J/ApJ/949/120 Extragalactic fast blue optical transients from ZTF (Ho+, 2023)
A search for extragalactic fast blue optical transients in ZTF and the rate of
AT2018cow-like transients.
Ho A.Y.Q., Perley D.A., Gal-Yam A., Lunnan R., Sollerman J., Schulze S.,
Das K.K., Dobie D., Yao Y., Fremling C., Adams S., Anand S., Andreoni I.,
Bellm E.C., Bruch R.J., Burdge K.B., Castro-Tirado A.J., Dahiwale A.,
De K., Dekany R., Drake A.J., Duev D.A., Graham M.J., Helou G.,
Kaplan D.L., Karambelkar V., Kasliwal M.M., Kool E.C., Kulkarni S.R.,
Mahabal A.A., Medford M.S., Miller A.A., Nordin J., Ofek E., Petitpas G.,
Riddle R., Sharma Y., Smith R., Stewart A.J., Taggart K., Tartaglia L.,
Tzanidakis A., Winters J.M.
<Astrophys. J., 949, 120 (2023)>
=2023ApJ...949..120H 2023ApJ...949..120H
ADC_Keywords: Transient; Photometry, ugriz; Supernovae; Redshifts;
Spectra, optical; Photometry, infrared; Ultraviolet
Keywords: Transient sources ; Time domain astronomy ; Core-collapse supernovae ;
Surveys
Abstract:
We present a search for extragalactic fast blue optical transients
(FBOTs) during Phase I of the Zwicky Transient Facility (ZTF). We
identify 38 candidates with durations above half-maximum light
1day<t1/2<12days, of which 28 have blue (g-r≲-0.2mag) colors at
peak light. Of the 38 transients (28 FBOTs), 19 (13) can be
spectroscopically classified as core-collapse supernovae (SNe): 11 (8)
H- or He-rich (Type II/IIb/Ib) SNe, 6 (4) interacting (Type IIn/Ibn)
SNe, and 2 (1) H&He-poor (Type Ic/Ic-BL) SNe. Two FBOTs (published
previously) had predominantly featureless spectra and luminous radio
emission: AT2018lug (The Koala) and AT2020xnd (The Camel). Seven
(five) did not have a definitive classification: AT 2020bdh showed
tentative broad Hα in emission, and AT 2020bot showed
unidentified broad features and was 10 kpc offset from the center of
an early-type galaxy. Ten (eight) have no spectroscopic observations
or redshift measurements. We present multiwavelength (radio,
millimeter, and/or X-ray) observations for five FBOTs (three Type Ibn,
one Type IIn/Ibn, one Type IIb). Additionally, we search radio-survey
(VLA and ASKAP) data to set limits on the presence of radio emission
for 24 of the transients. All X-ray and radio observations resulted in
nondetections; we rule out AT2018cow-like X-ray and radio behavior for
five FBOTs and more luminous emission (such as that seen in the Camel)
for four additional FBOTs. We conclude that exotic transients similar
to AT2018cow, the Koala, and the Camel represent a rare subset of
FBOTs and use ZTF's SN classification experiments to measure the rate
to be at most 0.1% of the local core-collapse SN rate.
Description:
The ZTF custom mosaic camera is mounted on the 48-inch Samuel Oschin
Telescope (P48) at Palomar Observatory.
We searched data from ZTF Phase I, i.e., obtained from 2018 March
through 2020 October. For each of the 127,487 field nights, we
searched for transients. After selection cuts, the 38 ZTF transients
with 1d<t1/2,g<12d and well-sampled light curves are listed in
Table 2.
See Sections 2.1 and 2.2.
When available, we added photometry obtained with other facilities:
the IO:O on the Liverpool Telescope (LT), and the Rainbow Camera on
the automated 60-inch telescope at Palomar Observatory (P60).
The final combined light curves are provided in Table 4.
See Section 2.4.
Of the 38 ZTF transients in Table 2, 20 were classified using optical
spectroscopy, and an additional 9 had redshift measurements but no
classification.
