Archive for the ‘NASTRO’ Category

Chasing an asteroid

Posted: February 14, 2013 in Minor Planets, NASTRO, Observing
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On Friday an asteroid, named 2012DA14, with a mass of about 190,000 tons will zip past the Earth.  For a brief time it will be even closer than the ring of satellites broadcasting weather images and TV signals around the globe.  NASA has great background information and simulations of the event.

2012DA14Flyby

Prior to closest approach 2012 DA14 will be best seen from the southern hemisphere.  The orbit brings the asteroid towards us from beneath the south pole of the planet.  2012 DA14 is expected to be at its closest to Earth – just 27,700 km (17,200 miles) above the surface – at 1924UT (7.26pm GMT).

There is no danger of a collision with the Earth or any satellites.  But amateur astronomers around the world will be trying to catch a glimpse of this rocky visitor near the time of its closest approach.  I’m one of those astronomers hoping for a clear sky on Friday evening so I’ve spent a bit of time preparing myself for the event.

I’m going to try to view the asteroid from Northumberland and at the moment of close approach 2012 DA14 will be below the horizon.  But it is moving very rapidly through the sky and will rise above the horizon in Northumberland at about 25 minutes later.

Here is a chart generated with SkyTools 3 showing the path of 2012 DA14 after it rises in Northumberland on the evening of Friday February 15th.  Note that the times given in the following star charts may be in error by several minutes – the orbit of the asteroid is not precisely determined enough to make timings without giving that caveat.

Asteroid_2012_DA14

To observe the asteroid I’m going to use a small telescope – an 80mm refractor – and choose a part of the sky that I know the asteroid will pass through.  I’ll start looking about 15 minutes before the asteroid is due to arrive at that spot.

The asteroid, predicted to have a brightness of around 7th magnitude at 8pm (just visible with binoculars) will be in the constellation Virgo, close to the border with Leo.  From Hauxley, it probably won’t be possible to see it until it is good altitude above the horizon.  I think I’ll be able to pick it up visually with the 80mm telescope at about 8.20pm as it cruises past the large scattering of stars in Coma Berenices called Collinder 256.  At that time, the asteroid will be tracking across the sky at 37 arcseconds per second.  In other words, it will cover a distance in the sky just smaller than the size of Jupiter every second.  Definitely detectable against the background stars.

By 8.40pm the asteroid will be passing the constellation Canes Venatici – just beneath the familiar seven stars of The Plough.  Larger telescopes will see it tumble past the Silver Needle galaxy (NGC4244) – an edgeways on spiral galaxy glowing at 10th magnitude.  At 9.04pm the asteroid passes close to another galaxy in Canes Venatici;  M106 is a spiral galaxy whose elongated glow will be visible with medium sized telescopes fairly easily.  By this time the asteroid will be shining at 9th magnitude and fading as it recedes from Earth.

After 9.15pm the asteroid is seen against the familiar backdrop of The Plough – probably the most recognisable pattern of stars in our northern sky.  The chart below shows the trajectory of asteroid during a 45 minute period when it should be easier for novice astronomers to locate.

2012da14_plough

At 9.34pm the asteroid passes between two bright stars of The Plough – Alioth and Phad.  This might be the easiest opportunity for inexperienced astronomers to find the asteroid with a telescope.  Although dimmer by a factor of 2 compared to closest approach, it will be much easier to detect with UK based telescopes because it is much higher in the eastern sky.

By 10pm the asteroid is shining at 10th magnitude and travelling across the sky just one-third as fast as it was a couple of hours earlier.    While it remains an easy target for larger telescopes it will continue to slow (relative to the background sky) and fade.  The final chart shows 2012 DA14 as it heads towards Polaris and the north celestial pole of the sky during the early hours of the 16th.

2012da14_draco

Here’s hoping for clear skies, no technical problems with the ‘scope and a hot pizza on a cold night!

Meteor/fireball on March 3rd

Posted: March 4, 2012 in Meteors, NASTRO

A wonderful night of observing at Hauxley Observatory last night.  I went with goal of getting some reasonably good pictures of the planet Mars.  But the highlight came at 9.41pm during a brief spell outside the observatory.  We all saw a bright meteor (a fireball) streaking across the sky from north to south.  Video footage here.  It was widely seen by people right across the UK.  It put me in mind of footage I’ve seen of an asteroid skimming the upper atmosphere and heading back into space.  Hopefully enough people captured this event on video or in pictures for the orbit of the object to be derived (and the possible trajectory after it disappeared).

Although it was bright (estimates I saw placed it at magnitude -9) it was probably only a metre or so in size (perhaps larger if if was made of icy material).  The slow moving appearance of the meteor was a combination of its distance and slow speed relative to us.  By slow, I mean it was probably moving at 10-20 km/s relative to us.  Since meteors typically occur at 60-120km above the ground, and this one wasn’t that high in the sky, it was actually hundreds of kms away from us at closest approach.

