DRAFT
2023-05-22 15:27:24
Type: Object/s-Data/Analysis
Bibcode: 2023TNSAN.133....1Y
Amateur astronomer contribution to constraining the explosion time and rise of the Type II SN 2023ixf in M101
Authors: Ofer Yaron, Rachel Bruch, Ping Chen, Ido Irani, Erez Zimmerman, Avishay Gal-Yam (WIS), Yu-Jing Qin (Caltech)
Keywords: Supernova
Abstract:
Following the discovery by Koichi Itagaki of SN 2023ixf in the nearby galaxy M101, images obtained by amateur astronomers from around the globe, as well as reports based on such data, have been streaming in to the TNS. These data are very valuable and contribute additional early photometry points and constraining non-detections of the event. Here, we display some of the accumulated data, and strongly encourage the contribution of additional images in order to further constrain as accurately as possible the explosion time and the behavior of the rise of this exciting event. We plan to undertake additional calibration efforts in order to further increase the utility of accumulated amateur data.

SN 2023ixf was discovered by Koichi Itagaki on 2023-05-19 17:27 UT (2023TNSTR1158....1I). Twelve hours later ZTF reported their first detection of May 19th 07:45 UT -  about 10 hours before Itagaki's discovery time. Stephen Limeburner reported on his earliest images from  May 19th 03:41 UT - 4 hours before the ZTF discovery image (AT Report 178124 & AstroNote 2023-128), followed by additional detections and non-detection from Norman Hamann (AstroNote 2023-127). A deep non-detection around May 18th 10 UT was obtained by Kennedy, and detections by Oostermeyer beginning around May 18th 21:30 UT (AstroNote 2023-125).

An AstroNote summarizing observations from East Asian longitudes pinpoints the estimated explosion time (up to the depth and accuracy of the last non-detection) to within one hour - May 18th ~19:30-20:30 UT (AstroNote 2023-130).

Additional astronomers continue to send in their data, and in the attached figure we plot some of the photometry points that have been accumulated and mentioned in the AstroNotes so far. However, we caution that the values of both the detections and non-detection limits are preliminary and may not be fully calibrated yet. Also, some of the limits are shallow, hence we encourage report and analysis of images obtained also before what is specified as the "current latest non-detection" as well as throughout the rise.

It is quite likely that for this specific event, on the spiral arm of such a nearby and extensively photographed galaxy, images obtained by amateur astronomers and astrophotographers from all possible timezones could cover the entirety of the rise time in a well sampled manner. Thus, enabling us to both pin down a very accurate estimation of the explosion time (through direct imaging, rather than light-curve extrapolation), and to obtain a good characterization of the rise behaviour.

We highly encourage all astronomers to continue reporting their valuable findings for this event! In particular, any early color information (wide/narrow-band imaging in any filter).

Show current TNS values
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 2023ixf 14:03:38.564 +54:18:42.02 SN II 0.000804 M101 14:03:38.562 +54:18:41.94 SN II 0.0008
AstroNote Publication Timestamp Title Authors
2023-125 2023-05-21 06:27:50 Pre-Discovery Images of SN 2023ixf taken at T-[9,18,33] hours Keming Zhang (UC Berkeley), David Kennedy, Bronco Oostermeyer, Joshua Bloom (UC Berkeley), Daniel A. Perley (LJMU)
2023-127 2023-05-21 12:48:45 Pre-Discovery Images of SN 2023ixf on 18th May 2023 21:19:13 UTC Norman Hamann
2023-128 2023-05-21 14:30:25 Limeburner Prediscovery images of SN 2023ixf Stephen Limeburner
2023-130 2023-05-22 06:15:38 Onset of SN 2023ixf observed over East Asian longitudes Yiming Mao, Mi Zhang, Guangyao Cai, Jinan Chen, Jin Chen, Xing Gao, Keying Li, Xiaodong Lyu, Yujing Qin, Guoyou Sun, Shijun Xu, Zangyun Zhang, Jiashuo Zhang, Jingyuan Zhao, Xin Zheng, Wenjie Zhou, Quanzhi Ye
2023-123 2023-05-20 14:49:49 Filippenko Prediscovery Image of SN 2023ixf A V. Filippenko, W. Zheng, and Y. Yang (U.C. Berkeley)
2023-124 2023-05-20 19:27:01 ATLAS forced photometry pre-discovery limit of SN 2023ixf M. D. Fulton, M. Nicholl, K. W. Smith, S. Srivastav, D. R. Young, M. McCollum, T. Moore, S. Sim, J. Weston, X. Sheng (QUB), L. Shingles (GSI/QUB), J. Sommer (LMU/QUB), A. Aamer (UoB/QUB), S. J. Smartt, H. Stevance, L. Rhodes, A. Andersson (Oxford), L. Denneau, J. Tonry, H. Weiland, A. Lawrence, R. Siverd (IfA, University of Hawaii), N. Erasmus, W. Koorts (South African Astronomical Observatory), J. Anderson (ESO), A. Jordan, V. Suc (UAI, Obstech) A. Rest (STScI), T.-W. Chen (TUM), C. Stubbs (Harvard)
2023-120 2023-05-20 01:17:30 ZTF Pre-Discovery Forced Photometry of SN 2023ixf Daniel A. Perley (LJMU), Ido Irani (Weizmann)
File Comments
amateur_photometry_SN2023ixf_1.pdf A plot showing some of the derived photometry points so far and up to Itagaki's official discovery time, mainly from the images and reports provided by amateur astronomers. N.D. stands for Non-Detection. The points from Stephen Limeburner and Norman Hamann were calibrated to the R band. The XOSS points were calibrated to Bessel V, as mentioned in AstroNote 2023-130. All times are UT. We assume a distance of 6.71 Mpc to M101 (Riess et al. 2016).

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