Observing comet 46P/Wirtanen

Date: 05./06.12.2018
Time: 23:00
Observing site: Preiviiki, Pori, Finland
Instrument: N250/1200 mm

NELM: 5.4
SQM: 20.65
Darkness of the background sky: 3
Seeing: –
Transparency: –
Weather: clear sky, fresh western wind, no Moon, no snow, +3 C

Objects observed: comet 46P/Wirtanen

Finally I was able to observe comet 46P/Wirtanen after several unsuccessfull attempts! I had been searching the comat for a couple of times before this, but then I realized, that I had been looking for in in a wrong place! I realized, that I hadn’t updated the orbital elements of the comet to my Skymap Pro, and because the orbits of comet change from perihelion to perihelion, my orbital elements were outdated. But after updating them, I was finally able to locate the comet!

In the before Finnish independence day (6th of December) me and couple of other active members of Porin Karhunvartijat went to Preiviiki, a couple of kilometers west from Pori city to observe the comet and also some other objects.

Weather during this observing session was windy and quite chilly! In the beginning of the session it was cloudy, but luckily the clouds went away, and we were able to observe this much anticipated comet!

The comet was easy to find, and it was barely visible also with naked eye with averted vision. The comet was clearly visible in the finderscope as a fuzzy, round object. In the ocular (with 38x magnification), the comet still looked like a fuzzy, round object, with very hazy, undefined outer edge. So only the coma of the comet was visible, there wasn’t any sign of visual tail. There was a central brightening in the middle of the coma, but no other features were visible. The comet looked pretty much what I had expected and did not offer many surprises, at least no visually.

In this case the comet was interesting also because it passed Earth at very close distance, only 0,08 AU! It is not very usual for a comet to come this close to Earth! Luckily it passed Earth safely, and it just provided some fun cometgazing for astronomy enthusiasts! Comet 46P/Wirtanen was found by American astronomer Carl A. Wirtanen in 17th of January 1948. This comet is very interesting for Finnish amateur astronomers also because the founder of comet is of Finnish ancestry and the comet has Finnish name! The founder of comet, Carl A. Wirtanen discovered several comets and minor planets during his career in Lick Observatory in California, USA.

Picture 1. Comet 46P/Wirtanen observed with 10” Newton in 5./6.12.2018 in Preiviiki, Pori, Finland.

Observing Comet C/2013 US10 (Catalina)

Date: 23./24.12.2015
Time: 07:15-07:50
Observing site: Friitala, Ulvila, Finland
Instrument: 10×50 binoculars, L80/400mm (4” refractor)

NELM: 5.0
SQM: –
Darkness of the background sky: 5
Seeing: –
Transparency: –
Weather: Clear sky, full Moon setting in NW, light sky, twilight at the end of the observing session, very mild weather, no snow

Objects observed: C/2013 US10 (Catalina)

Finally also I was able to observe the anticipated comet C/2013 US10 (Catalina). I was observing the comet in Friitala, Ulvila, Finland in the morning of Christmas eve.

I was able to locate the comet easily just 12 degrees south of Arcturus. With my 10×50 binoculars, the comet appeared as small, fuzzy star with a little bit brighter core. There was no tail visible visually. With the binos, I estimated that the size of the coma of the comet was about 3,3′ (estimated with the separation of stars A and B in picture 1) and brightness about 6,2 magnitudes (estimated with out of focus -method).

I observed the comet also with my 3” rich field refractor. With this instrument, the comet appeared also as a small fuzzy nebulous spot that looked like many unresolved globular clusters with this instrument. There was no tail visible with this instrument either. With the refractor, I estimated that the degree of condensation of the coma was 6, and size about 4,6′(estimated with the separation of stars A and B in picture 2).

The comet was easy with the binoculars, but ideally it should be observed with larger instrument, perhaps with about 4” refractor or reflector.

Picture 1. Comet C/2013 US10 (Catalina) observed with 10×50 binoculars.
Picture 2. Comet C/2013 US10 (Catalina) observed with 3” refractor.



Comet Lovejoy observed in harsh winter conditions

Date: 11./12.1.2015
Time: 18:00-18:30
Observing site: Kurkijärvi, Kuusamo, Finland
Instrument: L102/1200mm (4” refractor)

NELM: 5.7
SQM: 20.50
Darkness of the background sky: 3
Seeing: 2
Transparency: 3
Weather: Mostly clear but somewhat hazy sky, cold breeze, -20 C

Objects observed: C/2014 Q2 (Lovejoy)

Comet C/2014 Q2 (Lovejoy) is now well visible in the night sky of Northern hemisphere. The comet is now dwelling in the constellation of Taurus, where it can be seen as a fuzzy 4th magnitude star with naked eye! Yesterday evening I went to observe this icy nomad by myself.

