Archive for the ‘Astronomy, Science’ Category

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.

Another peak for V1369 Cen

January 8, 2014

I just came inside after making another visual estimate of V1369 Centauri. The roller-coaster of the nova continues as shown by the updated light curve.

V1369CenJan92013

 Click on the image to enlarge it. My several observations are in purple as usual.

The nova in Centaurus from Stockport

January 5, 2014

I spent last night at a really well-attended ASSA member’s night at Stockport Observatory last night, an awesome start for 2014.

A number of members enjoyed views of the nova in Centaurus (V1369 Cen). The cross hairs in the light curve below are over my visual estimate just after 1am; as in previous posts, the observations in purple show others I’ve made (only 5 up to this point).

V1369CenJan52013

The details of the observation are as follows:

V1369 Cen Obs Details Jan 5

When I first submitted the observation to AAVSO at around 3am, it was around 0.3 magnitudes brighter than the previous one. Others have since submitted more observations around the same time with similar magnitude values.

The nova was clearly visible to the unaided eye from Stockport at that time, as were the 4.7 and 4.3 comparison stars I used for the estimate (shown, by the conventional labels, as 43 and 47 above).

An observation a couple hours earlier at around 10:30pm when the nova was closer to the horizon was around 4.8 but I was a little uncertain of the estimate due to the low altitude so I didn’t submit that one to AAVSO.

Will the current rise continue past the last peak? The only way to find out is to keep watching!

I also made visual estimates of the Classical Cepheid l Carinae and LBV (Luminous Blue Variable) η Carinae. I had aimed to make estimates of others (R Carinae and V Puppis) but didn’t quite get there. I was too busy having a good time looking at other objects through my Meade LX-90 ‘scope and sharing views with ASSA members.

V1369 fading again

December 30, 2013

I made a visual estimate of magnitude 4.4 of the nova overnight. Subsequent observations show that it has dropped further since.

Here is the updated light curve:

V1369CenDec302013

The observation under the cross-hairs is my last (magnitude 4.4) observation and the others in purple (click image to enlarge) are the estimates I’ve submitted to AAVSO so far. 

Sebastian Otero’s latest forum reply asks whether the current fading will be the nova’s last one and suggests possibly not, given its erratic behaviour so far.

V1369 light curve update

December 28, 2013

I just made an estimate of V1369 Cen (at about 2am on Dec 29) at magnitude 4.3. It may actually be closer to 4.2 but I could not convince myself of that with respect to nearby magnitude 4.0 and 4.3 comparison stars. Visual and Johnson V observations are shown below (via VStar), with my estimate in the cross-hairs and a polynomial fit (in red) to make the outline of the light curve more obvious.

V1369CenDec292013

Regarding the polynomial fit, bear in mind of course George E.P. Box’s maxim that:

Essentially, all models are wrong, but some are useful.

So far, 628 observations have been submitted to AAVSO. Of these, 214 are visual observations.

What a fascinating, meandering, unpredictable progression. I’ll try to monitor this nova as much as possible over the next week, while still on holidays.


Follow

Get every new post delivered to your Inbox.

Join 70 other followers