Peter Hill

Solar Images in H alpha, Calcium K and Visible

Most of my solar images have been taken in visible or H alpha , the Baader CaK filter in conjunction with a Herschel wedge provides a relatively “cheap” way of imaging in CaK.

Images in Visible light give detail of the photosphere , which we can consider as the Suns “surface”, above this is the chromosphere, the upper part of which is viewed in H alpha and mid section can be viewed in Ca K wavelengths. (Not quite this simple as there is some overlap, but broadly works this way) The Cak is sensitive to magnetic fields and the stronger the magnetic filed the brighter the image, this gives more detail of the plages around sunspots and more detail of how magnetic field varies in these areas.

After some time setting up a system to image in all 3 wavelengths a fine clear day arrived on Friday 22nd June and I imaged the sunspots and prominences , then went away, which is why I’ve only just finished processing images.

All images were taken using a mono CCD camera : Imaging Source DMK41, the H alpha images were taken using a Coronado PST, the Visual White light images with a Herschel wedge with a ND.3 filter and Baader continuum filter on the camera, using a Skywatcher Evostar 120 refractor. The Cak images were taken with a Baader Cak filter attached to DMK41 and using a Herschel wedge with either a ND.3 or ND 0.6 filter on Skywatcher  ST102 ( for full disc) and / or Skywatcher Evostar 120. All Images were 600 frame avi’s stacked in AutoStakkert, wavelets tweaked in Registax 6 and final processing in Photoshop CS6. Not having imaged for a while I soon realised that I needed to do some cleaning before the next session as the “dust bunnies”  were more numerous than usual, luckily I was either able to manipulate image to avoid most of them or eliminate them in processing.

I have left the images as mono as features show up better for comparison rather than processing in false colour.

Whole disc in CaK and H alpha, no prominences visible in CaK.

 

 

 

 

 

 

 

 

 

 

 

 

 

Main surface features in Cak in Evostar 120, left to right : faculae, AR2715, AR2713

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Faculae in Halpha x2 barlow

 

 

AR2715 In Cak, Vis,  H alpha (x2 Barlow)

 

 

 

 

 

 

 

 

AR2713 in Cak, Vis , H alpha (x2 Barlow)

 

 

 

 

 

 

 

 

Prominences x2 Barlow

 

 

 

 

 

Moon and Venus 15/07/18

Now 2 days old the moon at 11% illumination presented it self in the evening sky at an elevation of approx. 12 degrees at 21:30, easily visible, unlike yesterday when I could only pick it out using binoculars.

Its companion this evening was Venus, easily visible unlike mercury of the previous evening. Didn’t have to travel any further than front lawn for these shots.

Day old moon (and Mercury?????)

The day old moon was setting on the 14th July with mercury in close attendance, well I went to my usual spot for these events, set up Canon 450D on tripod with cable shutter release and 150-500mm Sigma zoom lens. Sunset well into the NW around 21:30 then patiently scanned horizon in W to WNW direction with 7×50 binoculars for sign of moon which was going to be a thin crescent of approx 3.4%. The more worrying feature was a low cloud bank across the horizon ( see Andys previous post to this) which made for a glorious sunset but was going to cause problems trying to view Mercury and in fact as mercury was about 1-2 degrees to left of moon and about 2 degrees below it never punched through the murk. First image of moon was at 21:46 and last at 22:06 as it slipped into the cloud bank.

1.F6.3,ISO1600, 1/500″, 500mm

2. F5.6, ISO1600, 1/1250″,289mm

3. F6.3,ISO 1600, 1/400″, 500mm

4. F6.3, ISO1600, 1/30″, 150mm

 

 

 

June Meteors

No major activity in June , the June Lyrids the most active around the 15th/16th of June, the peak is distinguishable on the daily count plot. The peak activity around the 10/11th, is probably the combination of the Theta Opiuchids and Saggitariids.  The rest of activity during the month a combination of the many minor showers present.

The dip in the daily rate on the 6th is due to Graves being off line between 01-05 hrs. The activity has dropped of to about 50 meteors / day towards end of month and has continued at this rate into July which is a relatively “quiet” month.

The plot is similar to the daily plot from 2017, although rates lower( this is probably dependent upon the density of the debris field the earth passes through )

I’ve listed the showers for June below as are the daily and hourly plots for June 2018 and the daily plot for June 2017.

