<\/p>\n

\"C2006\/P1<\/a>
C2006\/P1 McNaught photographed five degrees from the Sun, stack of three images<\/figcaption><\/figure>This sun-grazer comet was discovered just a few days ago, on November 27th, by Australian amateur astronomer Terry Lovejoy<\/a>. The comet is a member of the Kreutz comet family<\/a>, and like other members of the family it will approach the Sun quite closely, about 548,000 miles (882,000 km) from the Sun. Of course those distances are solar centric distances. Taking the radius of the Sun into account means that the comet will be a mere 115,000 miles (186,000 km) above the photosphere, hot indeed!<\/p>\n

It becomes a valid question to ask if comet Lovejoy will even survive perihelion transit.<\/p>\n

Passing that close to the Sun will mean that the volatile elements of the comet will be streaming off the comet at a fantastic rate, enough to dramatically brighten the comet. Below you will find the ephemeris for perihelion on Dec 16th (Dec 15th HST) from the Minor Planet Center<\/a>. As you can note, the predicted magnitude is -8! This is bright enough to be seen in broad daylight. Thus the possibility of a daytime comet.<\/p>\n

The catch is that the comet will be quite close to the Sun. Within 2\u00b0 as the Sun and comet rise on the morning of the 15th here in Hawai’i. For observers in the islands the best chance to look is on the morning of the 15th, as perihelion will occur in the afternoon as the comet passed behind the Sun from our point of view.<\/p>\n

Will it be visible? Maybe. It depends on the accuracy of the magnitude estimates, which are uncertain to say the least. It could be substantially dimmer, or even substantially brighter than forecast under such conditions. The proximity to the Sun also complicates the issue. It is worth a look, seeing a daytime comet is highly unusual.<\/p>\n

If you do look please take a few simple precautions… Do NOT use any sort of optical aid this close to the Sun, the risk of permanent eye damage is too great. If it is bright enough the comet should be a naked eye object. It will greatly help to position yourself to put the Sun just behind some obstruction. A building, a streetlight, anything to block the Sun’s glare and aid in picking out the comet. On the morning of the 15th the comet will rise 2\u00b0 behind the Sun, thus 2\u00b0 lower in the sky.<\/p>\n

Give it a try!<\/p>\n

\n
Date    TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase   m1    m2\r\n2011 12 05    15 16 55.0 -49 16 23   0.7020  0.5385    31.9   104.4  10.5  16.7
2011 12 06    15 35 50.9 -47 54 07   0.7082  0.5050    29.3   107.4  10.3  16.8
2011 12 07    15 53 36.9 -46 18 58   0.7170  0.4704    26.6   110.4  10.0  16.8
2011 12 08    16 10 07.0 -44 32 30   0.7285  0.4344    23.9   113.4   9.7  16.9
2011 12 09    16 25 18.7 -42 36 14   0.7429  0.3970    21.2   116.2   9.3  16.9
2011 12 10    16 39 12.4 -40 31 31   0.7604  0.3576    18.5   119.0   8.9  16.9
2011 12 11    16 51 50.3 -38 19 18   0.7813  0.3161    15.9   121.7   8.5  16.9
2011 12 12    17 03 15.7 -35 59 57   0.8060  0.2716    13.2   124.2   7.9  16.9
2011 12 13    17 13 31.2 -33 32 42   0.8352  0.2233    10.5   126.5   7.1  16.7
2011 12 14    17 22 37.5 -30 54 29   0.8705  0.1691     7.7   128.3   6.0  16.4
2011 12 15    17 30 26.9 -27 55 51   0.9153  0.1048     4.8   128.7   4.0  15.5
2011 12 16    17 31 43.4 -23 03 22   0.9885  0.0057     0.2    42.0  -8.5   5.4
2011 12 17    17 17 12.6 -25 07 18   0.9135  0.1046     4.7   130.1   4.0  15.6
2011 12 18    17 11 57.9 -27 12 24   0.8656  0.1692     7.5   130.6   6.0  16.6
2011 12 19    17 08 21.5 -29 13 16   0.8260  0.2234    10.1   129.7   7.1  17.0
2011 12 20    17 05 34.5 -31 14 08   0.7912  0.2717    12.5   128.6   7.8  17.2
2011 12 21    17 03 19.7 -33 17 03   0.7597  0.3162    14.8   127.2   8.4  17.3<\/pre>\n<\/blockquote>\n","protected":false},"excerpt":{"rendered":"
The rumor is running around the various astronomy sites and listservers that Comet C\/2011 W3 Lovejoy might be daytime visible. Will it be? That is a very qualified maybe. This sun-grazer comet was discovered just a few days ago, on November 27th, by Australian amateur astronomer Terry Lovejoy. The comet is a member of the … Continue reading “A Daytime Comet?”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[15],"tags":[700,337,264,699],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/darkerview.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/6816"}],"collection":[{"href":"https:\/\/darkerview.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/darkerview.com\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/darkerview.com\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/darkerview.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6816"}],"version-history":[{"count":0,"href":"https:\/\/darkerview.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/6816\/revisions"}],"wp:attachment":[{"href":"https:\/\/darkerview.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6816"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/darkerview.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6816"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/darkerview.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6816"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}