Spectra of the transients and their host galaxies were obtained using
a variety of telescopes: the Spectral Energy Distribution Machine
(SEDM), the Alhambra Faint Object Spectrograph and Camera (ALFOSC) on
the Nordic Optical Telescope (NOT), the Double Beam Spectrograph
(DBSP) on the 200-inch Hale telescope at Palomar Observatory, the
Spectrograph for the Rapid Acquisition of Transients (SPRAT) on LT,
the Low Resolution Imaging Spectrometer (LRIS) on the Keck I 10m
telescope, Binospec on the MMT, the Optical System for Imaging and
low-Intermediate-Resolution Integrated Spectroscopy (OSIRIS) on the
Gran Telescopio Canarias (GTC), the Gemini Multi-object Spectrograph
(GMOS) on Gemini North, and the Device Optimized for the LOw
RESolution (DOLORES) on the Telescopio Nazionale Galileo (TNG).
We provide a log of nonpublished spectroscopic observations
(Appendix C, Table 11).
See Section 2.5.
Six of the transients in Table 2 were observed with the UV/Optical
Telescope (UVOT) and X-Ray Telescope (XRT) on board the Neil Gehrels
Swift Observatory. See Section 2.6.
Four transients in Table 2 have published millimeter and/or radio
observations. We also observed an additional four objects with the
IRAM Northern Extended Millimeter Array (NOEMA), the Submillimeter
Array (SMA), and the Karl G. Jansky Very Large Array (VLA).
See Section 2.7.
We obtained host galaxy photometry for all transients with redshift
measurements, provided in Table 9. We retrieved science-ready coadded
images from the Galaxy Evolution Explorer (GALEX) general release 6/7,
the SDSS data release 9 (SDSS DR9), PS1 Data Release 1, the Two Micron
All Sky Survey (2MASS), and preprocessed Wide-field Infrared Survey
Explorer (WISE) images from the unWISE archive.
See Section 2.8.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 109 38 Candidate extragalactic transients from ZTF Phase I
with durations 1d<t1/2,g<12d and well-sampled
light curves
table4.dat 65 4612 Forced photometry of the ZTF transients in Table 2
table9.dat 546 28 Photometry of the host galaxies
table11.dat 51 81 Log of spectroscopic observations of objects
presented in this paper
--------------------------------------------------------------------------------
See also:
VII/233 : 2MASS All-Sky Extended Source Catalog (XSC) (IPAC/UMass, 2003-2006)
V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)
II/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers+, 2016)
II/335 : Revised cat. of GALEX UV sources (GUVcat_AIS GR6+7) (Bianchi+ 2017)
II/363 : The band-merged unWISE Catalog (Schlafly+, 2019)
J/MNRAS/397/1177 : Swift-XRT observations of GRBs (Evans+, 2009)
J/ApJ/741/97 : Light curves of Ibc supernovae (Drout+, 2011)
J/MNRAS/410/166 : Morphological types from Galaxy Zoo 1 (Lintott+, 2011)
J/AJ/144/4 : Dwarf galaxies in the Local Group (McConnachie+, 2012)
J/MNRAS/425/1789 : Berkeley supernova Ia program. I. (Silverman+, 2012)
J/ApJ/763/42 : X-ray emission from 28 SNe (IIn, Ibn; SLSN-I) (Ofek+, 2013)
J/ApJ/769/39 : SN Ibn PS1-12sk optical & NIR light curves (Sanders+, 2013)
J/ApJ/794/23 : Pan-STARRS1 transients optical photometry (Drout+, 2014)
J/ApJ/792/30 : NEOWISE magnitudes for near-Earth objects (Mainzer+, 2014)
J/AJ/147/99 : Spectroscopy of stripped core-collapse SNe (Modjaz+, 2014)
J/A+A/579/A40 : PESSTO catalog (Smartt+, 2015)
J/ApJ/819/35 : LCs of four transients from PTF & SNLS (Arcavi+, 2016)
J/A+A/593/A68 : PTF12os & iPTF13bvn spectra & light curves (Fremling+, 2016)
J/ApJ/851/107 : iPTF 16asu photometry follow-up (Whitesides+, 2017)
J/MNRAS/481/894 : Rapidly evolving transients in the DES (Pursiainen+, 2018)
J/ApJ/880/7 : Census of the Local Universe survey. I. (Cook+, 2019)
