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A comparison of the spectrum this maximum with that by Miguel Rodriguez at a more typical maximum is in the latest BAA VSSC
https://britastro.org/vss/VSSC193.pdf
page 16It has now faded to visual magnitude ~7, a brightness more like that typically seen at maximum. The temperature from the TiO bands in the spectrum spectrum has dropped to that more typically seen at maximum, though the intensity of the Balmer emission remains high. Attached is a comparison between my most recent spectrum and that of Miguel Rodriguez taken at the 2020 maximum.
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This reply was modified 2 years, 7 months ago by
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This reply was modified 2 years, 7 months ago by . Reason: sp
Attachments:
Finally caught it tonight
40×20 sec clearAttachments:
The ZTF cutouts on the alerce site are useful. There is a faint something (the parent galaxy ?) at the coordinates in the template but this is clearly brighter with the SN (about the same brightness as two other stars in the same string on 25th)
(The clouds rolled in here as dusk fell)
Robin
Attachments:
Align and stack programs like Siril for example
https://siril.org/
can output a series of fits images as avi which can then be converted to animated gifs using various on line toolsCheers
RobinSince the point spread function of each of these stars would be expected to be similar, is it possible to use some kind of psf fitting technique to separate the flux from each component instead of aperture photometry ?
They are obviously having fun combing these images. Here they have found what is left of SN 2013ej in M74
https://www.wis-tns.org/astronotes/astronote/2022-147
which reached mag 12 back in August 2013 seen here in Damian Peach’s image.
http://www.damianpeach.com/deepsky/m74sne_2013_08_05dp.jpgNow past maximum. My two low resolution spectra bracketing the maximum here
https://britastro.org/observations/observation.php?id=20220718_154759_9e171ab7b4e26e1f
Cheers
RobinI see it has already started doing the more mundane stuff. A possible supernova on the Transient Name Server, reported today though from an observation made 2022-06-22
https://www.wis-tns.org/object/2022owj
(I wonder if they embargoed it until after the “first light” images had been published ?)Hi Stan,
There are quite a few images already this year in the members’ gallery
https://britastro.org/observations/?obj1Type=0&obj1txt=Noctilucent+cloud&obj1id=NLC
There is also dedicated section on the forum covering discussions on atmospheric phenomena, though it is pretty quiet
https://britastro.org/forums/forum/atmospheric-phenomena
Cheers
RobinNot sure if I’ve logged this one already but the old link to my profile
https://britastro.org/profile?id=146
which I may have put out there on the internet in the past
now points to
https://britastro.org/forums/reply/profile?id=146
which brings up a random unrelated posting on the forumThere is an early spectrum from the 2SPOT team from their robotic ALPY 600 setup in Chile
https://groups.io/g/spectro-l/message/412
which seems to be evolving fast compared with the description of one taken less than 12 hours later referenced in Atel 15420
https://www.astronomerstelegram.org/?read=15420In times of crisis, I find myself turning to Prof Ned Wright’s tutorials. These FAQ are useful here
What is the redshift ? https://www.astro.ucla.edu/~wright/cosmology_faq.html#z
Can objects move away from us faster than the speed of light? https://www.astro.ucla.edu/~wright/cosmology_faq.html#FTL
Are galaxies really moving away from us or is space just expanding? https://www.astro.ucla.edu/~wright/cosmology_faq.html#MXActually the formal definition of redshift z (eg as quoted for a particular object in the literature) does not involve velocity at all. It is determined by direct measurement z = (measured wavelength/rest wavelength)-1. It is when this is interpreted as a velocity without considering relativity, the frame of reference and the particular cosmological model that the problems occur
I don’t know know of any formal campaigns involving amateurs though the AAVSO did contact the author offering support and there are a number of observers contributing brightness measurements. Here is the thread on the AAVSO forum
https://www.aavso.org/sdssj14302303nsv6690-smbh-binary-collision-candidate
I took a couple more spectra and contacted the author who though they might be showing some changes and would follow it up with some measurements of their own, though I have not heard anything since. A quick look at the AAVSO light curve does not show anything obvious.Cheers
RobinMy guess is that Robin’s post is the last one on the page and the javascript has a fence-post error which led it to create a new page.
Also if I click on the post number next to my post
https://britastro.org/forums/topic/new-website-feedback/page/5#post-609928
it takes me to the top of the next page instead of to the post. It should point to
https://britastro.org/forums/topic/new-website-feedback/page/4#post-609928Robin
Have the attachments been stripped from pre uplift posts ? eg
https://britastro.org/forums/topic/using-miles-stars-to-check-spectrum-quality#post-577636
Is there any news on this? Are the stripped attachments recoverable or have they been lost ?
Thanks
RobinBased on the notes in the WDS it is considered an optical pair which I take to mean it is not a binary but just two stars “passing in the night”
http://vizier.u-strasbg.fr/viz-bin/VizieR?-6N&-out.form=H0&://*&-source%3DB/wds/notes&WDS%3D%3D%3D05597%2b3713Cheers
RobinEDIT: it appears the link has broken somewhere. I’ll leave you to navigate to it via WDS
According to the Washington Double Star Catalogue
http://vizier.u-strasbg.fr/viz-bin/VizieR-3?-source=B/wds/wds
the separation was 2.1 arcsec in 1871 and 4.2 in 2019. This reference has it as 3.9 arcsec in 2002
https://arxiv.org/abs/1012.3383
so also consistent with it widening currently.
Visual doubles is not my field but I guess 4 arcsec separation with a 5 magnitude difference in brightness could be pretty toughCheers
RobinAre the scanned versions of the JBAA supplied to ADS by the BAA or do they generate them? I noticed that vol.128, no.3, p.187 seems to be missing there. Instead there are two copies of p 185 and some wrong numbering in this series
https://articles.adsabs.harvard.edu/full/seri/JBAA./0128//0000187.000.htmlCheers
Robin -
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