Abstract
Here I describe 184 mid-infrared detections of supernovae (SNe) in co-added images of the NEOWISE mission. 15 of the SNe had previously unknown long-lasting mid-IR detections with durations of more than a year. I find 7 SNe which have previously unknown SN 2010jl-like mid-infrared evolution. There are also long detections around one type IIb (SN 2016gkg), type IIP (SN 2016X) and type IIL (SN 2016iot). An unusual supernova is SN 2018hna, which shows a drastic color-change in mid-infrared. SN 2018hna begins as a transient with no IR-excess 31 days after the discovery, but changes 158 days later into a transient with strong IR-excess.
1. Introduction
Supernovae (SNe) are known sometimes to produce mid-infrared transients. The dust causing this brightening is either produced in the supernova or it is an interaction with pre-existing dust in the circumstellar medium (Szalai et al. 2019). Past detections of SNe in mid-infrared are primarily either from NEOWISE (Moriya et al. 2020) or from the Spitzer Space Telescope (Szalai et al. 2019). Here I searched all the SNe II from the Transient Name Server (TNS) between 2014 January 1 and 2019 December 31. From these 1200 SNe I find 184 detections using the wiseview-tool (Caselden et al. 2018). This tool allows for a customized coadding of WISE and NEOWISE images and it displays them in a time-resolved animation. I used a 0.5 yr coadd mode for the best result in detecting the mid-IR transients. Most detections last for a few images and only 18 objects show long lasting mid-infrared detections.
Here I am going to discuss some of the SNe from the Table 1, using light curves produced with the IRSA NEOWISE-R (Mainzer et al. 2014) single exposure table, using primarily w1mpro. The epochs that I describe are separated by about 0.5 yr. Previously undescribed long detections (more than 3 epochs) are in the following SNe: SN 2016X (ASASSN-16at), SN 2016eei (Gaia16ate), SN 2016cyi (PTSS-16jik), SN 2016gkg, SN 2016idl (Gaia16bug), SN 2016ieq (Gaia16buy), SN 2016iot (Gaia16byk), SN 2017ahn (DLT17h) SN 2017gas (ASASSN-17kr), SN 2017gkp (Gaia17ced), SN 2017gvb (ATLAS17ldj), SN 2017hcc (ATLAS17lsn), SN 2017ijn (ATLAS17nhp), SN 2018gn (ASASSN-18ap), SN 2018cez (ASASSN-18ls). The supernova SN 2018hna with the unusual color-change is also described in the next section.
Table 1. List Mid-IR Detections in Supernovae
Name | R.A. | Decl. | Mid-IR Transient | Object Type | Reference Mid-IR Detections | Host Name |
---|---|---|---|---|---|---|
(deg) | (deg) | |||||
(1) | (2) | (3) | (4) | (5) | (6) | (7) |
SN 2014B | 196.07375 | −10.333669 | detection | SN IIP | this work | NGC 4939 |
SN 2014F | 277.632458 | 67.9915806 | detection | SN II | this work | NGC 6667 |
SN 2014G | 163.642208 | 54.2991389 | detection | SN IIn | Szalai et al. (2019) | NGC 3448 |
SN 2014af | 131.838171 | 73.2204694 | detection | SN IIP | this work | Anon. |
SN 2014ab | 207.024958 | 7.38788889 | long detection | SN IIn | Moriya et al. (2020) | UGC 08728 NOTES01 |
SN 2014az | 353.095171 | 15.8529389 | detection | SN IIP | this work | NGC 7691 |
SN 2014bi | 181.512458 | 47.4926389 | detection | SN IIP | Szalai et al. (2019) | NGC 4096 |
SN 2014cl | 34.0379208 | −11.934061 | detection | SN IIb | this work | IC 217 |
SN 2014cq | 140.873129 | −63.674530 | detection | SN IIb | this work | ESO 091- G 011 |
SN 2014cw | 333.860621 | −10.476280 | detection | SN II | this work | Anon. |
SN 2014cx | 14.9492917 | −7.5718305 | detection | SN II | Szalai et al. (2019) | NGC 337 |
