Expert: Philip Stahl - 10/22/2008

Question
I live in San Marcos Texas. For the past few nights I've noticed this really bright object in the southwest sky. I know Venus is out now but I don't believe it's that. It seems to fade in and out of brightness and then just disappears, then comes back again. It's not a plane, has no blinking lights and it doesn't move from the same spot in the sky. I saw it tonight again at 8:15 PM central time. I stopped looking at it for about 5 min. and when we looked up it was gone. Please, if you can tell me what it is I would appreciate it. It's brighter than Jupiter.  

Answer
Hello,

Well I checked for the time and location you gave and it isn't Venus. In that direction and time it is most likely Jupiter (now at magnitude -2.2) which is also in close proximity to the +2.9 magnitude star, Albaldah in the constellation of Sagittarius.

So, it could be the tandem of these two are creating the illusion of a bright object seen in your SW sky.

What would be helpful is if there was a way you could provide an estimate of the object's brightness. IF it is separate from Jupiter and you recognize Jupiter independently from this entity - then you can use Jupiter's magnitude of minus 2.2 as a check. Therefore, IS the object the same brightness as Jupiter, or greater? And by how much?

For example, if you know Jupiter is at (-2.2) would you say this object is as much as -3, or -4.4 (the brightest that Venus gets in the evening sky).

Is it up to (-12), the full Moon's apparent magnitude?

I ask these questions because 25 years ago when living in Barbados, an excited observer phoned me and said he'd been seeing a "strange bright object" in the same position each night. As soon as he reliably provided the direction in the sky, it was easy to verify he'd been watching Venus. However, he couldn't believe a planet could be that bright. But at (-4.4) it was.

Sorry I can't be of more help, but without more information, especially on its relative brightness, it is difficult if not impossible to say what it is.