I’m done speculating on this until more data is available.

Astronomy course notes (part 1)

Posted: February 11, 2012 in NASTRO

Stargazing Live events occupied most of my free time in January. Now it’s the turn of the NASTRO 2012 Astronomy Course. The first session – featuring copious amounts of cold, rainy weather – began last Thursday. I’ve made the course notes from that session available on my website.

NASTRO Binocular 75

Posted: November 13, 2011 in Deepsky, NASTRO, NB75, Observing

This post is a follow up to the presentation I gave at the NASTRO meeting last Thursday.

The NASTRO Binocular 75 (NB75) is an observing list that I compiled nearly 10 years ago.  There are lots of lists or catalogues that are familiar to amateur astronomers.  The Messier and Caldwell catalogues are famous examples.  My reasons for drawing up a new list were:

  • I wanted an observing list I could complete; several Messier objects aren’t visible from Northumberland. No closure!
  • As Training Officer at NASTRO, I wanted a list of bright objects potentially visible with binoculars that members could use to hone their observing skills (like reading star charts, or using astronomy software as well as star hopping)
  • Knowing about more objects to track down will add variety.  I’ve seen so many people revisiting the same dozen or so objects in the night sky because they can’t find (or don’t know about) anything else that they can see.
  • It was fun to do.
There are very few current members of NASTRO who saw the list in its first form so I feel I can put it out again.  Also, with social networking more familiar to people these days, then hopefully some degree of collaboration between local astronomers will be possible.
I’ve no doubt that anyone undertaking the list will become totally familiar with the night sky by the time they’ve tracked down the 75th object.
So, without further ado, here is the list of all 75 objects.

ID

Name Class Con RA Dec

Mag

Size

Best Difficulty

1

M 31 Gal And 00h43m25.9s +41°20’19”

4.3

2.6°x 1.1°

obvious

2

ET Cluster Open Cas 01h20m23.8s +58°21’12”

5.1

20.0′

obvious

3

M 103 Open Cas 01h34m14.6s +60°42’53”

6.9

5.0′

obvious

4

M 33 Gal Tri 01h34m33.6s +30°43’28”

6.4

61.7’x 36.3′

easy

5

Collinder 463 Open Cas 01h46m48.8s +71°52’23”

5.8

57.0′

easy

6

NGC 663 Open Cas 01h47m02.4s +61°17’53”

6.4

14.0′

obvious

7

NGC 752 Open And 01h58m26.3s +37°50’46”

6.6

75.0′

detectable

8

Muscle Man Cluster Open Cas 02h15m38.5s +59°32’35”

4.4

60.0′

obvious

9

Perseus Double Cluster Open Per 02h19m54.3s +57°11’08”

4.3

18.0′

obvious

10

M 34 Open Per 02h42m54.1s +42°48’52”

5.8

35.0′

easy

11

Collinder 33 Open Cas 03h00m20.0s +60°26’52”

5.9

39.0′

easy

12

Collinder 39 Open Per 03h25m13.6s +49°54’16”

2.3

5.0°

easy

13

M 45 Open Tau 03h47m45.0s +24°09’16”

1.5

120.0′

obvious

14

Kemble’s Cascade (& NGC 1502) Open Cam 04h08m57.8s +62°21’45”

4.1

8.0′

obvious

15

NGC 1528 Open Per 04h16m20.7s +51°14’39”

6.4

16.0′

obvious

16

NGC 1545 Open Per 04h21m54.3s +50°16’51”

4.6

18.0′

obvious

17

Hyades Open Tau 04h27m37.0s +15°53’38”

0.8

5.5°

obvious

18

NGC 1647 Open Tau 04h46m39.1s +19°08’12”

6.2

40.0′

easy

19

NGC 1746 Open Tau 05h04m35.7s +23°47’10”

6.1

42.0′

easy

20

M 38 Open Aur 05h29m30.5s +35°51’23”

6.8

20.0′

easy

21

NGC 1981 Open Ori 05h35m46.3s -04°25’24”

4.2

28.0′

obvious

22

Collinder 69 Open Ori 05h35m47.4s +09°56’27”

2.8

70.0′

obvious

23

M 42 Neb Ori 05h35m55.0s -05°22’30”

4

40.0’x 20.0′

obvious

24

NGC 1977 Neb Ori 05h35m55.2s -04°50’30”

7

20.0′

difficult

25

Orion’s Belt Open Ori 05h36m08.2s -01°05’31”

0.6

2.3°

obvious

26

M 36 Open Aur 05h37m07.7s +34°08’45”

6.5

10.0′

obvious

27

M 37 Open Aur 05h53m07.0s +32°33’16”

