Nova V462 Lup - June 2025

[Pierre_C]

Sky & Telescope is reporting on a newly-discovered nova in Lupus which may approach naked-eye visibility.
https://skyandtelescope.org/astronomy-news/bright-nova-lights-up-lupus/

It is currently recorded at magnitude 6.4 by the American Association of Variable Star Observers.
https://apps.aavso.org/webobs/results/?star=000-BQF-448&num_results=200

The coordinates are given in the Central Bureau for Astronomical Telegrams as R.A. = 15h08m03s.27, Decl. = -40d08'29".6.
http://www.cbat.eps.harvard.edu/iau/cbet/005500/CBET005570.txt

[AstralTraveller]

It's not far from beta Lup and easy to find. Last night I estimated it at mag 6.1 but other observers had 5.9 and 5.8. It was measured at B= 6.367, V= 6.030, I= 5.637. It's position is RA 15:08:03.274 Dec -40:08:29.58. Pre-discovery it was below mag 23.

Finder charts available here https://apps.aavso.org/vsp/chart/?chartid=X40347B or plot your own by customising the options here https://apps.aavso.org/vsp/?star=V462+Lup&fov=60&maglimit=14.5&resolution=150&north=up&east=left

If anyone can image it - without saturating the stars - it might be valuable. [People with colour sensors should probably defocus a bit to spread the light evenly over a fair number of pixels.] Spectroscopy would be great.

[Saturnine]

Took the opportunity to observe the Nova V462 Lupi tonight using a 102mm f7 ED and a 24mm WA eyepiece, thanks to some clear calm skies for a change. Estimated the visual magnitude at 5.6 / 5.7 , comparing it to the adjacent field stars, so it may still be brightening. Using the AAVSO finder chart and Stellarium made it quite easy to find and estimate the magnitude. Will be interesting to see how my guess compares to more experienced nova observers.

[RichardJ]

Observed the nova last night with 10 x 50 binoculars. Easy to spot.
Estimated the magnitude to be 5.8.
Posted an image in the astrophotography forum.

RichardJ 🙂

[Crater101]

Managed to spot it last night on a rare clear and bitingly cold evening with a WO Fluorostar 91. I've never been the best at estimating magnitudes, but I would have estimated about 5.8, however that may have been a combination of local seeing and Bortle 6 skies.

[Pierre_C]

Thanks for sharing the link to the finder comparison charts, David – very helpful.

Tonight, I estimated it to be at visual magnitude 5.6 at 19:02pm AEST (09:02 UTC), Thursday 19 June 2025. In comparison to the AAVSO reference stars, it looked brighter than 5.8 and dimmer than 5.4 – halfway between.

I used 10x50 Nikon Aculon A211 binoculars from suburban Melbourne, Bortle 5.

[AstralTraveller]

Jeff, that estimate is very good and aligns with other estimates, including mine. You obviously have a talent for this :). Magnitude estimates can be found here https://apps.aavso.org/v2/data/search/photometry/?target=V462+Lup&start_date=&end_date=&observer=&obs_campaign=&submit=Search
It now appears to be in the 5.5-5.7 range.

The comparison sequence has been extended up to 4.5 so you could update your charts. They recommend plotting at AB scale (7.5 degrees) but if you go out to A scale (15 degrees) you get a handy 5.7 comparison star. You can get these by asking for charts X40364JR or X40364ADB respectively here https://apps.aavso.org/vsp/. These are plotted to mag 10 which is probably a bit faint but will be useful if you continue following the nova as it fades. [The real reason is that I habitually plot to mag 10 for my 80mm frac and mag 12 for the 150mm frac as this is just slightly below the limiting mag of these scopes in my backyard.]

There is also news about the progenitor star here https://forums.aavso.org/t/mag-8-7-transient-in-lupus-rising-nova/2669/35

[Pierre_C]

I had a similar result tonight under the same observing conditions - magnitude 5.6, brighter than 5.8 and dimmer than 5.4 – roughly halfway between. 18:44hrs AEST (08:44 UTC) Friday 20 June 2025, Melbourne.

[bojan]

Here is mine..

Spectrum will hopefully follow tomorrow night.

