Archive for the ‘Astronomy, Science’ Category

Another Nova Sgr 2015 No. 2 update

March 30, 2015

I’ve made 10 observations of the nova since March 19, mostly visual, 3 DSLR, one of which has yet to be processed.

The (rather noisy) light curve is starting to show the kind of early oscillations that seem to be common in novae and certainly the last two bright novae I’ve seen. The red fit “line” helps to make this more obvious.

LC-and-20-degree-polyfit-2015-03-31

The cross-hairs are over my most recent observation early this morning.

Nova Sgr 2015 No. 2 update

March 25, 2015

I made visual and DSLR photometric observations of the nova on March 21 and 22. The image below shows the nova before sunrise on March 22.

NovaSgr2015_2_Mar22-arrowed

The light curve shows my most recent submission under the cross hairs.

LC-2015-03-25

 

It appears that the nova has peaked but these objects are unpredictable so we may see some fluctuations yet. The local weather has made observations difficult for the last 3 days.

Nova Sgr 2015: first observation

March 19, 2015

The conditions at 6am today were not ideal: lots of intermittent cloud, or more accurately, intermittent gaps.

I estimated the nova to be at magnitude 4.9. It was substantially brighter than the 53 comparison star and may even have been brighter than the 47 comparison star (AAVSO chart ID 14582KC).

NovaSgr2015-2015-03-20

I marked the observation as “uncertain” (comment code Z on WebObs) and added the comment:

7×50 binoculars;AT LEAST mag 4.9;may have actually been brighter than 47 comp;intermittent cloud

Tomorrow morning, whether permitting, a brighter comparison star may be needed assuming this thing keeps brightening. Getting up early enough to make a DSLR observation would be nice too.

 

 

Nova Sgr 2015

March 18, 2015

There’s a bright nova in Sagittarius (PNV J18365700-2855420 where PNV = possible nova candidate, its discovery designation).

Like the last bright southern nova (Nova Cen 2013), this one was also discovered by John Seach in NSW.

The nova was discovered on March 15 so it’s early days yet. There are 35 observations in the AAVSO International Database.

NovaSgr2015-2015-03-19

I tried to get out to observe it this morning but it was cloudy. When the weather clears I’ll make visual and time-permitting, DSLR observations.

First V1369 Cen estimate for several days

February 16, 2014

It’s been cloudy here for several days and before tonight, my last estimate of V1369 Centauri was on Feb 10 at magnitude 6.2.

V1369CenFeb162014

My latest visual estimate tonight (under the cross-hairs above) was magnitude 6.55, with 6.5 and 6.6 comparison stars.

V1369 Cen light curve update

February 10, 2014

Here’s an updated light curve for the nova:

V1369Cen11Feb2014

My visual estimates are in purple (click the image to enlarge it) and the cross-hairs are over my latest observation. The polynomial fit (degree 30) highlights the overall shape of the light curve. Only visual and Johnson V observations are shown.

V1369 Centauri Light Curve update

February 4, 2014

My latest visual estimate of the nova is magnitude 6.0 (with comparison stars 6.0 and 6.1). Here’s the latest V and visual light curve.

V1369CenFeb52013

The overall fading trend continues with some oscillations. The latest VSS newsletter has some interesting articles about the nova.

V1369 Cen update

January 27, 2014

The nova is gradually on the way down, but it’s certainly not smooth. Here’s the latest light curve.

V1369CenJan272013

The cross-hair is on my latest visual estimate (5.85). Rob Jenkins (a fellow ASSA member) made a photometric observation (5.932, Johnson V) a couple of hours later. Subsequent visual estimates suggest the nova has brightened a little again.

V1369 Cen light curve update

January 19, 2014

The overall decline continues with intermediate rises and falls. Tonight I estimated the nova at magnitude, 5.5 bracketed by 5.4 and 5.6 comparison stars.

V1369CenJan192013

The polynomial fit (in red) shows the essential shape of the light curve and overall downward trend.

V1369 Cen faded since Jan 8, rising again

January 12, 2014

I was away for 3 days but tonight have estimated V1369 Cen at magnitude 4.9, compared to 4.5 on January 8th.

V1369CenJan122013

Despite an apparent rise again now, the “sawtooth” pattern of peaks appears to be showing an overall downward trend. I wonder whether that will that continue.


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