SN 2014dq | 335.817042 | −28.9755 | detection | SN II | this work | ESO 467-G51 |
SN 2015C | 199.626958 | −14.612388 | unclear | SN IIP | this work | IC 4221 |
SN 2015 da | 208.100458 | 39.6912778 | long detection | SN IIn | Tartaglia et al. (2020) | NGC 5337 |
SN 2015W | 104.429292 | 13.5793611 | detection | SN IIP | this work | UGC 3617 |
SN 2015bh | 137.396079 | 33.1228111 | unclear | SN IIn | this work | NGC 2770 |
SN 2015J | 113.771579 | −69.131419 | detection | SN IIn | this work | Anon. |
SN 2015P | 192.628 | −10.877919 | detection | SN IIP | this work | MCG -02-33-20 |
SN 2015an | 126.062917 | −18.774583 | detection | SN IIP | this work | IC 2367 |
SN 2015aq | 141.435542 | 34.2766889 | detection | SN IIP | this work | UGC 5015 |
SN 2015ay | 17.4448708 | 13.3080306 | detection | SN II | this work | UGC 722 |
SN 2015as | 152.047371 | 51.8446889 | detection | SN II | this work | UGC 5460 |
SN 2015ba | 218.121621 | 49.8929194 | detection | SN II | this work | IC 1029 |
SN 2015bi | 218.06375 | 26.3254444 | unclear | SN IIb | this work | VV 839 |
SN 2016B | 178.767692 | 1.71855 | detection | SN IIP | this work | CGCG 012-116 |
SN 2016C | 204.522083 | −17.85425 | detection | SN IIP | Jencson et al. (2019) | NGC 5247 |
SN 2016L | 225.114458 | −13.5525 | detection | SN IIP | this work | UGCA 397 |
SN 2016aa | 121.06675 | 61.5618611 | detection | SN IIP | this work | PGC 22658 |
SN 2016X | 193.815042 | 0.09981944 | long detection | SN IIP | this work | UGC 08041 |
SN 2016aai | 192.6168 | −10.841394 | detection | SN IIP | this work | 0 |
SN 2016bdu | 197.558129 | 32.520575 | detection | SN IIn | this work | |
SN 2016bla | 116.36225 | 29.8909806 | detection | SN IIP | this work | SDSS J074526.98+295326.4 |
SN 2016ase | 175.644583 | −25.912583 | unclear | SN II | this work | ESO 504- G 009 |
SN 2016bev | 116.959208 | −18.736888 | detection | SN II | this work | |
SN 2016bkv | 154.580458 | 41.4275833 | detection | SN II | this work | NGC3184 |
SN 2016bpq | 283.372063 | 30.6792 | detection | SN II | this work | |
SN 2016blx | 88.2483333 | −17.86225 | detection | SN II | this work | IC438 |
SN 2016blz | 235.122083 | 0.91030556 | detection | SN II | this work | SDSS J154029.29+005437.4 |
SN 2016bme | 134.162867 | 52.10225 | detection | SN II | this work | UGC4671 |
SN 2016bmi | 278.634125 | −58.529111 | detection | SN IIP | this work | IC4721 |
SN 2016ccf | 131.046042 | 34.7155 | detection | SN IIP | this work | NGC2649 |
SN 2016ccm | 212.495417 | 17.7633611 | detection | SN IIP | this work | IC983 |
SN 2016cok | 170.079304 | 12.9824 | unclear | SN IIP | this work | M66 |
SN 2016cvk | 334.955792 | −40.667555 | detection | SN IIn-p | this work | ESO-344-G21 |
SN 2016eei | 46.0820833 | −57.583861 | long detection | SN IIn | this work | |
SN 2016cyi | 334.243292 | 46.7353556 | long detection | SN IIn | this work | ZOAG G097.31-08.31 |
SN 2016cyx | 35.3449417 | 16.5652639 | detection | SN II | this work | UGC 01814 |
SN 2016emw | 85.225 | −12.243277 | unclear | SN II | this work | |
SN 2016enk | 231.62275 | 41.7344611 | detection | SN II | this work | UGC 09857 |
SN 2016eso | 74.8752333 | −28.8609 | detection | SN IIn | this work | ESO 422- G 019 |
SN 2016ezh | 29.5197458 | −0.8727055 | long detection | SN II | Jiang et al. (2017) | |
SN 2016gfy | 111.691375 | 85.7642111 | detection | SN II | this work | NGC2276 |
SN 2016gkg | 23.5601667 | −29.440061 | long detection | SN IIb | this work | NGC 613 |
SN 2016hbd | 44.0258167 | 27.7015417 | blue detection | SN IIP | this work | |
SN 2016hgm | 20.5492208 | 0.95205556 | detection | SN II | this work | NGC 493 |
