Dear Madam, Dear Sir,
I am a French amateur astronomer.
I am writing to report a probable misclassification concerning the object designated as SN 1962C.
Based on an investigation using both current and archival data, it appears that the object identified as a supernova in the galaxy MCG+03-41-085 is probably, in fact, a star located within our own galaxy.
The following points support this conclusion:
- The object remains visible in images I captured recently, on May 30, 2025 ; (which is unusual for a supernova originally observed in 1962);
- Additionally, data from the Gaia DR2 catalog indicate significant proper motion:
pmRA = +7.793 mas/yr
pmDEC = –6.905 mas/yr
These values are incompatible with an extragalactic object and suggest that it is a local star.
A discussion thread compiling these observations and analyses is available via the following links:
- Observation pages :
https://astro.julienquirin.fr/30_05_2025_abell_2151_amas_galactique_her…
https://astro.julienquirin.fr/SN1962C.jpg
(image dated May 30, 2025 ; 121 x 60 seconds at 2500 ISO ; T200/1000 mm Newton ; Canon Eos Ra camera)
- Forum discussion :
https://forum.julienquirin.fr/viewtopic.php?t=4815
Yours Sincerely,
Julien (Sébastien) QUIRIN
FRANCE
| Catalog | Name | Reported RA | Reported DEC | Reported Obj-Type | Reported Redshift | Host Name | Host Redshift | Remarks | TNS RA | TNS DEC | TNS Obj-Type | TNS Redshift |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TNS | 1962C | 16:05:04.980 | +17:34:54.41 | NA/Unknown | Anon. | 16:05:04.980 | +17:34:54.41 | NA/Unknown |
Comments
The Palomar Survey plate PS6239 showing SN 1962C presumably still exists .See
https://iopscience.iop.org/article/10.1086/133303/pdf
Does this confirm the field star and the apparent supernova are the same object ?
Dear Sir,
I would like to express my sincere thanks for the documents you kindly shared with me on this forum and via private message.
In his report, Mr. Fritz Zwicky noted that supernova SN 1962C was located slightly south and east of the galactic center (specifically, 5″ east and 1″ south of the center).
In his study, Mr. Alain Porter precisely determined the coordinates of SN 1962C as 16:02:49.79 +17:43:00.4.
These coordinates are consistent with the position of SN 1962C as displayed, for instance, using the ALADIN sky atlas software.
The luminous point visible in the image I captured on May 30, 2025, with my amateur telescope is therefore very likely SN 1962C.
This same point also appears in various professional astronomical databases, including those accessible via ALADIN.
This raises an intriguing question: why is SN 1962C still visible through an amateur telescope nearly 63 years after its initial discovery?
Furthermore, this object is listed in the GAIA DR2 catalog under the identifier 1199739607368172288. The proper motion data associated with this entry appear inconsistent with that of a distant supernova, especially considering that its host galaxy, MCG+03-41-085, is estimated to be approximately 600 million light-years away (if my calculations are correct).
I am deeply grateful for the opportunity to review the studies you provided. I would also like to extend my heartfelt thanks to Mr. Johan Richard of the Lyon Astrophysics Research Center, who kindly drew my attention to the proper motion of this object and took the time to respond to me, an amateur astronomer.
Warm regards,
Julien QUIRIN
France
P.S.: Below are some useful links related to SN 1962C:
SIMBAD database: https://simbad.u-strasbg.fr/simbad/sim-id?Ident=SN+1962C
GAIA DR2 data via VizieR: https://vizier.cds.unistra.fr/viz-bin/VizieR-S?Gaia%20DR2%2011997396073…
P.S. : astronomical coordinates determined by Mr Alan Porter (16:02:49.79 +17:43:00.4) are expressed in the B1950.0 reference frame
That there is an object at or close to the location given for SN 1962C is not in dispute. The object (a field star) appears in all surveys at approximately the same brightness including in a Palomar Supernova Survey (POSS-1) Plate dated 1950, predating the discovery of SN 1962C as part of the same survey. (available from the ESA Online Digitised Sky Survey website https://archive.eso.org/dss/dss )
If this field star is the object mis-identified by Zwicky as SN 1962C, it is surprising as the standard procedure for identifying transients is to compare (blink) with previous images. It is perhaps possible that the supernova identified by Zwicky is not this star but was very close to the same position. Only by examining the original discovery plate from the Palomar Supernova Survey (PS 6239) can you be sure that Zwicky was mistaken in the identification of SN 1962C
Dear Robin,
Thank you for your message.
I'm sharing this follow-up message to include the photographic plate from the POSS I database, taken before 1962, which features the galaxy MCG+03-41-085 (located just to the left of the reticle).
This image, which predates 1962 (just like the later ones), shows a bright spot at the exact location of the supernova described by Mr. Porter in his study (16:02:49.79 +17:43:00.4; B1950 reference frame).
The appearance of a point source at the precise coordinates reported by Mr. Porter on an image predating 1962 lends greater weight to the possibility of a misidentification than to its dismissal.
If SN 1962C had coordinates so close to this star, it is surprising that this was not mentioned either in Mr. ZWICKY’s report or in Mr. Porter’s study to clearly emphasize that there was no confusion with the star.
In his report, Mr. ZWICKY indicates that spectroscopic data were collected for some of the supernovae he lists, including SN 1962C.
Recovering this data, along with the original photographic plate, would be a way to confirm that SN 1962C was indeed a supernova.
Personally, I have searched for them in vain.
Perhaps, with the power of modern telescopes, professional astronomers may still be able to observe possible signs of an ancient supernova.
Until that is done, there remains a very strong probability that SN 1962C is actually a star in the Milky Way, as also suggested by the following data :
https://simbad.u-strasbg.fr/simbad/sim-id?Ident=SN+1962C
https://vizier.cds.unistra.fr/viz-bin/VizieR-S?Gaia%20DR2%2011997396073…
Kind regards
Julien QUIRIN