J/ApJ/887/169 : UV-Opt light curves of the type Ic SN 2018gep (Ho+, 2019)
J/A+A/631/A147 : Transient processing & analysis using AMPEL (Nordin+, 2019)
J/ApJ/886/152 : ZTF early observations of Type Ia SNe. I. LCs (Yao+, 2019)
J/ApJ/904/155 : gri photometry for 32 kilonovae with ZTF (Andreoni+, 2020)
J/ApJ/895/L23 : Radio obs. of the transient CSS161010 (Coppejans+, 2020)
J/ApJ/905/58 : The local universe with ZTF. I. (De+, 2020)
J/ApJ/895/32 : Zwicky Transient Facility BTS. I. (Fremling+, 2020)
J/ApJ/905/98 : Keck/LRIS optical spectrum of ZTF20aajnksq (Ho+, 2020)
J/ApJ/895/49 : Optical sp. of ZTF18abvkwla and its host galaxy (Ho+, 2020)
J/ApJ/903/132 : Radio & optical obs. of supernova SN2020oi (Horesh+, 2020)
J/ApJ/898/166 : UV to NIR obs. of SN 2019ehk (Jacobson-Galan+, 2020)
J/MNRAS/498/2575 : Rapidly evolving transients with DES (Wiseman+, 2020)
J/ApJ/900/46 : UV, opt & IR light curve of supernova SN2019dge (Yao+, 2020)
J/ApJ/922/247 : ZTF photometric measurements of AT 2018lqh (Ofek+, 2021)
J/ApJ/915/121 : Type Ic SN2018gep phot. & sp. follow-up (Pritchard+, 2021)
J/ApJ/908/232 : SN 2020bvc optical and near-IR spectra (Rho+, 2021)
J/ApJS/255/29 : PTF core-collapse SN host-galaxy sample. I. (Schulze+, 2021)
J/MNRAS/503/3931 : Core-collapses supernovae host galaxies (Taggart+, 2021)
J/ApJ/910/42 : LCs & spectroscopic observations of AT2018cow (Xiang+, 2021)
J/ApJ/924/55 : UV and optical obs. of type Ic SN 2020oi (Gagliano+, 2022)
J/ApJ/927/10 : Photometry follow-up of 3 core-collapse SNe (Irani+, 2022)
J/ApJ/926/125 : Fast-evolving SNIbn with LCO & FLOYDS (Pellegrino+, 2022)
J/ApJ/927/180 : Type Icn SN2021csp photometry & spectra (Perley+, 2022)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- ZTF ZTF identifier
11- 11 A1 --- f_ZTF [Mm] Flag on ZTF (1)
13- 14 I2 h RAh Hour of Right Ascension (J2000)
16- 17 I2 min RAm Minute of Right Ascension (J2000)
19- 23 F5.2 s RAs Second of Right Ascension (J2000)
25- 25 A1 --- DE- Sign of the Declination (J2000)
26- 27 I2 deg DEd Degree of Declination (J2000)
29- 30 I2 arcmin DEm Arcminute of Declination (J2000)
32- 35 F4.1 arcsec DEs Arcsecond of Declination (J2000)
37- 47 A11 --- Name IAU identifier
49- 56 F8.2 d MJD [58230.3/59141.5] Modified Julian Date of peak
58- 62 F5.2 mag Pmag [14/19.8] Peak apparent AB magnitude
64- 67 F4.2 mag e_Pmag [0.01/0.2] Uncertainty in Pmag
69- 72 F4.1 d t0.5g [3.3/11.9] Duration, t1/2,g
74- 76 F3.1 d e_t0.5g [0.1/2] Uncertainty in t0.5g
78- 81 F4.1 mag g-r [-0.7/0.4] The (g-r) color
83- 83 A1 --- f_g-r [d] Flag on g-r (2)
85- 91 F7.5 --- z [0.005/0.3]? Spectroscopic redshift
93-100 A8 --- Class Classification (3)
102-103 A2 --- f_Class [Dd ] Flag on Class (4)
105-109 A5 --- Ref Reference(s) (5)
--------------------------------------------------------------------------------
Note (1): Flag on ZTF as follows:
M = Multiwavelength observations published as part of this paper.
m = Previously published multiwavelength (UV, X-ray, and/or radio)
observations available.
Note (2): Flag on g-r as follows:
d = The closest r-band detection was 2d from the peak g-band measurement;
for all other sources in the table, the g and r measurements were
within 1d of each other.
Note (3): For a detailed review of the SN classifications in this table,
see Gal-Yam A. (2017hsn..book..195G 2017hsn..book..195G) and Smith+ (2017MNRAS.466.3021S 2017MNRAS.466.3021S).
Briefly, Type II SNe have hydrogen P-Cygni features and Type Ib
and Ic SNe lack hydrogen and helium, respectively. Type Ic-BL SNe
have particularly broad P-Cygni features indicative of large ejecta
velocities (v>20000km/s). Type Ibn and Type IIn SNe have spectra
dominated by emission lines of helium and hydrogen, respectively.
