Fig. 4, Sun imaged July 22, 14h 47m GMT (UT); 100mm refractor x45, 1/1000 sec ISO 200. Baader solar filter. John Vetterlein. Click the image for enlargement

Fig. 5, The large spot group imaged July 22, 14h 50m GMT (UT) 150mm OG x180, 1/2000 sec ISO 400. Baader solar filter. John Vetterlein. Click the image for enlargement

Fig. 2 The Sun imaged on  July 18 08h 12m GMT (UT): 100mm refractor x45, Baader filter 1/1000sec ISO100. John Vetterlein. Click the image for enlargement

Fig.3 The large sunspot group imaged 20 July 2003 at 10h 07m GMT (UT). 150mm O.G. x210 1/1000 sec. ISO 200, Baader solar filter. This group is now readily seen with the human eye using appropriate filter. John Vetterlein. Click the image for enlargement

Current solar activity

The Sun has had periods of a few days recently when no spots have been visible, as during the first week of July.

This is not particularly unusual in the present phase of the solar cycle.

Last September/October saw a particularly and uncharacteristic burst of activity which led to some spectacular aurora as well as the appearance of large sunspot groups.

Today (July 18) the solar disc is again showing a number of spots with one large group (just on the threshold of human eye visibility using filters) appearing on the eastern limb (Fig. 2).

Also visible, diametrically opposite on the western limb, is a large bright area. (There is the suggestion of a sunspot close to the western limb associated with this feature.)

These lighter patches are called faculae and are commonly associated with sunspots where the contrast makes them more readily discernible. (Fig.3) .

JV 18/07/04

Noctilucent Clouds

Observers are reminded (especially those of us in high northern latitudes) to look out for the noctilucent clouds (see archives) in the late "night" sky.

There was a fine display 25/26 June lasting a little under one hour either side of midnight.

JV 08/07/04

Venus in the morning sky, 2004

Fig 1: Venus 2004, July 06 11h 48m GMT. 175mm Maksutov telescope, f/15 prime focus image: 1/3000 sec. ISO 800. John Vetterlein.

Since inferior conjunction (transit) on 8th June, Venus will have separated from the Sun in the sky by some 30° in 23 days (July 1).

This is almost entirely due to the Sun's normal apparent forward motion (west to east) against the celestial sphere (star background) which in turn is a result of the motion of the Earth in its orbit about the Sun.

Venus, on the other hand, has been moving slowly westward against the star background.

Venus reaches a "stationary" point by the end of June and will then advance in Right Ascension (RA).

The diagram shows the path of Venus from April 30 to July 29 2004.

Dia 1 The path of Venus from 30 April to July 29, 2004.

The interesting thing about all this is that Venus has maintained a high declination and will continue to do so right through until mid-September, giving northern observers a splendid sighting of the planet in our morning skies.

Venus's rapid motion outward from the Sun will come to a halt when the planet reaches maximum western elongation on August 17th. Then the phase will be almost exactly 50 per cent.

Already Venus is bright enough to be seen in daylight. By the time it reaches maximum brightness in early to mid-July the planet will be relatively easy to spot in a clear, daytime sky. Those with the leisure and opportunity to test this out could follow Venus into daylight from an early observation shortly before sunrise.

Venus rises (Kirkwall) as follows ((Times are GMT - UT):

• July 1 1h 53m
• July 8 1h 33m
• July 16 1h 13m
• July 24 0h 55m
• July 31 0h 44m

JV 29/06/04