SN 2016iaf | 86.7701292 | −25.770508 | detection | SN IIn | this work | |
SN 2016hvu | 338.9815 | 20.3201611 | unclear | SN IIP | this work | NGC 7316 |
SN 2016hwn | 181.070333 | 21.8005111 | detection | SN II | this work | KUG 1201+220 |
SN 2016idl | 151.621292 | 22.4456306 | long detection | SN IIn | this work | |
SN 2016ieq | 320.604958 | −11.948561 | long detection | SN IIn | this work | |
SN 2016ija | 63.0316667 | −32.852911 | detection | SN II | this work | NGC1532 |
SN 2016iot | 249.713333 | 39.8143694 | long detection | SN IIL | this work | |
SN 2017it | 92.65475 | −34.141038 | detection | SN II | this work | |
SN 2017pn | 71.60245 | −11.988402 | detection | SN II | this work | |
SN 2017ati | 147.48625 | 67.1832111 | detection | SN IIb | this work | |
SN 2017ahn | 159.322792 | −41.618130 | detection | SN II | this work | NGC3318 |
SN 2017bzb | 344.322167 | −41.015961 | bright detection | SN II | this work | NGC7424 |
SN 2017cfa | 149.266221 | −7.8808722 | unclear | SN IIP | this work | |
SN 2017cff | 204.820833 | 35.1441194 | unclear | SN IIP | this work | GALEXASC J133917.08+350841.1 |
SN 2017eaw | 308.684333 | 60.1932889 | bright detection | SN II | 2018MNRAS.481.2536K | NGC 6946 |
SN 2017faa | 199.76625 | −2.51275 | detection | SN II | this work | |
SN 2017faf | 263.666621 | 26.3061028 | detection | SN II | this work | |
SN 2017fck | 79.9765417 | −56.185688 | detection | SN IIn | this work | |
SN 2017fqk | 43.5092208 | 2.96793889 | detection | SN II | this work | NGC 1137 |
SN 2017fvr | 71.867625 | 23.9827306 | detection | SN IIP | this work | |
SN 2017gas | 304.297333 | 58.20225 | long detection | SN IIn | this work | 2MASX J20171114+5812094 |
SN 2017gkp | 131.799125 | −33.753030 | long detection | SN II | this work | |
SN 2017ghw | 359.394808 | 2.08643889 | unclear | SN IIn | this work | |
SN 2017gkk | 138.435708 | 76.4790389 | detection | SN IIb | this work | NGC2748 |
SN 2017gmr | 38.87575 | −9.3541888 | detection | SN II | this work | NGC0988 |
SN 2017gra | 49.3820417 | −35.152080 | detection | SN IIn | this work | |
SN 2017gvb | 121.176583 | 61.5273694 | long detection | SN IIn | this work | |
SN 2017hbg | 111.905625 | 35.6084889 | detection | SN II | this work | MCG+06-17-007 |
SN 2017hca | 132.421125 | −8.0920111 | detection | SN II | this work | |
SN 2017hcd | 25.7160417 | 31.4823806 | detection | SN IIn | this work | |
SN 2017hcc | 0.96079167 | −11.474611 | long detection | SN IIn | this work | |
SN 2017hbj | 67.782 | −63.31975 | detection | SN II | this work | ESO-084-G-020 |
SN 2017hpi | 123.930792 | −28.855461 | detection | SN II | this work | AM 0813-284 |
SN 2017hpn | 137.007333 | 27.2514722 | detection | SN IIP | this work | PGC25678 |
SN 2017ijn | 145.378833 | −11.1995 | long detection | SN IIn | this work | |
SN 2017iit | 75.8339583 | 18.4508 | detection | SN II | this work | |
SN 2017ivh | 204.901042 | −11.482219 | detection | SN II | this work | |
SN 2017ivv | 307.207417 | −4.3826083 | detection | SN II | this work | |
SN 2017jbj | 12.0225833 | −2.7895555 | detection | SN II | this work | NGC 259 |
SN 2018bl | 126.048292 | −77.787930 | detection | SN II | this work | |
SN 2018gk | 248.97525 | 40.0327806 | detection | SN II | this work | WISE J163554.27+400151.8 |
SN 2018gn | 26.676875 | 32.5081389 | long detection | SN II | this work | KUG 0143+322 |
SN 2018gj | 248.009583 | 78.2113694 | detection | SN II | this work | NGC 6217 |
SN 2018mc | 270.253558 | 61.6963556 | detection | SN IIb | this work | |