I was observing the comet with my 4” refractor. With my instrument, the comet appeared as a round, fuzzy ball of light. In the coma of the comet, there is a clear central brightening. The coma is getting gradually brighter towards the center. There is no visual tail visble with the comet. The apparent diameter of the coma of the comet is about 21′. The degree of condensation of the comet is about 6 in the scale from 0 to 9.

Degree of condensation is just a way to describe how the light of the comet is distrubuted in the object. If degree of condensation is very low, then the brightness distribution is very even, but if degree of condensation is high, then the coma of the comet is almost stellar in appearance.

I was also able to observe the comet with naked eye. With naked eye it appeared as a fuzzy, 4th magnitude star in the constellation of Taurus.

Comet Lovejoy observed with 4'' refractor.
Comet Lovejoy observed with 4” refractor.

Comet Jaqcues and a planetary nebula

Date: 23./24.8.2014
Time: 23:30-01:20
Observing site: Tähtikallio observatory, Finland
Instrument: C416/4064mm (16” Meade)

NELM: 5.3
SQM: 21.00
Darkness of the background sky: 3
Seeing: 2
Transparency: 3
Weather: Some haze in the sky, occasional clouds, calm, no Moon, pretty warm

Objects observed: C/2014 E2 (Jaqcues), NGC 6905

During the night between 23rd and 24th of August 2014 I had an opportunity to do some observing with the large telescopes of Tähtikallio Observatory, Finland. This time I was observing with the 16” Meade of Tähtikallio observatory. The targets that I observed were comet Jaqcues and planetary nebula NGC 6905.

Comet Jaqcues was visible as a round and fuzzy object. In the middle of the coma, there was a rather starlike central brightening. The brightness of the coma decreased gradually outwards. The visual diameter of the coma was about 5′. No tail was visible visually.

Comet Jaqcues observed with 16'' Catadioptric.
Comet Jaqcues observed with 16” Catadioptric.

NGC 6905 is a planetary nebula in constellation of Delphinus, the Dolphin. The nebula is know as the Blue Flash -Nebula. I made following notes of my observation:

@101x: small, round fuzzy spot, no details. @270x: oval-shaped nebula, long axis SW-NE -oriented. Central star visible with averted vision. Visual size roughly 1,6’x1,3′. The eastern part of the nebula seems to be brighter than other parts of the nebula.

NGC 6905 observed with 16'' Catadioptric.
NGC 6905 observed with 16” Catadioptric.

Weather during the night wasn’t optimal, there was some haze in the sky, and the sky wasn’t completely dark yet. Besides this, there were some occasional clouds moving across the sky. Eventually these clouds forced me to stop observing after I had barely finished observing NGC 6905.

Observing comet Lovejoy

Date: 30.11/1.12.2013
Time: 20:00-21:10
Observing site: Uittamo, Turku, Finland
Instrument: L102/1000mm

NELM: 5.3
SQM: 19.51
Darkness of the background sky: 4
Seeing: 2
Transparency: 1
Weather: Clear sky, -6 °C, calm, no Moon, no aurorae

Objects observed: C/2013 R1 (Lovejoy), R Lyr, mu Cep, rho Cas, Psi 1 Aur, eta Gem

Unfortunately comet ISON didn’t survive it’s close contact with our Sun, and now all that is left of it is just pile of gravel and sand! So ISON is officially dead now, R.I.P. ISON!

But whereas ISON might be dead, there’s another great comet visible in the northern sky! This comet hasn’t got as much media attention as ISON did, but it easily equals comet PanStarrs from spring 2013! This comet is comet C/2013 R1 (Lovejoy), and it’s well visible from northern latitudes, especially in morning sky!

I observed comet Lovejoy during the night between 30.11/1.12.2013 in Uittamo district of Turku. The comet was at low altitude (altitude only 13º), but I could still easily locate it with my humble 7×18 binoculars. With my small binos, the comet appeared as a dim, fuzzy “nebula”. I observed it properly with my 4” refractor @25x. The coma of the comet appeared as a round and diffuse “nebula” and there is a distinct central brightening in the center of the coma. The tail of the comet is excessively faint, and it is only visible with averted vision and sweeping. The tail is pointing to position angle ~340º. The length of the tail that was visually visible in these conditions was about 15′. Degree of condensation of the comet is about 7.

Lovejoy is already a fine comet easily visible with modest amateur instruments, so it’s worth of your attention! I’ll later write a post about how to find comet Lovejy!

