Skip to main content

ASASSN-17hx Nova in Scutum

23 posts / 0 new
Last post
GKI
GKI's picture
ASASSN-17hx Nova in Scutum

Hi all, I see from my twitter feed that this nova was discovered on June 23rd last, now being reported as magnitude 8.8 unfiltered. 

http://www.cbat.eps.harvard.edu/unconf/followups/J18314588-1418559.html

http://www.skyandtelescope.com/observing/sky-surprises-new-comet-c2017-o...

it seems to be slowly rising in brightness, my apologies if this had been covered already. 

Keith..

 

 

 

SET
SET's picture
Nova in Scutum

Is there a VSP chart available yet to make observations of this nova?

 

Chris Stephan   SET

Deconinck Michel
Deconinck Michel's picture
Sure, use the  name ASASSN

Sure, use the  name ASASSN-17HX in  https://www.aavso.org/apps/vsp/

I visually estimated this star since end June, that was not easy because of the rich field in this Milky Way area but now the magnitude helps.

Clear sky to you all

Michel

BRJ
BRJ's picture
Nova Sct 2017

I find the lightcurve of Nv Sct '17 so far to be most interesting. Unquestionably, it belongs to the class of slow novae, by far the most unpredictable in behavior, subject to erratic variability and for visual observers the most "entertaining" of all the nova types in my book. While probably still a bit early to conjecture Nv Sct '17 future, I might speculate that so far its lightcurve is suggestive of a class J nova (per Sterope, Schaefer & Hendren). Rather similar early behavior was displayed by V723 Cas and HR Del in the past. If indeed similar, the star might remain reasonably near maximum brightness, while perhaps subject to striking fluctuations, all the way until it nears solar conjunction...or possibly even longer!

J.Bortle (BRJ)

 

BRJ
BRJ's picture
Nova SCT 2017 Re-Brightening

I'm rather surprised to find no one has mentioned this nova's dramatic re-brightening which has taken place over the past 50 or 60 hours. Although having faded from its 8.5 brilliance at maximum in the very last days of July to a magnitude of 11.0 to 11.2 by August 25th and oddly plateauing there until three nights ago, the nova is now experiencing a major re-brightening! Last evening before moonrise (Sept 10.0535UT) I recorded it as 9.5 magnitude and judging from the LCG's plot it would appear to still be on the rising leg of the re-brightening. Certainly a peculiar animal this one!

J.Bortle   (BRJ)

 

SGQ
SGQ's picture
Nova SCT 2017 Re-Brightening

It is brighter than 9.0 now.Worth to be followed with new enthousiasm! It is the first observation after 6 days of clouds and rain here in Rome: a great difference immediately noticed.

hambsch
hambsch's picture
Brighter nova

Indeed I also saw it much brighter the past nights. Data are private for the moment.

Josch

RZD
RZD's picture
Nova SCT 2017 Re-Brightening

OBJECT                DATE          MAG         
--------  ------------  ---------  -----  --  ---  ---
ASASSN-17HX 20170911.855   8.90V

OBS: Diego Rodriguez-Guadarrama Observatory
TEL: LX200 0.25-m f/6.3 Schmidt-Cassegrain
CCD: ST8XME

 

BRJ
BRJ's picture
Nova Sct 2017

The lack of posts here commenting on this highly active nova's behavior continues to surprise me, as currently I regard it as probably the most interesting object in the sky, given how it is performing. Last evening I noted the definite beginning stages of yet another rebrightening of the nova...its second following the nova's primary peak back in the final days of July.

I note the distinct similarity of Nova Sct rather uncommon lightcurve to that exhibited by the recent naked eye nova visible in Sgr just two years ago. That one, V5667 Sgr, also displayed multiple dramatic rebrightenings, ultimately followed by a 6 magnitude "dust dip". Now if Nova Sct follows the same pattern, then we might anticipate a couple more rebrightenings to around magnitude 9.0 as it descends into the western sky. Then, as Sct approaches the evening twilight, or just as it enters it, we might witness a dust dip in its lightcurve, too.

John Bortle    (BRJ)

 

TCB168
TCB168's picture
Nova Sct 2017 also

I agree that it is very interesting.

There is plenty of interest in the spectroscopy community with large numbers of impressive spectra being produced.

see http://www.astrosurf.com/aras/Aras_DataBase/Novae/2017_NovaSct2017.htm

I think it needs continuing intensive monitoring.

My only other comment is that there seems to be a large scatter in the CCD measurements. I'm not sure why as there is a good selection of comp stars availble.