SN 2018pn | 119.047083 | 45.5267778 | detection | SN IIP | this work | SDSS J075611.44+453138.3 |
SN 2018pq | 193.880379 | −50.054711 | detection | SN II | this work | IC 3896A |
SN 2018yt | 134.898292 | 45.6116389 | unclear | SN II | this work | |
SN 2018rz | 216.797667 | −2.2697805 | unclear | SN IIP | this work | NGC5618 |
SN 2018yo | 190.2965 | −1.5888305 | detection | SN IIP | this work | UGC 7840 |
SN 2018zd | 94.5132917 | 78.3669889 | detection | SN II | this work | NGC 2146 |
SN 2018aad | 59.5064167 | −65.506761 | detection | SN II-pe | this work | GALEXASC J035801.64-653024.6 |
SN 2018afm | 119.854217 | 16.4262722 | detection | SN II | this work | UGC 4139 |
SN 2018ahe | 224.289617 | 19.6998944 | unclear | SN IIP | this work | UGC 9620 |
SN 2018amc | 164.503208 | 72.4407194 | detection | SN II | this work | GALEXASC J105800.28+722628.0 |
SN 2018ant | 129.131042 | −11.828019 | detection | SN II | this work | |
SN 2018anu | 264.059796 | 18.9823861 | detection | SN II | this work | |
SN 2018aoq | 182.65925 | 39.3966306 | detection | SN II | this work | NGC 4151 |
SN 2018lua | 256.477417 | 33.5208611 | detection | SN IIn | this work | |
SN 2018awp | 4.05870833 | −31.617461 | detection | SN IIn | this work | |
SN 2018ctj | 217.812367 | 17.1929972 | detection | SN IIn | this work | |
SN 2018bbv | 238.953458 | −68.870730 | detection | SN II | this work | ESO-068-G-013 |
SN 2018bsz | 242.412967 | −32.062675 | detection | SN II | Chen (2019) | 2MASX J16093905-3203443 |
SN 2018bwd | 222.71025 | −77.882269 | unclear | SN II | this work | |
SN 2018cgq | 13.5105833 | 47.1807111 | detection | SN IIP | this work | |
SN 2018cez | 21.2328875 | −19.802930 | long detection | SN II | this work | GALEXASC J012455.64-194808.6 |
SN 2018cnv | 342.366629 | −24.383469 | detection | SN IIn | this work | |
SN 2018coq | 343.776167 | 11.2576111 | detection | SN II | this work | SDSS J225506.55+111531.8 |
SN 2018cuf | 319.048125 | −64.482638 | detection | SN II | this work | IC5092 |
SN 2018cvk | 298.883333 | −49.886538 | detection | SN IIn | this work | ESO 233- G 007 |
SN 2018dyv | 295.822042 | −54.570661 | detection | SN IIn | this work | 2MASX J19431917-5434257 |
SN 2018dzc | 275.788583 | 21.249 | unclear | SN II | this work | UGC 11216 |
SN 2018eog | 307.050208 | −3.1363305 | unclear | SN II | this work | 2MASS J20281135-0308096 |
SN 2018fmf | 144.62225 | 76.3199 | detection | SN IIP | this work | |
SN 2018fsc | 6.96083333 | 6.30603333 | detection | SN II | this work | |
SN 2018fru | 204.015667 | 66.3012111 | detection | SN II | this work | |
SN 2018get | 113.538108 | 4.54926944 | detection | SN II | this work | UGC 03912 |
SN 2018gkf | 118.2995 | 23.6517306 | detection | SN IIn | this work | |
SN 2018gjx | 34.0649167 | 28.5912806 | detection | SN IIb | this work | NGC 865 |
SN 2018hay | 140.823708 | 42.3801194 | detection | SN II | this work | SDSS J092317.60+422248.7 |
SN 2018hmx | 128.413917 | 55.5980806 | detection | SN II | this work | |
SN 2018hoa | 354.300458 | 40.7217889 | detection | SN II | this work | |
SN 2018hna | 186.550292 | 58.3141194 | blue then red bright de | SN II | this work | UGC7534 |
SN 2018hpb | 330.393792 | −17.46255 | unclear | SN IIn | this work | |
SN 2018hov | 135.50175 | 12.3564306 | detection | SN II | this work | SDSS J090159.96+122119.8 |
SN 2018hyw | 125.072283 | 20.8755972 | detection | SN II | this work | UGC 4344 |
SN 2018jah | 136.793667 | 43.9207806 | unclear | SN II | this work | |
SN 2018imf | 190.672458 | 13.2652306 | detection | SN IIP | this work | NGC 4639 |
SN 2018iuq | 106.472625 | 12.8929611 | detection | SN II | this work | |