6.2

14.0′

obvious

28

37 Cluster Open Ori 06h09m06.5s +13°57’44”

7

5.0′

obvious

29

M 35 Open Gem 06h09m45.8s +24°20’47”

5.6

25.0′

obvious

30

NGC 2175 Open Ori 06h10m23.5s +20°29’00”

6.8

22.0′

easy

31

NGC 2232 Open Mon 06h27m52.0s -04°45’55”

4.2

53.0′

obvious

32

NGC 2244 Open Mon 06h32m34.7s +04°55’58”

5.2

29.0′

obvious

33

NGC 2264 Open Mon 06h41m39.1s +09°52’59”

4.1

39.0′

obvious

34

M 41 Open CMa 06h46m33.3s -20°46’05”

5

39.0′

easy

35

NGC 2281 Open Aur 06h49m09.3s +41°03’42”

7.2

25.0′

easy

36

NGC 2301 Open Mon 06h52m23.3s +00°26’44”

6.3

14.0′

obvious

37

M 50 Open Mon 07h03m17.9s -08°24’01”

7.2

14.0′

easy

38

M 47 Open Pup 07h37m09.2s -14°30’32”

4.3

25.0′

obvious

39

M 46 Open Pup 07h42m20.1s -14°50’13”

6.6

20.0′

easy

40

M 48 Open Hya 08h14m19.4s -05°47’09”

5.5

30.0′

easy

41

M 44 Open Cnc 08h41m06.1s +19°37’19”

3.9

70.0′

obvious

42

M 67 Open Cnc 08h51m58.1s +11°45’14”

7.4

25.0′

detectable

43

M 81 Gal UMa 09h56m31.5s +69°00’09”

7.8

21.9’x 10.5′

easy

44

Collinder 256 Open Com 12h25m41.4s +26°01’57”

2.9

120.0′

obvious

45

Mizar DVar UMa 13h24m22.6s +54°51’39”

2.1

obvious

46

M 3 Glob CVn 13h42m43.2s +28°19’04”

6.3

18.0′

easy

47

M 5 Glob Ser 15h19m09.6s +02°02’30”

5.7

23.0′

easy

48

M 13 Glob Her 16h42m05.5s +36°26’25”

5.8

20.0′

obvious

49

M 12 Glob Oph 16h47m50.7s -01°57’56”

6.1

16.0′

easy

50

M 10 Glob Oph 16h57m46.3s -04°06’59”

6.6

20.0′

easy

51

M 92 Glob Her 17h17m27.8s +43°07’40”

6.5

14.0′

obvious

52

IC 4665 Open Oph 17h46m52.7s +05°42’55”

5.3

70.0′

easy

53

M 23 Open Sgr 17h57m45.9s -18°59’05”

5.9

29.0′

easy

54

Collinder 359 Open Oph 18h01m41.5s +02°54’10”

3

4.0°

easy

55

M 20 Neb Sgr 18h03m05.2s -22°59’07”

6.3

16.0’x 9.0′

challenging

56

M 8 Neb Sgr 18h04m45.6s -24°23’07”

5

17.0’x 15.0′

easy

57

M 24 Open Sgr 18h19m07.8s -18°24’01”

11.1

6.0′

challenging

58

M 16 Neb Ser 18h19m28.8s -13°48’45”

6

9.0’x 4.0′

difficult

59

M 17 Neb Sgr 18h21m29.1s -16°10’34”

6

11.0′

difficult

60

NGC 6633 Open Oph 18h27m49.6s +06°31’08”

5.6

20.0′

obvious

61

M 25 Open Sgr 18h32m29.0s -19°06’23”

6.2

29.0′

easy

62

M 22 Glob Sgr 18h37m07.5s -23°53’32”

5.2

32.0′

easy

63

Epsilon Lyrae (Double Double) Doub Lyr 18h44m43.4s +39°41’16”

4.7

obvious

64

M 11 Open Sct 18h51m43.3s -06°15’12”

6.1

32.0′

easy

65

Collinder 399 Open Vul 19h25m55.1s +20°12’42”

4.8

89.0′

easy

66

M 27 PNe Vul 20h00m07.3s +22°45’32”

7.3

8.0′

obvious

67

NGC 6871 Open Cyg 20h06m25.9s +35°49’01”

5.8

29.0′

obvious

68

NGC 7039 Open Cyg 21h11m14.2s +45°40’20”

6.8

14.0′

obvious

69

M 15 Glob Peg 21h30m33.3s +12°13’24”

6.3

18.0′

easy

70

M 39 Open Cyg 21h32m14.6s +48°29’35”

5.3

29.0′

obvious

71

M 2 Glob Aqr 21h34m04.6s -00°46’02”

6.6

16.0′

easy

72

Garnet Star DVar Cep 21h43m53.2s +58°50’31”

4.3

obvious

73

NGC 7243 Open Lac 22h15m37.5s +49°57’52”

6.7

29.0′

easy

74

M 52 Open Cas 23h25m22.5s +61°39’55”

8.2

15.0′

easy

75

NGC 7686 Open And 23h30m43.2s +49°12’18”

5.6

14.0′

obvious

I compiled the list using SkyTools 3.  It’s ordered by Right Ascension, which approximately means that the objects at the top of the list were well placed in the sky at midnight at the start of Autumn.  So now, near the middle of November, it should be possible to track down the first 15 or 20 objects before late evening.

