1
00:00:00,000 --> 00:00:07,000
Hubble has delivered an unrivalled snapshot of nearby barred spiral galaxy NGC 1672. 

2
00:00:07,000 --> 00:00:12,000
This remarkable image provides a high-definition view of the galaxy’s large bar,

3
00:00:12,000 --> 00:00:17,000
its fields of star-forming clouds and its dark bands of interstellar dust.

4
00:00:34,000 --> 00:00:36,000
This is the Hubblecast!

5
00:00:36,000 --> 00:00:41,000
News and Images from the NASA/ESA Hubble Space Telescope. 

6
00:00:41,000 --> 00:00:46,000
Travelling through time and space with our host Doctor J a.k.a. Dr Joe Liske.

7
00:00:47,000 --> 00:00:49,000
Welcome to the Hubblecast! 

8
00:00:50,000 --> 00:00:54,000
Now when we look around us in the Universe with powerful telescopes, 

9
00:00:54,000 --> 00:00:58,000
essentially all the light we see comes to us from billions and billions of stars.  

10
00:00:58,000 --> 00:01:02,000
And these stars are gathered together in galaxies. 

11
00:01:02,000 --> 00:01:08,000
So, galaxies are essentially just huge collections of stars, gas and dust,

12
00:01:08,000 --> 00:01:12,000
and they come in an enormous variety of different shapes and sizes.

13
00:01:12,000 --> 00:01:23,000
Now, today I’d like to talk to you about one particular galaxy and that's NGC 1672 located in the Dorado or Swordfish constellation.

14
00:01:23,000 --> 00:01:29,000
Now here is a spectacular brand new image from the NASA/ESA Hubble Space Telescope 

15
00:01:30,000 --> 00:01:34,000
As you can see straight away it is a spiral galaxy.

16
00:01:34,000 --> 00:01:42,000
In fact it is a prototypical example of a so-called barred spiral galaxy and it is viewed nearly faced on. 

17
00:01:42,000 --> 00:01:48,000
Barred spirals differ from normal spiral galaxies, in that their arms do not twist all the way into the centre. 

18
00:01:48,000 --> 00:01:51,000
Instead, they are attached at two ends of a straight bar of stars. 

19
00:01:53,000 --> 00:02:00,000
Four principal arms extend from the centre and give NGC 1672 a rather symmetric appearance. 

20
00:02:00,000 --> 00:02:07,000
Eye-catching dust lanes extend away from the nucleus and follow the inner sides of the spiral arms. 

21
00:02:08,000 --> 00:02:14,000
Hot, young blue stars are seen in vigorous star forming clusters in the galaxy’s spiral arms. 

22
00:02:14,000 --> 00:02:20,000
Delicate curtains of dust partially obscure the light of the stars behind them and colour them red.

23
00:02:22,000 --> 00:02:28,000
NGC 1672 is almost like a sister galaxy to our own galactic home, the Milky Way. 

24
00:02:28,000 --> 00:02:32,000
The Milky Way also has a huge bar of stars, 

25
00:02:32,000 --> 00:02:38,000
which was recently seen in great detail by the infrared eyes of the NASA Spitzer Space Telescope. 

26
00:02:38,000 --> 00:02:43,000
The two galaxies also have in common that their spiral arms are quite loosely wrapped.

27
00:02:44,000 --> 00:02:49,000
Now, astronomers believe that barred spiral galaxies have a unique mechanism

28
00:02:49,000 --> 00:02:55,000
that channels gas from the disk inwards towards the centre of the galaxy. 

29
00:02:55,000 --> 00:03:03,000
And it is thought that this gas also makes a really good meal for a putative supermassive black hole that sits at the centre. 

30
00:03:03,000 --> 00:03:07,000
Moreover, bars are thought to be quite short-lived. 

31
00:03:07,000 --> 00:03:14,000
So, the big question is: will non-barred spiral galaxies develop the bar in the future,

32
00:03:14,000 --> 00:03:19,000
or have they hosted a bar in the past that has since died out?

33
00:03:20,000 --> 00:03:24,000
Behind the galaxy several more distant galaxies are seen. 

34
00:03:24,000 --> 00:03:28,000
They are coloured caramel by the dust in NGC 1672. 

35
00:03:28,000 --> 00:03:35,000
Also seen in the image are a few bright, much closer, foreground stars from our own Milky Way. 

36
00:03:37,000 --> 00:03:41,000
Astronomers are still puzzled about how bars actually form. 

37
00:03:41,000 --> 00:03:46,000
They could be the result of instabilities in the disk that harbours the spiral arms, 

38
00:03:46,000 --> 00:03:50,000
or they could develop in the aftermath of galactic collisions. 

39
00:03:50,000 --> 00:03:54,000
In any case, the formation and evolution of bars is still a matter of debate.

40
00:03:55,000 --> 00:03:58,000
This is Dr J signing off for the Hubblecast. 

41
00:03:58,000 --> 00:04:03,000
Once again nature has surprised us beyond our wildest imagination …

42
00:04:06,000 --> 00:04:11,000
Hubblecast is produced by ESA/Hubble at the European Southern Observatory in Germany. 

43
00:04:11,000 --> 00:04:16,000
The Hubble mission is a project of international cooperation between NASA and the European Space Agency.