SN 2018jkb | 35.2908333 | −4.0732694 | detection | SN II | this work | |
SN 2018khh | 330.816625 | −55.976788 | detection | SN IIn | this work | 2MASX J22031497-5558516 |
SN 2018lmy | 276.11575 | 46.6193111 | detection | SN IIn | this work | |
SN 2018ktv | 248.015667 | 39.6083194 | detection | SN IIL | this work | |
SN 2018lkg | 106.645375 | 63.8486944 | detection | SN IIn | this work | |
SN 2019qt | 224.794375 | 43.8199111 | detection | SN IIn | this work | |
SN 2019va | 203.811167 | 44.7662889 | detection | SN IIP | this work | |
SN 2019bjr | 130.748467 | 59.5678528 | detection | SN IIP | this work | |
SN 2019zc | 7.372475 | −13.478525 | detection | SN II | this work | |
SN 2019bhg | 254.859167 | 46.79915 | detection | SN IIP | this work | |
SN 2019alr | 355.029833 | 16.4845306 | detection | SN IIn | this work | |
SN 2019bao | 157.327167 | 6.12273056 | detection | SN IIb | this work | |
SN 2019bip | 158.137404 | −19.075380 | detection | SN II | this work | |
SN 2019cpo | 237.025408 | 66.9024861 | unclear | SN II | this work | |
SN 2019aafi | 337.992417 | 43.8394722 | detection | SN IIn | this work | |
SN 2019dke | 193.409167 | −26.292061 | detection | SN II | this work | ESO 507- G 042 |
SN 2019dnz | 297.131154 | 2.91375 | detection | SN IIn | this work | |
SN 2019dma | 343.707692 | 36.543625 | unclear | SN II | this work | |
SN 2019dtt | 338.656292 | 0.17571111 | detection | SN II | this work | |
SN 2019edo | 182.964942 | 24.1365833 | detection | SN II | this work | NGC 4162 |
SN 2019esa | 118.753958 | −76.411961 | detection | SN IIn | this work | ESO 035- G 018 |
SN 2019etp | 359.3465 | 30.9906306 | detection | SN II | this work | UGC 12864 |
SN 2019fcn | 121.783558 | −28.056361 | detection | SN II | this work | ESO 430- G 020 |
SN 2019fuo | 232.930783 | 16.7137056 | detection | SN II | this work | |
SN 2019hhh | 21.64525 | 51.7213306 | detection | SN IIP | this work | |
SN 2019hsw | 140.140654 | 64.0730444 | detection | SN II | this work | NGC 2805 |
SN 2019ibk | 26.546375 | −16.284580 | detection | SN II | this work | |
SN 2019jys | 3.856875 | −14.253819 | detection | SN IIn | this work | |
SN 2019jyw | 16.625925 | −2.1987861 | detection | SN II | this work | |
SN 2019knu | 49.4695917 | −7.3031888 | detection | SN II | this work | 2MASS J03175281-0718048 |
SN 2019lkx | 55.2621667 | 34.6520889 | detection | SN II | this work | |
SN 2019lkw | 256.287917 | 33.44255 | detection | SN II | this work | |
SN 2019aafj | 222.165833 | 30.678 | unclear | SN IIn | this work | |
SN 2019mom | 28.9022 | 53.5918944 | detection | SN IIn | this work | |
SN 2019mhm | 287.849917 | −57.055161 | detection | SN IIP | this work | NGC6753 |
SN 2019oje | 299.618508 | −37.538763 | detection | SN IIb | this work | |
SN 2019osl | 69.7263333 | 18.8361806 | unclear | SN II | this work | |
SN 2019smj | 117.419667 | 5.07421111 | detection | SN IIn | this work | WISEA J074940.69+050411.1 |
SN 2019tua | 329.501167 | 24.2658611 | detection | SN II | this work | |
SN 2019vve | 118.939546 | 32.4060333 | unclear | SN II | this work | |
SN 2019vxm | 299.618917 | 62.1377306 | detection | SN II | this work |
Note. The "mid-IR transient" column gives some information about the transient in wiseview, with "long detection" being an exeptionally long transient, "unclear" being a transient that is hard to distinguish from background noise and "bright detection" for bright transients. The machine-readable table also contains more columns from TNS and comments for the light curves with two or more epochs detected.
