[Zebooka]

How long (approx.) shutter can be opened when using bulb exposure on Pentax Super Program / Super A camera?

I know, it's until batteries aren't empty. But how long it is?

(Considering this cam as a film body)

[Wheatfield]

I don't recall exactly, but a few hours with fresh batteries comes to mind.
If you really want a body that is good for bulb exposure, look for a manual mechanical one such as a K1000.

[Zebooka]

K1000 is definitely not my choice.

I liked Super A / Super Program because of P,Av,Tv,M,X,B modes
It also gives an ability to use modern digital lenses in P / Tv modes.

I will use this cam as a replacement of Zenit 12xps. I'm wondering of bulb, because I want to shoot few night-sky shots this summer. But it will be not primary subject.

The other camera that satisfies my demand of features is LX. But it's too expensive for me right now, and hard to find.

[titrisol]

it should be a few hours at least

[Pentaxie]

With fresh batteries, a couple of hours; exatcly how long, I dunno.
With my mechanical Vivitar 3000N, I can leave it for days.
I remember taking astro-photography, and I left it open for like almost 1 day long

[Wheatfield]

K1000 is definitely not my choice.

I liked Super A / Super Program because of P,Av,Tv,M,X,B modes
It also gives an ability to use modern digital lenses in P / Tv modes.

I will use this cam as a replacement of Zenit 12xps. I'm wondering of bulb, because I want to shoot few night-sky shots this summer. But it will be not primary subject.

The other camera that satisfies my demand of features is LX. But it's too expensive for me right now, and hard to find.

Your choice, from what you posted, was a camera that would do long exposures on bulb.
From the info you gave in your initial post, the K1000 is a better choice.
Battery operated cameras aren't as reliable for this purpose.
With your follow up information (it would be nice to get this stuff all at once rather than having it dribbled out), the Super Program is as good as anything else that has the same or similar feature set.
I find it interesting that the LX, which is an AE auto or manual camera only has an acceptable feature set when what you seem to want is the full exposure mode set of the Super Program.

[titrisol]

Agree with Wheatfield, but aldo the MEsuper/Me/Mx can do very long exposures and do not suck up the battery

[Zebooka]

Then I suppose I'll stay with my Zenit 12xps
(until LX).

Better to find perfect super-wide-angle lens. Something like flectogon