The Planets in 2007

Dia.1: Looking west at 17h 40m UT on February 1st. 2007.

Dia.2: A diagrammatic wide field view of the sky from SE to SWW on the morning of 12 January 2007, time  07h 30m UT.

Fig. 1: The constellation of Leo with Saturn to the right of Regulus. A 20 sec. exposure with a static camera, 26mm f/2.8, ISO 500.

Fig. 2: Criss-cross - Cables and Trails. Dawn sky (08h 20m UT) over Brinsworth near Rotherham, Yorkshire. The sky would have been clear but for the aircraft condensation trails. Photograph: Ann Chapman.

Inferior Planets: Venus is now visible low in the SSW shortly after sunset setting at 17h 24m UT on January 12, and at 18h 44m UT on the 31st.

Mercury should also be visible from the second half of January into the first week of February. Dia. 1 shows the position of the two planets in the early evening sky on February 6th.

Superior Planets: From northern latitudes Jupiter is out of the picture for all practical purposes, telescopically at least. Saturn also is on the decline both in terms of its declination, and therefore altitude, as well as in the disposition of the ring system.

As mentioned in a previous edition of these notes, Mars will be at opposition on Christmas Eve this year when it will also be occulted from these latitudes by the close to full Moon, a rare event indeed.

Returning to Jupiter and Saturn. I have made the point many times that although the bright, red star Antares is regarded as a summer star (it culminates close to midnight on June 2nd), for observers in high northern latitudes January is an opportune time to see it in the morning sky. Use the brilliant Jupiter as a guide (Dia. 2) To my eyes, at least, Antares is the most red in colour of the brighter stars.

Saturn is still north of the celestial equator and will come to opposition on February 10th this year. I have already drawn attention to nearby Regulus in the previous article. (See Dia. 2 and Fig. 1.)

Saturn will spend all of 2007 and 2008 in Leo, which helps to emphasize the scale of this constellation, the 12th in size in the entire sky. (Compare this to Orion which is 26th in the league table of sizes. Hydra is the largest constellation in the entire sky followed by Virgo which makes it, therefore, the largest Zodiacal constellation.)

Saturn will have completed three retrograde loops in Leo before it eventually passes into Virgo between 2- 3 September 2009. That will signify an important date for me since when I first became seriously interested in astronomy Saturn was in Virgo. My schoolboy diary of the period reads: 1951 May 4. Identified Saturn for the first time. Observed with 30x65mm Watson telescope, the rings appearing magically unreal!

Saturn’s sidereal period being a little over 29 years, I am unlikely in my lifetime ever again to see the planet to advantage from these latitudes. A salutary reminder of one’s mortality. But by then, no doubt, aircraft condensation trails will have wiped out the sky for many of us! (Fig. 2.)

JV 10/01/07