Space Exploration II: Always Looking up

[Kepler]

Second night, Canopus confirmed. Take a look at an object 310 light years away:




Relative size:



3 fun facts:

1. 400,000x the volume of the Sun.

2. Just 8x the mass of the Sun!

3. The parent star of Arrakis in Dune.

 

[Kepler]

3I/ATLAS makes its closest approach to Earth Friday night. It is predicted to drop to 11.3 magnitude, making it visible in my 8" Dobsonian. The trick will be locating it. I do not have a computer driven goto system or even a calibrated azimuth setting mount.

I will use star hopping. At the moment, 3I/ATLAS is the vertex of right angle with Regulus and Zosma in Leo, which means... I could actually find it.

If I somehow do I'll snap a shot.

 

[Kepler]

The resolution difference between a star (point source) and a planet (disk). Note how the star twinkles while the planet is steady:





Orion 8'' 1200mm Classic Dobsonian, Svbony 68 degree 9mm eyepiece, Celestron neutral density moon filter (25%).

 

[Kepler]

So, I was worried that I had misunderstood about 3I/ATLAS and "closest approach" would not equal "maximum brightness" because I checked this site Thursday morning and the magnitude was 15.6 -- way, way dimmer the faintest object I can see even in perfect conditions with my scope (roughly 13.5 -- magnitude are brighter the lower the number is). Welp, I checked just now, 24 hours later, and it is up to 11.3! Each unit in magnitude equals a brightness difference of 2.5x, so 3I/ATLAS increased more than 10x in brightness in one day! To put that in perspective, Venus' variance between brightest and dimmest, which is quite dramatic by standards of astronomical objects, is 2 magnitudes (5x). That takes 110 days.

 

[Handyman]

Jonathan Cohn (@jonathancohn.bsky.social)

16 Democratic senators joined Republicans in confirming a close ally of Elon Musk as head of NASA: Baldwin Cantwell Durbin Fetterman Gallego Gillibrand Hassan Heinrich Kaine Kelly Kim King Schiff Shaheen Slotkin Warner

bsky.app

 

[Kepler]

Kelly makes me put outrage on pause. He is certainly the only Member with even a smidge of understanding the relevant technical and political issues. Yes, I know, he was only the bus driver, not an astronomer, but he does have more of an appreciation of what NASA needs that almost any of us (our rocket scientist is on the clock).

I gotta hear him explain before I defenstrate.

It is most likely the crass grift for keeping funding of AZ space companies in which case fuck him. But let's say there is a non-trivial chance he has a legit reason.

 

[Kepler]

Amateur livestream from last night. He was getting 50k views a night until the last 2 weeks. Now it's half a million.

It is really quite something to see an astronomical object move in real time against the star backdrop. It happens in SF movies all the time, but in real life, other than artificial satellites, that does not happen. 3I/ATLAS is very close and it is not dawdling.

 

[Kepler]

More modest morning Mercury:

 

[Kepler]

3I/ATLAS makes its closest approach to Earth Friday night. It is predicted to drop to 11.3 magnitude, making it visible in my 8" Dobsonian. The trick will be locating it. I do not have a computer driven goto system or even a calibrated azimuth setting mount.

I will use star hopping. At the moment, 3I/ATLAS is the vertex of right angle with Regulus and Zosma in Leo, which means... I could actually find it.

If I somehow do I'll snap a shot.

It maxed out at 11.3 but I was unable to find it.

Highest resolution photo I could find, from Hubble in July. Damn nice shot. We are talking about an object 7 miles wide which at the time of the photo was 258 million miles away! Note the streaks are because the telescope is tracking 3I/ATLAS to maximize exposure. It is actually the object moving against an (almost) stationary backdrop, not the reverse.