Moderate Activity:

Radiant Duration Maximum
June Lyrids June 10-21 Jun. 15/16

Minor Activity:

Radiant Duration Maximum
June Aquilids June 2-July 2 Jun. 16/17
June Boötids June 27-July 5 Jun. 28/29
Corvids June 25-July 3 Jun. 27/28
Tau Herculids May 19-June 19 Jun. 9/10
Ophiuchids May 19-July 2 Jun. 20/21
Theta Ophiuchids May 21-June 16 Jun. 10/11
Sagittariids June 10-16 Jun. 10/11
Phi Sagittariids June 1-July 15 Jun. 18/19
Chi Scorpiids May 6-July 2 May 28-Jun. 5
Omega Scorpiids May 19-July 11 Jun. 3-6
June Scutids June 2-July 29 Jun. 27/28

Daylight Activity

Radiant Duration Maximum
Arietids May 22-July 2 Jun. 7/8
Zeta Perseids May 20-July 5 Jun. 13/14
Beta Taurids June 5-July 18 Jun. 29/30

May Meteors.( Based on Graves Radar)

The main meteor shower in May is the Eta Aquarids,  it is however not the only shower and there are several daylight showers as well. The effect of this is for the “peak” of activity not to be situated around the 5th / 6th of June but elsewhere. This can be clearly seen on the daily and hourly plots for the month both for this year and last year.

Major Activity:

Radiant Duration Maximum
Eta Aquarids (ETA) April 21-May 12 May 5/6

Minor Activity

Radiant Duration Maximum
Epsilon Aquilids May 4-27 May17/18
May Librids May 1-9 May 6/7
Eta Lyrids May 3-12 May 8-10
Northern May Ophiuchids April 8-June 16 May 18/19
Southern May Ophiuchids April 21-June 4 May 13-18

 

Daylight Activity

Radiant Duration Maximum
Epsilon Arietids April 25-May 27 May 9/10
May Arietids May 4-June 6 May 16/17
Omicron Cetids May 7-June 9 May 14-25
May Piscids May 4-27 May 12/13

Review of RAG meeting 25/5/2018

Those members of the group not away for the bank holiday weekend turned up on a rainy evening to hear excellent talks by two of our own members: Peter Hill talked about radio meteor detection and the second talk was on meeting a UK astronomer by Paul Bertenshaw. This represents a new format to the evenings with separate before and after coffee speakers and went down well with everyone there. In the past a number of our members have used the opportunity to meet astronomers when they have given talks or hosted dinners in the UK and it was fantastic to hear Paul’s excitement as he talked about the experience and see His photos with the great man! I think I will book for the next one….

We have also made a decision to incorporate a members social time between 19:30 and 20:00 for the next three months, although everyone needs to ensure they arrive by 20:00 as the forestry centre entry barrier goes down at this time.

Andy

April Meteors

The main shower in April is the Lyrids, but as the table below shows there are other showers present as well.

Major Activity:

Radiant Duration Maximum
Lyrids (LYR) April 16-25 Apr. 22

Minor Activity:

Radiant Duration Maximum
Tau Draconids March 13-April 17 Mar. 31-Apr. 2
Librids March 11-May 5 Apr. 17/18
Delta Pavonids March 21-April 8 Apr. 5/6
Pi Puppids (PPU) April 18-25 Apr. 23/24
April Ursids March 18-May 9 Apr. 19/20
Alpha Virginids March 10-May 6 Apr. 7-18
April Virginids April 1-16 Apr. 7/8
Gamma Virginids April 5-21 Apr. 14/15

Daylight Activity:

Radiant Duration Maximum
April Piscids April 8-29 Apr. 20/21

The total meteor activity detected for April was 1790.

The average daily rate was 60 and the average hourly rate 2.5

The max hrly rate was 11  during the hours of 9 & 11 on 30th April

The max dly rate was 93 on 23rd April with hourly counts of 10 during the hours of 4, 9 & 11.

Maximum activity for the Lyrids occurred during daylight as did a lot of this months activity.

The daily rate graph and hourly rate graph are listed below, the Lyrid max is marked on both, the daily rate for 2017 is also included for comparison, it would appear more meteors were detected this year. The month of May brings the Eta Aquarids over the weekend of the 5th/6th, which will be competing with a bright waning Gibbous moon.

