Search found 4 matches

by SkyWatcher
Thu Dec 29, 2005 11:58 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: Earthrise
Replies: 27
Views: 8368

If the same side of Luna always faces the Earth; wouldn't the Earth always be in about the same area of sky as viewed from the Moon??? Then there wouldn't really be an Earth rise. Orin Yes, but Apollo 8 was not on the Moon but moving around the Moon. So the point of view was changing and they could...
by SkyWatcher
Fri Dec 02, 2005 11:36 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD of Nov 27, 2005: Light Echoes from V838 Mon
Replies: 6
Views: 2031

A previous APOD on light echos stated that it can appear to enlarge FASTER than the speed of light. If the matter was a perfect sphere centered on the pulsar, the echo would appear instantaniously - infinite speed. If the mater was a plane the speed would be initially infinite as the light intersec...
by SkyWatcher
Mon Nov 28, 2005 4:28 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD of Nov 27, 2005: Light Echoes from V838 Mon
Replies: 6
Views: 2031

In the link mentioned (Hubble site) it is said that "the stellar outburst in Jan 2002". The sequence of 4 pictures shown starts from May 20, 2002 until December 17, 2002. The picture in APOD is dated Feb 8, 2004. So it is 2 years later than the outburst. If the star is in the center of the...
by SkyWatcher
Sun Nov 27, 2005 10:40 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD of Nov 27, 2005: Light Echoes from V838 Mon
Replies: 6
Views: 2031

APOD of Nov 27, 2005: Light Echoes from V838 Mon

It is said that the echo"spans about 6 light years". But the flash of light occurred at the beginning of 2002. The picture shown has been taken on February 8, 2004 (written on Hubble site) that is to say after a little more than 2 years. Since (I suppose... :? ) the light echo travels at t...