Comet C/2013 R1 (Lovejoy) in 30.11./1.12.2013
Comet C/2013 R1 (Lovejoy) in 30.11./1.12.2013

November things

November 2013 is soon over, and I haven’t made any post to this blog during this month. So I thought, that I’ll make this post to summary few thoughts about this November from astronomical point of view.

Few words about observing conditions: mostly this November seemed to be quite a crappy month, it has been mostly cloudy, but there has also been few sunny days and also some clear nights! In November, we had some random snow showers in 24th of November. That day it was cold and very windy, and we had some isolated snow showers. Albeit the snow showers, much of snow didn’t pile up on the ground. After that day, there was an extremely thin and discontinuous layer of snow, but it all melted away after two days, when it was raining.

And then something about observations: in November 2013, I made 52 variable star observations, which is one more than in October! This is very surprising fact, considering the poor observing conditions during November! In November, I made also my personal observing activity record of this year, during this month I made more observations than ever before this year!

In november I didn’t do much other observing besides variable star observing. Nevertheless, I observed and sketched comet C/2013 R1 (Lovejoy) in the last night of November (31.11./1.12.2013).

Comet ISON appears to be disintegrated at least to some extent. Currentlt the condition of the comet is still unclear, but I’m sure we will know more in the first days of December. I haven’t been able to observe the comet so far, but I will try to observe it in December, if it hasn’t disintegrated totally!

So, that was November 2013, and only one month of this year is remaining..I’m expecting that month to be really interesting astronomically!

Observing in Ulvila observatory 31.3.-1.4.2013

Date: 31.3./1.4.2013
Time: 19:00-21:00
Observing site: Ulvila observatory, Finland
Instrument: C280/2750mm (11” Catadioptric)

NELM: 5,7
SQM: 20,28
Darkness of the background sky: 4
Seeing: 2
Transparency: 2
Weather: Clear sky, -2 °C, calm, snow still on the ground, faint aurora arc in the northern sky at low altitude

Objects observed: Comet C/2011 L4 (PanSTARRS) (visual, sketching), NGC 5053 (visual, sketching), NGC 5466 (visual, sketching), SS Cyg (visual), R Cyg (visual)

When March was turning to April, I was doing some observing in Ulvila observatory, Finland. This time I observed comet C/2011 L4 (PanSTARRS), NGC 5466, NGC 5053, SS Cyg and R Cyg. Observing conditions were OK, it’s not very cold anymore, the temperature was only 2 °C below zero. The nights are though getting shorter already, and the beginnig of the summer time means that the observing sessions are now starting even later.

The comet C/2011 L4 (PanSTARRS) was still visible, and it was now approaching the Andromeda galaxy. During this night, the apparent distance between the comet and the galaxy was less than 3º. I observed the comet with the large binoculars of Ulvila observatory (25×100), the binoculars have a FOV of 2º. The comet itself fitted in nicely in the field, but I wasn’t able to see both the comet and the galaxy in the same field. The comet wasn’t anymore visible with naked eye, but it was easy to see with the binos. The length of the tail seems to be about 45′ and it is pointing to position angle 340º. The coma is still very condensated, the DC is 8, the diameter of the coma is about 3′.

Comet C/2011 L4 (PanSTARRS) 31.3./1.4.2013
Comet C/2011 L4 (PanSTARRS) 31.3./1.4.2013

Besides observing and sketching the comet, I did also some deep sky -sketching. This time I observed and scketched globular clusters NGC 5466 and 5053. NGC 5466 appeared as a round, faint and fuzzy nebula. The cluster has pretty even brightness distribution. The cluster appeared to be granulated, some individual stars were also resolved.

NGC 5466 observed with 11'' Catadioptric
NGC 5466 observed with 11” Catadioptric

NGC 5053 appeared as a very faint and vague nebula, which was visible only with sweeping and averted vision. No hope of resolving any stars. I think this should have been visible better with my instrument, but the poor background sky darkness could explain the fact that it was visible only barely.

NGC 5053 observed with 11'' Catadioptric
NGC 5053 observed with 11” Catadioptric

After having done some deep sky -sketching, I observed also variable stars SS Cyg and R Cyg. Both stars are in their minimum brightness now, SS Cyg about 12.0, and actually I couldn’t even see R Cyg, so I made a negative observation of it, the magnitude of the star was <14.0.

Variable star observations:

Date Time Star Mag. Comp.
31.3./1.4.2013 02.53 SS Cyg 12.0 10.9/11.9
31.3./1.4.2013 03.12 R Cyg <14.0 14.0