When you want to see the stars, find someplace dark
Sky events
The first meteor shower of 2015 is the annual Quadrantid meteor shower. The Quadrantids are a reliable shower, producing 60-120 ZHR, one to two meteors per minute. The Quadrantids are named for the obsolete constellation Quadrans Muralis, now part of the constellation Boötes.
Watching meteors requires no more equipment than your eyes and a dark sky, and can be enjoyable for just about anyone. Set the alarm early? Probably not this year.
Back on August 17th, Australian amateur astronomer Terry Lovejoy disocvered a very nice Christmas gift for us all to enjoy… A bright comet that we have now unwrapped and are able to enjoy through the new year.
Comet C/2014 Q2 Lovejoy is currently passing through perihelion. While closest to the Sun and the Earth it will be at its brightest during the first couple weeks of January. For northern hemisphere observers the comet is currently low in the southern sky and getting brighter each day.
The comet passes through perihelion on January 30th of 2015. For earthbound observers it will be at its brightest during the first weeks of January, reaching near 4th magnitude. It is currently visible around 5th magnitude in the faint constellation of Columba south of Orion. It has been visible without optical aid for a few weeks, as long as you have access to a dark sky and know where to look. As it brightens it will be easily visible, even rather obvious. With binoculars the view will be even better, a bright fuzzball with a wispy tail.
The next thing you may note about the orbital diagram is that the comet has a high inclination to the ecliptic. Currently approaching from underneath the plane of the solar system, the comet will exit north of our Sun. The practical side of this, is that over the next few weeks the comet will move northwards across the sky, rising higher each night. While our friends down south have been enjoying nice views of the comet approaching perihelion, it is northern hemisphere observers that will be able to best view the comet after perihelion.
One issue will be the bright Moon. Currently a waxing half phase, the Moon will be full on January 4th. This will make spotting the comet much more difficult and completely drown out the faint tail. By 9th or 10th the Moon will have waned enough to make comet viewing much more successful.
As January fades, so will comet C/2014 Q2. By the end of the month the comet will slip below unaided eye visibility, while staying within reach of binoculars through April or so. Sky watchers will be able to follow the comet for months betond that with the aid of a telescope. Enjoy the comet while you can, 8,000 years will pass before this comet returns to the inner solar system.
Taking the material I acquired last weekend, you can process a single frame, or process an animation. To bring out the tail a little better I converted the two hours of frames into an animated GIF. I also converted the frame to black and white and inverted it to show the fine detail.
The results are encouraging. Now… How well will this comet photograph when at its brightest in a couple weeks?
The first real product of Saturday’s imaging session on Mauna Kea. Processing comet images is a challenge (actually I am using far less correct language while I work on it). The problem is that comets move rapidly against the star field. This creates all sorts of issues when attempting to assemble a final image.
The single frame shown here is he product of 28 light frames and thirty calibration frames. The light frames used in this image were each 4 minutes long, accounting for nearly two hours of exposure total. There were a few more, but a few had to be discarded due to wind-shake of the telescope during the exposure.
The image below is processed to align on the comet as it moves against the background stars. During the two hours of exposures the comet moved appreciably. The stars are somewhat suppressed by using a sigma reject combine, but they are still there. Processing like this allows the details in the tail to be seen.
With a set of images running for two hours taken without interruption other things can be done. One possibility is that these images can be animated, leading to another interesting product… Up next!
This evening, Dec 22nd, will see a brilliant Venus paired with a very thin crescent Moon. Look for the pair to appear just 12° above the setting Sun. Venus will set at 18:50HST, about one hour after sunset. A 1.8% illuminated Moon will be a nice match for Venus shining brilliantly at -3.9 magnitude. Separation will be just under 6°.
Winter solstice occurs today at 13:03HST. Today the Sun will occupy the most southerly position in the sky of the year. The term solstice comes from the Latin terms Sol (the Sun) and sistere (to stand still). On this day the Sun seems to stand still as it stops moving southwards each day and begins move to the north. This is the first day of winter as marked by many cultures in the northern hemisphere. Alternately, this is the first day of summer for those folks in the southern hemisphere.
| 2014 Solstices and Equinoxes | ||||
|---|---|---|---|---|
| UT | HST | |||
| Perihelion | Jan 4 | 05:59UT | Jan 3 | 19:59HST |
| Vernal Equinox | Mar 20 | 16:57UT | Mar 20 | 06:57HST |
| Summer Solstice | Jun 21 | 10:52UT | Jun 21 | 00:52HST |
| Apehelion | Jul 3 | 22:59UT | Jul 3 | 12:59HST |
| Autumnal Equinox | Sep 23 | 02:30UT | Sep 22 | 16:30HST |
| Winter Solstice | Dec 21 | 23:03UT | Dec 21 | 13:03HST |
| Source: NASA Sky Calendar | ||||
Stayed up late tonight to check on a few things in the sky. Firstly the Geminid meteor shower, which is peaking nicely. At least 100ZHR and bright enough to be nicely visible, even against the light of a bright gibbous moon.
The second item I wanted to see was comet C/2014 Q2 Lovejoy, now climbing higher in the sky as it swings northwards. It is currently somewhat low in Puppis, but getting higher each night as it moves nearly due north against the constellations. Currently it is an easy binocular object at around 7th magnitude. A quick sweep with my 9×50’s picked it up without effort halfway between Adhara and Canopus.
It is forecast to reach around 5th magnitude over the next month. Peak magnitude should occur near the new year while the comet is in Lepus. We placed and quite bright, I will be arranging to get a few photos of this comet through the new year!
Tonight the Moon and Jupiter will be close. The Moon will rise first, followed by Jupiter rising about 22:19HST. The Moon will be about 78% illuminated and about 9° from the bright planet. Tomorrow night the Moon will have moved to the other side of Jupiter and be a bit closer, about 7° separation.
Today Mercury passes through superior conjunction, passing behind the Sun as seen from the Earth. The planet will appear in the sunset in ten days or so, reaching maximum elongation on January 14th.