New Nova?

[Merlin66]

Just received this advice:

PNV J11261220-6531086 (N)

RA 11h26m15.30s, DEC -65°31'26.3" (J2000.0; Daniel Bamberger)
2018 Jan. 14.4861 UT, V= 7.0 mag
Discoverer: Rob Kaufman, Bright, Victoria, Australia

Follow-up reports:
http://www.cbat.eps.harvard.edu/unconf/followups/J11261220-6531086.html

Well done Rob!

(EDIT: this position is near HD99438 (mag 7) and TYC 8980-203-1 (mag 11.13) in Musca)

[Tropo-Bob]

Well done Rob and thanks for the post Ken.

I was just wishing yesterday for a new comet or nova!

[Rob_K]

Thanks Ken, Bob! Still needs additional spectroscopic confirmation, beyond what I managed to get last night. Here's my discovery image and the low-res spectrum I got.

Cheers -

[Merlin66]

Rob,
Subject to weather I'll see if I can get a spectrum tonight.

[PeterM]

Congratulations and well done Rob.

[bigjoe]

Bravo!:thumbsup:
bigjoe.

[Merlin66]

Rob,
Interesting that they say it erupted around the 1st or 2nd....The formation of the prominent Fe "Iron Curtain" certainly infers it's a "FeII" nova (See Gray & Corbally Stellar Spectral Classification, p487 and Steve Shore's ARAS notes)

[Rob_K]

All official now, CBET 4472 Nova Muscae 2018 has just been issued! Would love to get the text but it’s behind a paywall.

Cheers -

[Merlin66]

Well done Rob!
I remember another Nova Muscae back in the 80's when we (ASV Photographic Section) had pre-discovery images - but they were not checked before Liller notified the IAU......

[Merlin66]

AAVSO have published:


AAVSO Alert Notice 609
Nova Muscae 2018 - PNV J11261220-6531086
January 15, 2018

Event: Nova in Musca - Nova Muscae 2018 = PNV J11261220-6531086

Discovered by: Rob Kaufman (Bright, Victoria, Australia)

Discovery magnitude: 7.0 V (on four frames, using Canon 650D and 55mm lens)

Discovery date: 2018 January 14.4861 UT

Coordinates (2000.0): R.A. 11 26 15.16 Decl. -65 31 23.3
Position from VSX; measured by Daniel Bamberger (Marburg, Germany) on frames taken by Robert Fidrich (Bakonycsernye, Hungary).

Spectra: Low-resolution spectroscopy indicating that PNV J11261220-6531086 is an FeII-type classical nova was obtained by Rob Kaufman on 2018 January 14.6035 UT. His spectrum is here:
http://i727.photobucket.com/albums/ww271/Rob_Kau/PNV%20J11261220-6531086%20spectrum%2014%20Jan%20201 8%20text.jpg~original

Observing recommendations: Observations of all types (visual, CCD, DSLR, spectroscopy) and multiple bands (BVI in particular) as instrumentation permits are strongly encouraged as the nova evolves.

Observations reported to the AAVSO:
2018 Jan. 14.92620 UT, 6.714 TG +/-0.012 (D. Blane, Henley-on-Klip, South Africa);
15.19700, 6.85 (S. Otero, Buenos Aires, Argentina; visual obs);
15.3887, 6.5: V (J. Hambsch, Mol Belgium; image overexposed);
15.3887, 7.1: B (Hambsch; image overexposed);
15.51, 6.60 V (A. Henden, AAVSOnet BSM_S data; V obs nearly saturated);
15.51, 7.10 V (Henden, AAVSOnet BSM_S data);
15.54372, 6.7 (D. Benn, Klemzig, S. Australia);
15.57, 6.3: R (E. Guido and A. Noschese, remotely using iTelescope Observatory, Siding Spring; via TOCP);
15.57932, 6.974 V +/-0.001 (A. Pearce, Nedlands, W. Australia);
15.67277, 7.507 B +/-0.002 (Pearce);
15.71, 7.4: V (A. Valvasori, Siding Spring; via CBET 4472);

Charts: Charts with a comparison star sequence for PNV J11261220-6531086 may be created using the AAVSO Variable Star Plotter (VSP). Observers are cautioned that there is a magnitude 15.2 star 6" to the S. The name Nova Mus 2018 is being added to VSX; once it has been added, charts may be made using that name.