[Saturnine]

Have just been observing V462 Lupi again and my estimates are very similar to Pierre_Cs' number. Compared to nearby HUB12, mag 5.8 and HDO242, mag 5.2, the nova magnitude was roughly in between, so about mag 5.6! Used the same equipment as the other night and the seeing tonight is quite good, for a change. Bojans' and Captain Cooks' images seem to agree with the estimates.

[bojan]

Interesting detail for me is the colour.. whitish. I expected more red...

[Rob_K]

The spectrum is quite flat, as of last night at least, but as the nova starts to fade the emissions should show through again, with the H-alpha emission dominating. I've attached my low-res spectrum from 19 June showing the flat spectrum, with a narrow absorption at H-beta and possibly absorption & very small emission at H-alpha (p-Cygni profile). Hi-res spectra at the ARAS group confirm this. Will be interesting to see if the emissions show tonight!

Cheers -

Rob

[RichardJ]

Imaged it from a remote observing site (this morning our time) and did aperture photometry. I estimate the current magnitude to be 5.34.

RichardJ :)

[bojan]

Spectrum, obtained with C11 + SA100+prism + Canon 60Da.
Very crude cal but yes, H-alpha and H-beta are clearly visible.

[Pierre_C]

Similar again for me tonight - visual magnitude 5.6, 19:03hrs AEST (09:03 UTC) Saturday 21 June 2025, Melbourne.

I am finding the AAVSO Manual helpful for refining technique and uploading results to the AAVSO - https://www.aavso.org/visual-star-observing-manual

What do the spectra tell us about the nature and evolution of this nova? (I have not tried spectroscopy).

[Rob_K]

Excellent Bojan! :thumbsup: My spectrum tonight also shows the emissions.

Cheers -

[Pierre_C]

It seems slightly dimmer to me tonight at visual magnitude 5.7, 18:43hrs AEST (08:43 UTC) Sunday 22 June 2025, Melbourne. It seems closer in brightlness to the mag 5.8 reference star nearby than the mag 5.4 reference star on the other side of delta Lupi. There is some thin cloud where I am observing.

[Saturnine]

Had another look at V462 and I would agree with your estimate tonight, it looked just marginally brighter than HUB12 , which is also listed as variable, between mag. 5.75 / 5.81, so still about 5.6 / 5.7 mag. Observed under clear steady Bortal 5 skies.

[AstralTraveller]

Pierre, and anyone else who is enjoying estimating the nova's brightness, atm S Carina is about the same brightness. R Hya and RR Sco are brighter than mag 7 and T Cen, R Nor & RV Sgr are a bit fainter. And there are plenty more in the range of my 15cm achro from suburban Wollongong, actually quite a few can be seen in the 80mm.

[bojan]

Spectrum tonight (trough wind and clouds), no significant change from last night.

[Pierre_C]

It seems slightly dimmer to me again tonight at visual magnitude 5.8, 19:11hrs AEST (09:11 UTC) Monday 23 June 2025, Melbourne. It seems very close in brightlness to the mag 5.8 HUB12 reference star nearby. There is some thin cloud where I am observing.

I am finding this nova a good one to train on, as it seems to be changing slightly every day.

Thanks for the suggestions, David. R Hya seems intriguing.

[EpickCrom]

I finally had a chance to observe Nova Lupi last night immediately after getting home from work to take advantage of some clear(and cold!) skies.

Rugged up on my recliner and using my 10x50mm binoculars I easily found the nova, which I estimate to be around 5.7 magnitude. It appeared just about identical in brightness as nearby HR Lupi which is a very slight variable star.

Clear Skies
Joe

[Orion31]

Here is my photo from my little Seestar S30. I had to enter coordinates directly and should’ve re centered. If I get a chance to image again before it dims into obscurity I will center it better. Still, I was happy with the results.

[Pierre_C]

Thanks for sharing your insights, observations, spectra and photos, everyone. It really enriches the experience.

The AAVSO light curve of observations can be found at: https://www.aavso.org/LCGv2/

Enter 'V0462 Lup' as the 'Star name' and press 'Send'. The Julian dates can be changed to calendar dates using the 'Preferences' tab.