Pete H

 

Solar Array

Today allowed me to finally get my Solar array set up. After several attempts at balancing and positioning all the components and making modifications I was able to set up all 3 scopes in a balanced configuration.

Then using the Kendrick Solar finder on the central scope (Evostar 120) and setting the tracking to solar rate I then adjusted the alignment of the ST 102 and the PST, so that all 3 scopes showed full disk of sun in centre of field of view.

The idea is that:

the central scope will give white light images of the sun using a Herschel wedge with an ND3 filter.

the smaller ST102 refractor will give CaK images using a Herschel wedge without any filter and imaged with DMK41 mono ccd camera with Baader Calcium K filter fitted.

the PST will give H alpha images.

Today I was only using set up visually , to align scopes, so I used filtered Herschel wedge in the Evostar 120, a baader Solar film on front of ST 102 and the PST was used as normal. There were no sunspots visible and in H alpha a noticeable prominence at 4/5 o-clock position as registered by Roger this morning, no other prominences visible, nor was there much surface detail. No CaK detail as was not using camera, the sun was very variable , but there were enough bright spells this afternoon between 2 and 4pm to allow the alignment of all three scopes.

The mount was constructed with a piece of 10mm thick Aluminium bar 10cm wide and 35 cm long attached to upper side of lower vixen bar via two M6 bolts.

Two vixen bars were then attached to upper surface of Aluminium bar via M6 bolts, two sets of ADM mounting rings of suitable size were then clamped onto these vixen bars.

(ADM rings and vixen bars from First Light Optics.)

By adjusting screws in Rings I was able to align both scopes to get full disk in centre field of view, to remove scopes the top adjusting screw only in each ring is taken out, so when  scopes placed back in , tightening this screw only should put them back in aligned position, all bar a slight tweak.

To ensure the system was balanced about the axis running along the length of the Evostar, extra masses were added under the PST, these were attached via an M10 bolt with head removed and centre tapped with M6 thread, then attached to vixen bar with M6 screw head bolt through Vixen bar and M10 bolt to hold masses in place., this can be seen on photo below with scopes removed from rings.

By experiment on table top , approx. 1.5Kg was required on PST side to balance rig, brought 4 small masses from Astro Buy & sell, and drilled out centres to fit bolt. All we want now are some clear skies and sunspots!!

Thanks to Lee for advice on design and initial drilling and tapping of holes / threads.


 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

March Meteors

March is not blessed with a conspicuous meteor shower but there are plenty of minor showers overlapping.

Minor Activity

Radiant Duration Maximum
Eta Draconids March 22-April 8 Mar. 29-31
Beta Leonids February 14-April 25 Mar. 19-21
Rho Leonids February 13-March 13 Mar. 1-4
Leonids-Ursids March 18-April 7 Mar. 10/11
Delta Mensids March 14-21 Mar. 18/19
Gamma Normids (GNO) March 11-21 Mar. 16/17
Eta Virginids February 24-March 27 Mar. 18/19
Pi Virginids February 13-April 8 Mar. 3-9
Theta Virginids March 10-April 21 Mar. 20/21

Daylight Activity

Radiant Duration Maximum
March Aquarids February ??-April ?? Mar. 15-18

The total meteor activity recorded for the month using the fundongle pro+ on the Graves frequency was 1116, there was a daily average of 36 with an hourly average of 1.5 The maximum daily count was 60 recorded on 19th March as was the max hourly count of 13.

This peak activity coincided with the peak activity of the Beta leonids, delta mensids and eta Virginids. Other minor peaks can be identified using table above.

A post on the UK Radio Meteor discussion group on the 19th flagged up a long duration event picked up by an observer at Emsworth in Hampshire., I didn’t find any visual reports of this daytime event.

Checking my logs this event had also been recorded at Barton, although spread across two screens.

The event was also recorded in Lincoln ( note the vertical, rather than horizontal waterfall screen)

Also recorded in Loughboro’

April is now with us and as well as several minor showers there is the Lyrid shower to look forward to over the 21/22 of the month , peak 11:00 – 22:00 BST on 22nd April. Moon in its first quarter should not cause any problems and for Lunar observers the Lunar X and V are at peak visibility around 21:40 BST on sun22 April.

 

clear skies

 

Pete H