Starship Asterisk*

astraburning62 wrote: ↑Wed Aug 04, 2021 5:38 am I get really tired of descriptions of intergalactic objects such as Centaurus A (which is 13.05million light years away) as being 'nearby'. 13 million lights is not in any human sense of the word, 'nearby'. Sure, in a galactic relativistic sense its closer than most but use of this kind of relativistic language is far from helpful in communicating just how vast interstellar distances actually are. It still stuns me that highly educated intelligent people still have a warped understanding of how truly vast the universe - to me its the flat earth mentality of the era we inhabit. We need to start communicating better the cosmic realities and not cushion people from them. Having said that, very interesting picture, thanks for posting APOD Robot.

shaileshs wrote: ↑Wed Aug 04, 2021 4:34 am At least to me (to a naked eye, without zoom), comparing center of "right top" zoomed into "right middle" - I'm a bit challenged to see how they are same.. ?

astraburning62 wrote: ↑Wed Aug 04, 2021 5:38 am I get really tired of descriptions of intergalactic objects such as Centaurus A (which is 13.05million light years away) as being 'nearby'.

Chris Peterson wrote: ↑Wed Aug 04, 2021 12:58 pm

astraburning62 wrote: ↑Wed Aug 04, 2021 5:38 am
I get really tired of descriptions of intergalactic objects such as Centaurus A (which is 13.05million light years away) as being 'nearby'.

Because it is. This is an astronomical site, and on an astronomical scale this distance is nearby. And it's important that the descriptions continue to emphasize that point.

astrocat wrote: ↑Wed Aug 04, 2021 11:39 am looks like the 165000 light years in the top left corner is wrong, as scale for the double-ended arrow; should probably be a few light days or so maybe;

bystander wrote: ↑Wed Aug 04, 2021 2:15 pm viewtopic.php?t=41817

johnnydeep wrote: ↑Wed Aug 04, 2021 4:18 pm
I can't seem to find an explanation for the almost symmetrical huge purple "smoke", aka "jets in the largest scale image. I also find it odd that it's angle doesn't seem to align with either the central jet or the galactic dust disk.

• There is an apparent slow precession of Centaurus A's accretion disk
  (unrelated to its more distant dust disk)
  resulting in a spiral structure to its distant jet lobes.

https://www.aanda.org/articles/aa/pdf/2015/08/aa26797-15.pdf wrote:
A&A 580, L8 (2015) DOI: 10.1051/0004-6361/201526797
c©ESO 2015 : Astronomy&Astrophysics

• Planck revealed bulk motion of Centaurus A lobes
  F. De Paolis1 et al.

Overview over the ~8°radio structure of Centaurus A.

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<<The elliptical (S0) galaxy NGC 5128 is an example of the family of ellipticals that have an absorbing band of gas and dust projected across the stellar body. The center of this system harbors a supermassive black hole with mass about 10⁷−10⁸ M (see, e.g., Silge et al. 2005; Marconi et al. 2006; Neumayer 2010), which powers two jets, two inner lobes (with size about a few arcmin each), and the two outer giant lobes. The GLN and the northern jet are likely tilted toward the observer and the GLN is thought to be closer to us than the GLS. Indeed, the jets appear clearly in the radio band and are obviously shooting out of Centaurus A, with the radio emission becoming more diffuse at greater distances from the center of the galaxy (Neff et al. 2015). The jets consist of a plasma state, i.e., a high-temperature stream of matter. The jets are also clearly observed in X-rays (see, e.g., Karovska et al. 2002, and references therein). The most prominent feature is the jet extending for about 8 kpc toward the northeast (upper left in the sky), while a less prominent jet extends toward the southwest. The apparent brightness difference between the jets and the proper motion asymmetries of both the jets and the inner lobes (Tingay et al. 2001) are thought to be due to the viewing geometry: the first jet is moving toward us, while the second is moving away (see, e.g., Burns et al. 1983; Israel 1998). This was also suggested by the Faraday depolarization analysis of the southern inner lobe (Clarke et al. 1992).>>

johnnydeep wrote: ↑Wed Aug 04, 2021 4:18 pm I can't seem to find an explanation for the almost symmetrical huge purple "smoke", aka "jets in the largest scale image. I also find it odd that it's angle doesn't seem to align with either the central jet or the galactic dust disk.

VictorBorun wrote: ↑Wed Aug 04, 2021 4:46 pm
is not it strange for a giant elliptical galaxy like Centaurus A to have a dusty disk full of young giant stars, too?

A pair of jets is somewhat more typical. M87 has those too.

bystander wrote: ↑Wed Aug 04, 2021 5:08 pm

johnnydeep wrote: ↑Wed Aug 04, 2021 4:18 pm I can't seem to find an explanation for the almost symmetrical huge purple "smoke", aka "jets in the largest scale image. I also find it odd that it's angle doesn't seem to align with either the central jet or the galactic dust disk.

I found the original image, the original CSIRO article on phys.org and a scientific article based on the data. Here is an article on associated gamma-rays from Fermi.

VictorBorun wrote: ↑Wed Aug 04, 2021 4:46 pm is not it strange for a giant elliptical galaxy like Centaurus A to have a dusty disk full of young giant stars, too?
A pair of jets is somewhat more typical. M87 has those too.

johnnydeep wrote: ↑Wed Aug 04, 2021 6:19 pm Thanks for the links bystander (and neufer). (bystander - your "original image" link is broken.)

bystander wrote: ↑Wed Aug 04, 2021 11:22 pm https://www.scienceimage.csiro.au/libra ... 850//large

MarkBour wrote: ↑Wed Aug 04, 2021 11:33 pm
Wow, the EHT is fantastic. 60,000,000 magnification.

While we enjoy these images of black holes and such, I wonder when they're going to get around to using it for the purpose for which it was created (locating Alan Shepard's lost golf ball).

• The Lunar Reconnaissance Orbiter Camera (LROC) (50 cm/pixel) resolution
  came within a factor of 12 of finding that 4.267 cm ball.

https://en.wikipedia.org/wiki/Lunar_Reconnaissance_Orbiter wrote:

Apollo 14 landing site, 2009 photograph by Lunar Reconnaissance Orbiter

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<<The Lunar Reconnaissance Orbiter Camera (LROC) comprises a pair of narrow-angle push-broom imaging cameras (NAC) and a single wide-angle camera (WAC). LROC has flown several times over the historic Apollo lunar landing sites at 50 km altitude; with the camera's high (50 cm/pixel) resolution, the Lunar Roving Vehicles and Lunar Module descent stages and their respective shadows are clearly visible, along with other equipment previously left on the Moon.>>

<<Under the rules of golf, a golf ball has a mass no more than 45.93 grams, has a diameter not less than 4.267 cm.>>