Sunspot grouping

by James Weightman

Huge Sunspot Group

Sunspots are dark regions on the surface of the Sun that appear darker than the surrounding area. They are caused by strong magnetic fields that emerge through the photosphere, or surface, of the Sun.

Sunspots consist of two main regions:
the Umbra: a central dark region, which is cooler (about 3500°C) compared to the surrounding photosphere (about 5,500°C),
and the Penumbra: the surrounding region that is also cooler and lighter.

On average, sunspots are about the same size as Earth, although they can vary significantly in size from hundreds to tens of thousands of miles across; a group of sunspots as seen in these photos is known as an ‘active region’.

The frequency and intensity of sunspots visible on the Sun’s surface indicate the level of solar activity during the 11-year solar cycle which is driven by the Sun’s magnetic field. Sunspots play a significant role in generating solar flares and coronal mass ejections (CMEs), which can impact space weather and Earth’s environment.

Automated precision counting of small lunar craters – A regolith evolution model.

By Peter Cadogan.

I will be presenting at the European Lunar Symposium 16th-21st June 2024.  https://sservi.nasa.gov/els2024/

This article is available for members to view in the Mercury section. 

Extract:

Introduction: Lunar craters as small as 2.5m in diameter have been counted at many sites  cross the lunar surface, mainly mare ones [1]. The very large counts allow them to be plotted as size frequency histograms (CSFH), rather than cumulative distributions, enabling  subtle differences between sites to be more clearly revealed. The results for the ejecta blanket of Giordano Bruno crater, combined with current cratering rates determined by temporal imaging [2], are consistent with its age being about 10Ma [3], confirming that even  the very smallest craters formed during this period still exist today.

CAS Sky Notes for June 2024

The summer solstice occurs on the 20th June and skies are too light too late for any deep sky astronomy.  Astronomical twilight now lasts all night, so there will be a permanent glow in the north, even at midnight.

Aurora

Hopefully many of you saw the recent display of Aurora, courtesy of a huge sunspot group on the Sun emitting flares and a Coronal Mass Ejection (CME).

It was a magnificent sight and so rare to see anything like that at these latitudes.  We were blessed with, not just a green glow in the north. But reds and blues and pinks bursting overhead.  It is possible that there may be more displays if the sunspot group remains.  Also, the Sun is around its maximum activity and may produce more aurorae.  Keep an eye out and maybe download an aurora alert App, such as Aurora Pro.

Planets

There are no planets visible in the evening sky this month.  There is an alignment of the planets in the morning sky of June 3rd before sunrise.

Of course, they are not really anywhere near each other, but the alignment is pretty.

Venus is not visible as it reaches superior conjunction (behind the Sun) on the 4th June.  Also, Uranus and Neptune require a telescope to be seen.

Mercury also reaches superior conjunction on the 14th June.

 

Moon

 6th June:  New Moon              14th June:  Moon is at First Quarter

22nd June:  Full Moon              28th June:  Moon is at last quarter

 Sun

The Sun is rather active currently, so watch out for large Sunspot groups.  Remember to never look at the Sun directly without a proper solar filter.

Meteors

June Bootids.  June 22nd to 2nd July. These occasionally have outbursts, so watch out for them.

 

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CAS Coordinator and Annual Financial Report 2024

The CAS Coordinator’s annual report, the Treasurer’s written report and statement of accounts is now available for members to view in the member’s only part of this website. Any questions should be submitted to the Coordinator in advance of the AGM on Saturday 11th May 2024.

CAS Sky Notes for May 2024

The lighter nights make astronomy more challenging now, especially as none of the planets are well placed. You may need to concentrate on the Moon.

Planets:

Mercury:  Mercury becomes a morning object, reaching elongation of -26o on the 9th May. However, it will be low in the sky and, although of magnitude +0.4, it will be difficult to find.

Venus:  Venus is technically a morning object but is not really observable as it approaches superior conjunction at the start of next month.

Mars: It remains a difficult morning object throughout at magnitude +1.1 and diameter of 4.8 arcsec. It continues to increase its declination to +7o, so you may be able to view it.

Jupiter:  Jupiter reaches conjunction on the 18th and so is not observable this month.

Saturn: Although Saturn rises well before the Sun in the morning sky, its southerly declination of -6o and magnitude of only +1.2 will make it a tricky object.

Uranus: Uranus is not observable this month.

Neptune:  Neptune is not observable this month.

The Sun

Solar activity is still increasing, providing a good opportunity for solar observations.

Take great care to never look directly at the Sun, or directly through an optical instrument.

Aurora Borealis:  Increasing solar activity increases the chance of seeing an aurora. There are a number of Apps that can give you warnings and chances of seeing Aurorae. Mine is called Aurora Pro.

Meteor Showers:  There are no observable meteor showers this month but keep an eye out for sporadic ones.

Moon

1st May:  Moon is at last quarter.                  8th May:  New Moon**

15th May:  Moon is at First Quarter               23rd May:  Full Moon      

Comet 12P Pons-Brooks

This may still be visible at the start of the month, although it is moving southwards. Look online for updated expectations.

Deep Sky Objects:  This is becoming increasingly difficult with the lighter nights. By the end of the month, astronomical twilight will last virtually all night. Only objects in the southern part of the sky will be able to be photographed successfully.

To view this post in PDF format please CLICK HERE

Reference material on Globular Clusters

Following on from the excellent talk last night (13 April 2024) by Owen Brazell, here are some links to sources of further reading that were given in the talk.

haroldcorwin.net globulars

British Astronomical Society Observing Programmes

astronomy-mall.com Adventures In Deep Space

faintfuzzies.com Globular Clusters PDF

There is more information in a PDF document, including some book titles, available to members. (The link is available when logged in to the website).