The list contains a number of different types of object:

Here is the 65th entry in the NB75 list – The Coathanger.

Collinder 399 in the constellation Vulpecula. Popularly known as the Coathanger. Image by Malcolm Robinson.

The response from NASTRO members seemed enthusiastic.  The list is a starting point; each object has an interesting back story and will add a little (or a lot) to your picture of the universe.
I’ll discuss this more and add some more resources to support this soon.  Emma will be adding things to the main NASTRO website as well.

Just had a quick look at the path predicted by SkyTools 3 software using the most up to date orbital elements. Best chance to see it from Northumberland will be immediately after dusk; the asteroid will be racing eastwards across the sky through the constellations Ophiuchus, Serpens, Aquila and Delphinus between about 6.30pm and midnight. As the stars and constellations set in the west, the rapid eastward motion of the asteroid delays the moment it drops below the UK horizon until the early hours of the 9th.

Here’s a chart generated for Northumberland showing the path of the asteroid 2005 YU55 on the evening of November 8th.

Motion of 2005YU55 on November 8th 2011. Courtesy of SkyTools 3.

The time is shown next to the track at approximately 20 minute intervals.  As for observing the asteroid – you’ll need much more detailed star charts than the one above.  Here’s the position of the asteroid over a shorter time scale and shown on a much more detailed chart.

Motion of 2005YU55 between 7.15pm - 7.45pm on November 8th 2011. Courtesy of SkyTools 3.

So you’d use the wide-field chart to pin down the location of the small-field chart.  In reality, because the asteroid must be observed with a telescope, you’d probably need something like SkyTools to generate an even smaller field of view  – perhaps an eyepiece view.  The star labels might be confusing if you’re not used to them.  For example 61 Ser (60) indicates the star called 61 Serpentis and the number in brackets indicates the brightness (magnitude 6.0).  Fainter stars shown in the picture simply have number representing the magnitude (brightness) of the star.

Consider these factors:

  • Predicted brightness is around magnitude +12 to +13.
  • The asteroid is being viewed against the backdrop of the Milky Way; a crowded star field will make this a difficult object to spot.
  • Low altitude above the horizon all evening; the best opportunities to view will be as soon as dusk has fallen.
  • Strong moonlight interference from a nearly full moon.
  • Strong light pollution for sites north of Newcastle in that direction.
Despite all of this I’ll be at Hauxley with the 16 inch Dob trying to spot this faint speck of light moving against the distant stars of the Milky Way.  Weather permitting of course.
It’s possible that the viewing conditions may be better on Wednesday 9th; the asteroid will be further from Earth but more fully illuminated than the previous evening.  It’ll also be higher in the sky.  The downside is that it will be fairly close to the moon in the evening sky.  I’ll post an update for viewing YU55 that night closer to the time.

Picture of a Giant Planet

Posted: November 1, 2011 in Imaging, NASTRO, Planets

Jupiter – it’s the easiest planet to get images of.  Me and Emma were at the observatory at Hauxley this evening.  Here’s an image of Jupiter taken with a Meade DSI II on the 14 inch Meade LX200.  The Great Red Spot is visible and the moon Io is on the right of the image.  More to follow.  Must sleep now…

NASTRO Star Camp 2011

Posted: October 30, 2011 in NASTRO

Just got back from NASTRO’s second Halloween star camp.  Not many stars to be seen over the two nights of the camp at Barrowburn, but just enough of them during a clear spell on Friday night to suggest how fantastic the sky up there can be!  The old school house we stayed at is at the foot of a hill.  As some of the brighter stars rose and cleared it was hard not to think that the stars were lying along the edge of the hill.  This was a particularly strong illusion as the Pleiades rose.

Here’s a long exposure picture looking towards the hill top as Jupiter rose:

The exposure was 15 minutes but the passing clouds add an orange glow to the otherwise dark sky.

Saturday was mostly cloudy so we stayed in and played games like “Who am I?” or “What am I?”  Oliver proved to be difficult to beat at this…..he came up with PIG (pipeline inspection gauge) for his.  I mean, who would have got that one?

Sunday morning: pork and apple sausages and bacon sandwiches…..just the think after an uncomfortable couple of nights on slowly deflating air beds.  Next Star Camp in late February 2012.