Submit observations: Please submit observations to the AAVSO International Database using the name PNV J11261220-6531086. The name Nova Mus 2018 is being added to VSX; once it has been added, observations should be submitted using that name. Once a formal GCVS name is announced in an IAU Circular or CBET, please use that name.

Notes:
a. Designated PNV J11261220-6531086 when posted to the IAU Central Bureau for Astronomical Telegrams Transient Object Confirmation Page (TOCP). Unless otherwise noted and except for observations reported to the AAVSO, the information in this Alert Notice is taken from IAU CBET 4472.

b. P. Schmeer (Saarbrücken-Bischmisheim, Germany) reports that according to ASAS-SN Sky Patrol observations (Shappee et al. 2014ApJ...788...48S and Kochanek et al. 2017PASP..129j4502K) and using the position determined by Bamberger, this nova eruption apparently began between 2018 January 1.25 and 3.24 UT (maximum brightness V = 8.8 mag on Jan. 3.24 UT): https://asas-sn.osu.edu/light_curves/87fd7dc5-af64-42aa-9f2e-59b05de938f9

d. Position end figures
- R. Kaufman (2018 January 14.4861 UT; discovery image): 12.20s, 08.6"
- E. Guido and A. Noschese (iTelescope Observatory, Siding Spring, 2018 Jan. 15.57 UT): 14.95s, 24.1".
- A. Valvasori (2018 Jan. 15.71 UT): 14.94s, 24.9"

e. P. Schmeer reports a Gaia DR1 source (G = 18.02 mag) is located 1.3" from Bamberger's position. Also, S. Otero (Buenos Aires, Argentina) in VSX identifies star Gaia DR1 5237407060614222336 (G = 18.0) at 11 26 15.00 -65 31 24.2 (2015.0) as a likely counterpart. He notes that the area is crowded.

f. Images
- R. Kaufman (Bright, VIC, Australia, 2018 Jan. 14.4861 UT; discovery image): http://i727.photobucket.com/albums/ww271/Rob_Kau/PNV%20J11261220-6531086%2014%20Jan%202018%20crop%20 text.jpg
- E. Guido and A. Noschese (iTelescope Observatory, Siding Spring, 2018 Jan. 15.57 UT): http://bit.ly/2DhOSKp
-A. Valvasori (2018 Jan. 15.71 UT): https://flic.kr/p/228Xp46

g. Animation by E. Guido and A. Noschese (2018 Jan. 15.57 UT), comparing their image above with archive POSS2/UKSTU Red plate (1998-03-19): http://bit.ly/2mHn353

Congratulations to Rob Kaufman on his latest discovery!

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.

[Rob_K]

Haha, time is of the essence! Took me ages to do all the necessary checks, get rough astrometry, estimate magnitude etc. I filled out the TOCP form and was about to hit the send button - but it still seemed too good to be true! So I dragged the camera out to the backyard again, sighted the nova for a spectrum, took aa ambit 30 sec exposure, looked at it and immediately saw the bright H-alpha & H-beta emissions. I practically ran back inside and hit the send button!

Cheers -

[beren]

Congrats Rob ,great work :thumbsup:

[Terry B]

I took a spectrum and photometry of this nova last night.
V= 6.72
B= 7.21
The spectrum is from the Ha region and demonstrated a broad Ha emission with an expansion velocity over 1200km/s

[Merlin66]

Well done mate!
I see it also made an ATEL #11183

I hope to have similar results tonight...

[PeterM]

You should have a nice surprise in your PM this morning...CBET 4472 was amended (minor changes) and a new CBET 4473 released.
When a professional astronomer who has been studying variables for 40 yrs notes in her email "very interesting object" then you know ya dun good!...again congrats Rob.

[Merlin66]

Nova Musca 2018 - Ha region spectrum from last night.
(Not my best - issues with guiding, but shows the prominent features)

[Rob_K]

Great job on the spectra Terry and Ken. I’ve taken spectra the last 2 nights and notice that the H-alpha emission is quite broad - I’ll process them when I get home.



Thanks so much for your help Peter, yes, you hope that anything you discover is of interest scientifically as there’s little point in discovering things otherwise! My greatest regret in astronomy revolves around the last outburst of recurrent nova V745 Sco in 2014. I had monitored it for years and one morning while I was away on work I photographed the field and raced back to my motel to look at the results. Right on the nova position there appeared to be an extremely faint star. But I was very busy and had a big day ahead of me out in the bush, so I convinced myself that it was probably just an artifact. Just seemed too much time and trouble to properly process it and put out appropriate alerts. A day-&-a half later Rod Stubbings announced the discovery of V745 Sco at mag 9. If only I had reported that it could possibly be rising, think of the additional valuable data that could have been obtained!