Members only - please login to view

CAS Sky Notes for April 2024

The change in the clocks and lighter nights become an increasing problem for observing.

Planets:

Mercury:  Mercury will still be visible in the evening sky at the very start of the month. This month, having reached greatest eastern elongation on the 24th March. It starts the month with an elongation of +17o, but rapidly drops to +11o by the 5th April. It will then rapidly be lost as it reaches inferior conjunction on 11th April; therefore, look for it early in the month.

Venus:  Venus is still a morning object but is rather difficult to see. Its elongation drops to -10o by the end of the month. Its magnitude remains at -3.8 as the phase increases to 98% by the end of the month as it approaches superior conjunction in June. The diameter remains around 10 arcsec during this month.

Mars: It remains a difficult morning object throughout at magnitude +1.1 and diameter of 4.7 arcsec. Its declination increases this month to +1o putting it a bit higher in the sky.

Jupiter:  Jupiter is becoming difficult this month, being low in the western sky after sunset. It is approaching conjunction in mid-May.

Saturn is not observable this month as it is still too close to the Sun in the morning sky.

Uranus is no longer visible this month as it sets not long after the Sun.

Neptune. Neptune is not observable this month.

The Sun

Solar activity is still increasing, and solar observations are a good idea.

Take great care to never look directly at the Sun, or directly through an optical instrument.

Aurora Borealis:  Increasing solar activity increases the chance of seeing an aurora. There are a number of Apps that can give you warnings and chances of seeing Aurorae. Mine is called Aurora Pro.

Meteor Showers:  The Lyrid meteor shower occurs between the 14th and 30th April. The peak is on the 22nd April, so the full Moon makes this rather unfavourable.

Moon

2nd   April:  Moon is at last quarter.              8th April:  New Moon**

15th April:  Moon is at First Quarter             23rd April:  Full Moon      

**There will be a total solar eclipse on the 8th April. This will not be visible at all in the UK.

Comet 12P Pons-Brooks This comet reaches perihelion on 21st April but may be visible low in the west after sunset. It could reach magnitude 4 and be visible to the naked eye, or at least in binoculars. Its brightness is unpredictable and prone to outbursts. I recommend you look online for the latest up to date information.

To view this post in PDF format please CLICK HERE

CAS Sky Notes for March 2024

Planets:

Mercury:  Mercury moves into the evening sky this month, having passed through superior conjunction on the 28th February.  It also moves north of the celestial equator and becomes well placed later in the month.  It reaches greatest eastern elongation of 19o on 24th March when it will be visible in the west after sunset. A week either side of the 24th may also see it relatively easy to find.

Venus:  Venus is still a morning object, but is less well placed.  Its elongation drops to 17o by the end of the month.  Its magnitude remains at -3.8 as the phase increases to 96% by the end of the month.  The diameter decreases to around 10 arcsec during this month.  Also, it remains well south of the celestial equator and so is low in the morning sky. 

Mars: It remains a difficult morning object throughout at magnitude +1.2 and diameter of 4.4 arcsec. Being well south of the equator renders it hard to find.

Jupiter:  Jupiter is still visible in the western sky after sunset and early evening.  It is quite high in the sky and unmistakeable. Look out for the 4 Galilean moons. Various websites will help you to identify them, www.shallowsky.com is worth using as it also shows the position of the Great Red Spot (GRS) and when it is visible.

Saturn is not observable this month as it has only just passed through conjunction.

Uranus is still observable.  It is situated roughly half way between Jupiter and the Pleiades and so is fairly easy to find.  R.A. 03h 05m, Dec +17o.  It lies to the west of the Pleiades. If anyone wants more details, please email Neil at coord@cotswoldas.org.uk

Neptune is not observable this month.

The Sun

Solar activity is still increasing and solar observations are a good idea.  Take great care to never look directly at the Sun, or directly through an optical instrument.

Aurora Borealis:  Increasing solar activity increases the chance of seeing an aurora.  There are a number of Apps that can give you warnings and chances of seeing Aurorae.  Mine is called Aurora Pro.

Meteor Showers:  There are no prominent meteor showers this month, but watch out for sporadic ones at any time

Moon

3rd March:  Moon is at last quarter.              10th March:  New Moon

17th March:  Moon is at First Quarter            25th March:  Full Moon**       

**There will be a penumbral eclipse of the Moon on the 25th March.  This occurs when the Moon passes through the fainter outer part of the Earth’s shadow.

It enters the penumbra at 04:53m UT. The Moon sets at 06:01 UT and the end of the eclipse, at 09:32, is therefore not visible in the UK.

Deep Sky Objects:  The Orion Nebula is an easy target throughout the night.  It is the middle ‘star’ in the sword, below the belt of three stars. The Andromeda Galaxy (M31) is well placed as is our other neighbour, the Triangulum Galaxy (M33).

Astrophotography Challenge: Try to get a really good photo of the Double Cluster in Perseus. RA: 2h 20m Dec: +57.08, almost overhead. You don’t need a powerful telescope, just a zoom lens as each cluster covers nearly 0.5o.

To view this post in PDF format please CLICK HERE

Visiting CAS

Trial Visits
If you are unsure about joining, you are welcome to attend a maximum of 2 monthly meetings as a visitor to see what you think of the Society. There is a small charge of £2 per person per visit, but if you join the Society during the evening of your visit the charge for that evening will be fully refunded. If you wish to continue beyond those 2 visits we will require you to become a member.

Our monthly meetings take place at Deer Park Archers, Shurdington.
See the map below or use the What Three Words app to obtain a precise location, using “shudders.stewing.genetics”. what3words.com/shudders.stewing.genetics

The turning off the A46 is rather hidden. Looking rather like a lay-by here is a photo:


Visitors are welcome!