Terry

 

Deconinck Michel
Deconinck Michel's picture
Nova Sct - Spectro and CCD

Hi Terry Thank you for the specto link, for me (as visual observer) the issue with this large collection is the lack of summary or associated scientific info,... yet. 

For the second point, as already mensionned by John, you'r completely right.  I send a message to this CCD observer which report those long vertical green ladders and some far out of the curve CCD observations but I don't got any answer. I did also push on the button "report discrepancy" of the new enhanced LCG but saw no action... Anyway the very last observations of this observer looks better.

To avoid this large scatter, I only request the pure visual estimations while asking the curve.  look at the attached file.  But doing this I take off also the good V CCD observations.

Michel

File upload: 
PYG
PYG's picture
Re: asassn-17hx

The transition phase (if/when it occurs) is always the most interesting stage of a Nova light curve for observers.  Like John, I'm a bit surprised that people have been a bit quiet about it's activity of late!

Gary

luckas
Information

Hi Michael,

Several linked ATels on developing phenomena can be found here:

http://www.astronomerstelegram.org/?read=10737

Detailed anlaysis including notes by Prof. Steve Shore in the ARAS Eruptive Stars monthly:

http://www.astrosurf.com/aras/novae/InformationLetter/ARAS_EruptiveStars...

Paul

Deconinck Michel
Deconinck Michel's picture
Thank you Paul much

Thank you Paul much appreciated !

Michel

lmk
lmk's picture
What a strange object!

The last ATEL is almost a month old! It showed a classic Fe-II nova-like spectrum, but the lightcurve is so odd, the double maximum. GK Per-like oscillations??

Mike

FJQ
FJQ's picture
Fe lines in Asassn-17hx

To:  Mike,

RE:"... It showed a classic Fe-II nova-like spectrum ..."    Yea they were strongly shown in a LISA spectra I took with my 13" telescope from Mt. Pinos in August & Sept; see:

http://astroimage.info/spectra/asassn-17hx_%2020170827_234_James%20R.%20Foster.png

http://astroimage.info/spectra/asassn-17hx_20170923_162_James%20R.%20Foster.png

James

 

BRJ
BRJ's picture
NOVA SCT 2017 RE-BRIGHTENING

I would note that Nova Sct '17 has begun its third re-brightening in the course of the past 50 or so days. The light curve of the nova resembles very few other previous novae whose light curves I've found in the literature, especially considering the amplitude of its re-brightenings particularly the first one. Unfortunately for me, the nova will pass behind some local obstructions in less than another month, preventing my following this very interesting object further. I'm particularly interested to see if this nova exhibits a "dust dip" prior to fading into the evening twilight.

J.Bortle   (BRJ)

 

lmk
lmk's picture
Yes it is! I just estimated

Yes it is! I just estimated it visually at 9.7, so this rebrightening now, is significantly larger than the one 3 weeks ago.

Mike

Deconinck Michel
Deconinck Michel's picture
Exact

Exact, I just estimated this exotic nova yesterday Oct 21.76, magn: 9.75, pefrectly in line with your observation.

Suspence for tonight !

Michel

BRJ
BRJ's picture
Nova SCT 2017

Following its recent third re-brightening which peaked near 9.0 on the 24th or 25th of October, the nova has exhibited a steady decrease in brightness which as of this morning (November 12th) has brought it down to magnitude 11.5 the faintest point it's been at in several months. Showing no sign of hesitation in this decline so far, I wonder if this may be the beginning of a "dust dip" which I've mentioned several times previously in this thread? The next week, or two, of the nova's brightness behavior could prove very interesting.

J.Bortle

 

lmk
lmk's picture
Actually, the last couple

Actually, the last couple days, observations are coming in between 11.5 and 11.0, some of this could be due to measurement error, but maybe it has stopped declining, and entered a new oscillatory phase, or re-brightening? My latest obs from last night is at 11.0

Mike

dedricksond
ASASSN-17hx

Hi,

When I look at the light curve I keep thinking of this star as the Roller Coaster nova.

Duane

BRJ
BRJ's picture
NovaSCT 2017

You are quite correct, Mike. No sooner had I posted the other day that it seemed as if the nova was finally going to decline into a "dust dip" its brightness turned around and began to rise toward yet another re-brightening peak!. As of this morning, reports indicated it had attained magbitude 10.0 and was still rising. Anyway, it's beyond any further observation for me now, having descended below my treeline in the southwest until next season.

J.Bortle   (BRJ)

 

Log in to post comments
AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484