Cheers -

[silv]

Congratulations Rob! And thanks a lot for sharing the small personal stories on your 2 discoveries. :) :)

Can someone enlighten me about the date/time format?
"2018 January 14.6035 UT "

My guess is that it stands for
UTC January 14th at second 6035 - which is around 1:40 AM ?

[Terry B]

It is just decimal of a day ie 0.6035 of 24 hrs
= 14.485hrs
= 14hrs 29.16mins
UT starts at midday so about 2:30am on Jan 15 London time.

[skysurfer]

Midday at 2:30 ? Weird timezone. Probably North Korea.
In Australia it is midday at 01:00 London time in summer and 03:00 in winter when London has DST.

[Terry B]

Whoops. Yes I’m wrong. I was thinking of JD and they start at UT 12.

[Rob_K]

I've got tons of data to process but here's first-cab-off-the-rank, low-resolution optical spectrum of Nova Muscae 2018, 16 Jan 2018 (last Tuesday night).

Cheers -

[Merlin66]

Rob,
Your results confirm once again the excellent capabilities of using a SA100 objective grating with a standard lens DSLR combo.
Keep them coming....

[silv]

Thank you both, Terry and Skysurfer.

Took me quite a while to get it... 2 hours actually! :o

@Terry: "Yes I’m wrong. I was thinking of JD and they start at UT 12."

I had skipped that bit because I didn't know what "JD" stands for and hoped / assumed Terry and Skysurfer were merely talking about a mix up in time zones which didn't really have an effect on Terry's previous explanation.
But it did matter verrry much.
I learned it the hard way and therefore will never forget it.

Julian Day starts at noon - which keeps all the discoveries made during a nightly observing session within the same date.

Whereas the commonly known UT(C) begins at midnight and equals London time - without the political daylight saving in summer. The format can be written in decimal fractions of 24 hours where the date is then prepended followed by a dot.

So Rob took the spectrum at UTC 14:29 pm on January 14th 2018.
30 minutes after midnight on his local Australian January 15 AEST.
Or: UT 2018 January 14.6035 .

Got it. Thank you. :) Sorry for interrupting the thread with these trivia. Maybe somebody else reading here had the same question and confusion and my question has helped them, too.

[Rob_K]

Er, nearly Silv! With daylight saving we're UT+11. Therefore I took the shot at 14:29 + 11 hrs = 25:29 or about 1:30am local time on 15 Jan. :thumbsup:

Cheers -

[skysurfer]

You mean UTC Oh. 12 is the American way to determine both midnight and noon.
Unless the JD is New Zealand time zone based.
Btw, what a stupid invention those timezones, but that is a different topic.

[deniseselmo]

Fantastic! Congratulations!!

[Terry B]

No. Lifted from wikipedia.
The Julian Day Number (JDN) is the integer assigned to a whole solar day in the Julian day count starting from noon Universal time (https://en.wikipedia.org/wiki/Universal_time), with Julian day number 0 assigned to the day starting at noon on Monday, January 1, 4713 BC (https://en.wikipedia.org/wiki/4713_BC), proleptic Julian calendar (https://en.wikipedia.org/wiki/Proleptic_Julian_calendar) (November 24, 4714 BC, in the proleptic Gregorian calendar (https://en.wikipedia.org/wiki/Proleptic_Gregorian_calendar)),[1] (https://en.wikipedia.org/wiki/Julian_day#cite_note-1)[2] (https://en.wikipedia.org/wiki/Julian_day#cite_note-2)[3] (https://en.wikipedia.org/wiki/Julian_day#cite_note-3) a date at which three multi-year cycles started (which are: Indiction (https://en.wikipedia.org/wiki/Indiction), Solar (https://en.wikipedia.org/wiki/Solar_cycle_(calendar)), and Lunar (https://en.wikipedia.org/wiki/Metonic_cycle) cycles) and which preceded any dates in recorded history.[4] (https://en.wikipedia.org/wiki/Julian_day#cite_note-4) For example, the Julian day number for the day starting at 12:00 UT (https://en.wikipedia.org/wiki/Universal_Time) on January 1, 2000, was 2,451,545.