Only a portion of this table is shown here to demonstrate its form and content. A machine-readable version of the full table is available.
A typical type IIn, SN 2010jl-like (e.g., Bevan et al. 2020) long mid-IR detection begins with a sharp increase of the brightness in two stages with the first increase between pre-detection and epoch 1, then the brightness stays constant or fades between epoch 1 and epoch 2. The second sharp increase happens between epoch 2 and epoch 3 and finally the faiding begins. SN 2014ab (see Moriya et al. 2020), SN 2016eei (Gaia16ate), SN 2016cyi (PTSS-16jik), SN 2016ieq (Gaia16buy), SN 2017gas (ASASSN-17kr), SN 2017hcc (ATLAS17lsn) and SN 2017ijn (ATLAS17nhp) are all type IIn with a more or less SN 2010jl-like mid-IR evolution. SN 2018cez (ASASSN-18ls) was classified as a type II, but also shows a similar evolution. The prototype of these kind of SNe (SN 2010jl) shows interactions of SN ejecta and dense circumstellar material. The second increase in IR-brightness is explained with new dust formation (Bevan et al. 2020).
2. Individual SNe
2.1. SN 2016X (ASASSN-16at)
Not many type IIP are known to have long-lived mid-IR transients, with SN 2004et being a well documented case (Kotak et al. 2009). The initial mid-IR flare of SN 2016X is bright in w1 and w2 in the first epoch, with gradual fading. After several epochs the object is only clearly detected in w2 and is still present in the last epoch. Bose et al. (2019) reports double-peaked Hα and Hβ emission lines, that were observed for the first time for a type II. This is attributed to bipolar nickel ejecta embedded in the spherical hydrogen envelope. Utrobin & Chugai (2019) reports the absence of nebular [O I] emission, and an unusual occultation effect due to the internal dust.
2.2. SN 2016gkg
SN 2016gkg is a type IIb supernova with a suspected asymmetric explosion (Kuncarayakti et al. 2020) and it shows a transient bright in w2, with constant fading over about 8 epochs.
2.3. SN 2016ezh (PS16dtm)
TNS lists this transient as a SN II, but it is interpreted as a tidal disruption event (TDE) with described NEOWISE infrared echo (Jiang et al. 2017). The mid-IR light curve is very different from most SNe II: The brightness increases gradually over several epochs, until reaching a plateau.
2.4. SN 2016iot (Gaia16byk)
This type IIL SN (Gall et al. 2017) shows an mid-IR transient that begins with a plateau and only begins to fade in epoch 5. The other type IIL in my list, called SN 2018ktv (ZTF18acwyvet), has only two detected epochs with steady brightness, but it might evolve in a similar way. Long mid-IR detection is known in the Type II-P/II-L Supernova 2013EJ (Mauerhan et al. 2017) and the mid-IR recording begins about 470 days after the detection of 2013EJ, so a direct comparison to the early plateau of SN 2016iot is not possible.
2.5. SN 2017gvb (ATLAS17ldj)
This type IIn (Dong et al. 2019) supernova show a peculiar mid-infrared transient with gradual increase of the brightness in about 5 epochs without a sign of fading. The transient has an amplitude of only about 0.5 mag, much shallower than the TDE PS16dtm. This transient is located far away from the galaxy nucleus.
2.6. SN 2018gn (ASASSN-18ap)
This transient was classified as a SN II with strong host galaxy contamination (Falco et al. 2018) and shows constant increase in mid-infrared over 3 or 4 epochs and is located over the nucleus of the galaxy. A constant increase with a similar high amplitude is also seen at the TDE PS16dtm (see above). ASASSN-18ap is likely a TDE.
2.7. SN 2018hna
This peculiar SN II is described as a 1987A-like supernova (Singh et al. 2019). The first NEOWISE detection 31 days after the discovery shows no excess. The color changes drastically in epoch 2 and is brighter in w2. The light curve shows a fading of w1 in all three epochs, but an increase from epoch 1 to epoch 2 for w2 and then a fading to epoch 3. The first epoch shows about mag and this increases in epoch 2 to
mag.
Facilities: TNS - , CDS - , IRSA - , NEOWISE. -