Markarian 177 and companion (recoiling Black Hole or wierd LBV/Supernova)

[Steve Gottlieb]

This past new moon weekend Howard Banich and I observed with Jimi and his rather large toy (48-inch f/4). Here's the first of several objects that I'll report on --

Markarian 177 and SDSS J113323.97+550415.8
11 33 23.5 +55 04 20
Size: 0.35'x0.3'
Mag: 15.5V (main galaxy), ~17V (blue knot)

Mrk (Markarian) 177 is a relatively nearby dwarf galaxy with an AGN (active galactic nucleus) and a very unusual blue object at the southeast end. This enigmatic "star" exhibits broad emission lines and strong variability. It is possibly a luminous blue variable star (LBV) that has been erupting for decades since 1950, followed by a Type IIn supernova in 2001. If that's the case, the multidecade LBV eruptions are the longest ever observed. It has also been speculated that Mrk 177 once contained a double black hole, and the blue object is a massive black hole that was ejected from the nucleus of Mrk 177!

The full story (though not the final say!) is contained in the 2014 paper: "SDSS1133: an unusually persistent transient in a nearby dwarf galaxy"

A summary of this bizarre object is in the Sky & Tel story "Evicted Black Hole or Weird Supernova?"

Whatever it is, we weren't sure what to expect or even if it was a visual object. At 610x, Mrk 177 appeared fairly faint, small, round, 12" diameter, moderate surface brightness, gradually brightens to the center but no zones. SDSS J113323.97+550415.8 was visible as an extremely faint "star" at the southeast end [just 6" from center] of the galaxy. In addition 2MASX J11331883+5504515 = PGC 3473037 lies 52" NW. This galaxy is very faint, very small, slightly elongated, ~10" diameter.

Mrk 177.jpg

[Jimi Lowrey]

Its not very often that you get to see a astronomical object that is not know what it is. Like Steve said we were not sure what to expect and I was surprised and excited to catch this unusual object. Our visual observation might be a first for this object? Its hard to tell if someone has seen something before. I encourage other to "Give it a GO!" This is one UNUSUAL object.

[Steve Gottlieb]

Considering Markarian 177 is a pretty obscure object in the first place and that the enigmatic blue object is currently in a "bright" stage at 17V (or fainter), I'd say the odds are pretty good it was a visual first.

[Howard B]

...and here's my sketch:

Markarian177_crop.jpg Markarian177_crop_invert.jpg

We were using 610x and the "LBV" object was an averted vision object that came and went. Really cool!