Starship Asterisk*

Doesn't require any experience. Everyone I have shown these two can see the the colour without any prompting. Even people who have never looked through a scope in their life before.

I have never liked planetary nebulas much. The reason is precisely because I wasn't able, for the longest time, to figure out what color they really are, or why. (Now I think I know - they glow at 501 nm and 656 nm.) The wild and strange colors in Hubble images of planetaries made me go off planeta...

Congratulation, beautiful picture! I would be interested to know why two images had to be overlaid? Why it was not possible at one time? The usual reason is that the sky is imaged using a long exposure with the camera on an equatorial tracking mount. This stops the stars trailing but blurs the fore...

Sorry if I've already asked this in the past. Whenever I look at such photos, I always wonder, which one of the bright objects (of various sizes, shapes and colors) we see are stars and which ones are galaxies. There are some photos wherein every object (almost every) is a galaxy. But, some have a ...

A question, SVP: Lovely photo, but how many of the “several hundreds of thousands” of stars can be individually analyzed and converted into data points in the H-R diagram? Surely not even one of several hundreds of thousands. Sooo.... how can they be sure they have a representative sample? Couldn’t...

JohnD wrote: ↑Thu Apr 11, 2019 9:39 am But hang on! These are RADIO telescopes! Why did a little bad weather threaten their seeing?

As mentioned earlier in the thread, they are using a wavelength of 1.3mm. This is at the short end of the microwave spectrum, which would be strongly attenuated by clouds and rain.

Thats awesome. But would it be being difficult to ask how it is that radio telescopes can 'see' or resolve such stuff, at the minute angles and immense distances that this is being observed at ? Resolution is proportional to wavelength divided by aperture. The answer is that they have a large effec...

The carbon star DY Crucis is interesting to observe in contrast to the adjacent 1st magnitude Beta Crucis (Mimosa). The two are separated by only a bit over two arc minutes. There is a big difference in brightness but that seems to enhance the deep red colour of DY Crucis.

Nice animation. Northern hemisphere centric though

I heard that Gaia's mission is to take up to 70 snapshots of its targets over 5 years [Wikipedia], and the elapsed time since Gaia's launch is 4 years, 4 months, and 27 days, I'd say the time period is around 4 years and 4 months. (Just my unofficial guess.) DR2 covers the first 22 months of data c...

ata Which time span is displayed or extrapolated in this picture? I heard that Gaia's mission is to take up to 70 snapshots of its targets over 5 years [Wikipedia], and the elapsed time since Gaia's launch is 4 years, 4 months, and 27 days, I'd say the time period is around 4 years and 4 months. (J...

Adriano wrote: ↑Wed May 16, 2018 5:54 am Superb picture. Is there a black hole at the centre of LMC?

Some evidence:

https://arxiv.org/abs/1804.10197

When I first saw today's Announcement; I thought old Eta might have finally blown her self up! Imagine the disappointment! I guess not as much disappointment as when a certain Professor recently announced the discovery of a > 1st magnitude transient in Sagittarius which turned out to be Mars :lol2:

It looks like the Southern hemisphere viewpoint but Gemini is out of place? Should be Taurus, Orion, Gemini then Cancer when looking at the Southern hemisphere Northern Sky going from from West to East

I have seen the albedo estimated to be around ten percent which isn't a lot different to the Moon. Quite dark compared to icy bodies if the estimates are accurate. I wouldn't make any guess at origin since it's speed relative to the Sun (when the asteroid was well out in interstellar space) is quite...

A deep look at Omega Centauri ( NGC 5139 ) Capture: 9 sets of sub-images with exposure duration for each set doubling ( 1s to 240s ) all at ISO800. Processing:. Calibration: master bias, master flat and no darks. Integration in 9 sets. HDR combination. Pixinsight May 2017 Hi Mike, Great image. I'm ...

Anyone know the orbital period of each planet? I saw a range from 1.5 to 12 days mentioned but not the individual period of each planet. I'm wondering how stable the arrangement is.

"Some cruel people also suggest that astronomers' dandruff falling on a positive image could be mistaken for stars!"

Makes me wonder if some star catalogues have any dandruff listed in them and what the spectral type would be.

The distance to the cluster is (maybe was) a small controversy. Radio telescope VLBI and a number of other methods measured the distance at around 135 parsecs, whereas the ESA Hipparcos satellite gave a result around 118 parsecs, well outside the margin of error. The first data release from the ESA ...

It's interesting that Aristarchus and other Greeks of the time had proposed the heliocentric view. Even the Roman's Pliny and Seneca wrote that the retrograde motion of the planets was merely "apparent". That suggests that the heliocentric model was more widely accepted than is often state...

On Pluto the Sun is between 150 and 450 times as bright as the full Moon as seen from Earth. The range of brightness relates to Pluto's elliptical orbit. Even when Pluto is at aphelion, you would have no trouble seeing stuff on Pluto's day side.

You mean like the perfect circle traced out by stars in the top 1/5th of the picture, immediately below the word April? Yes: even if the stars seem to say Vote Trump, it is random. Every now and then I'll spot a straight line of stars in an image, something like 7 in a row. Enough for me to stop an...

The Gaia data will also improve many of the other methods. For example, they will get accurate parallax measurements of a considerable number of Cepheid variables allowing improved calibration of that method.

That's really interesting to know. Going forward I will need to look a little more critically at the distances published in Astronomy related articles. It would be nice if quoted distances were accompanied in brackets by some form of abbreviation which would define either the measurement technique ...

I wonder if any associated GRB was detected?