Note (4): Flag on class as follows:
dd = Feat. is a high-S/N featureless spectrum at peak light.
RL is radio loud.
D = UB is unidentified broad features in spectrum.
Note (5): References as follows:
1 = Karamehmetoglu et al. (2021A&A...649A.163K 2021A&A...649A.163K)
2 = Yao et al. (2020ApJ...900...46Y 2020ApJ...900...46Y)
3 = Ho et al. (2019ApJ...887..169H 2019ApJ...887..169H)
4 = Pritchard et al. (2021ApJ...915..121P 2021ApJ...915..121P)
5 = Tonry et al. (2018TNSTR1379....1T 2018TNSTR1379....1T)
6 = Fremling et al. (2018TNSCR1567....1F 2018TNSCR1567....1F)
7 = Ho et al. (2020ApJ...895...49H 2020ApJ...895...49H)
8 = Prentice et al. (2020MNRAS.499.1450P 2020MNRAS.499.1450P)
9 = Nordin et al. (2019TNSTR1258....1N 2019TNSTR1258....1N)
10 = Nordin et al. (2019TNSTR.543....1N 2019TNSTR.543....1N)
11 = Prentice et al. (2019TNSCR.567....1P 2019TNSCR.567....1P)
12 = Pellegrino et al. (2022ApJ...926..125P 2022ApJ...926..125P)
13 = Nordin et al. (2019TNSTR.720....1N 2019TNSTR.720....1N)
14 = Tonry et al. (2019TNSTR1194....1T 2019TNSTR1194....1T)
15 = Wiseman et al. (2019TNSAN..56....1W 2019TNSAN..56....1W)
16 = Tonry et al. (2019TNSTR1694....1T 2019TNSTR1694....1T)
17 = Chambers et al. (2019TNSTR1814....1C 2019TNSTR1814....1C)
18 = Forster (2019TNSTR1906....1F 2019TNSTR1906....1F)
19 = Forster et al. (2021AJ....161..242F 2021AJ....161..242F)
20 = Dahiwale & Fremling (2019TNSCR2407....1D 2019TNSCR2407....1D)
21 = Tonry et al. (2019TNSTR2014....1T 2019TNSTR2014....1T)
22 = Nordin et al. (2019TNSTR2389....1N 2019TNSTR2389....1N)
23 = Horesh et al. (2020ApJ...903..132H 2020ApJ...903..132H)
24 = Rho et al. (2021ApJ...908..232R 2021ApJ...908..232R)
25 = Gagliano et al. (2022ApJ...924...55G 2022ApJ...924...55G)
26 = Smith et al. (2020TNSAN..39....1S 2020TNSAN..39....1S)
27 = Forster et al. (2020TNSTR.278....1F 2020TNSTR.278....1F)
28 = Nordin et al. (2020TNSTR.356....1N 2020TNSTR.356....1N)
29 = Tonry et al. (2020TNSTR1158....1T 2020TNSTR1158....1T)
30 = Angus (2020TNSCR1392....1A 2020TNSCR1392....1A)
31 = Dahiwale & Fremling (2020TNSCR1756....1D 2020TNSCR1756....1D)
32 = De (2020TNSTR1294....1D 2020TNSTR1294....1D)
33 = Marques-Chaves et al. (2020TNSTR1781....1M 2020TNSTR1781....1M)
34 = Forster et al. (2020TNSTR1380....1F 2020TNSTR1380....1F)
35 = Chambers et al. (2020TNSTR3320....1C 2020TNSTR3320....1C)
36 = Forster et al. (2020TNSTR2542....1F 2020TNSTR2542....1F)
37 = Perley et al. (2021MNRAS.508.5138P 2021MNRAS.508.5138P)
38 = Siebert et al. (2020TNSCR3121....1S 2020TNSCR3121....1S)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Name SN identifier
13 A1 --- Filt [ugriz] Filter used
15- 24 F10.2 d JD Julian Date of the observation
26- 33 F8.2 uJy Flux [-106/10927] Flux density in Filt
35- 42 F8.2 uJy e_Flux [0.7/14072] Uncertainty in Flux
44 A1 --- l_mag [<] 5-sigma upper limit on mag
46- 50 F5.2 mag mag [11.78/23.1] Apparent AB magnitude in Filt
not corrected for Milky Way extinction
53- 56 F4.2 mag e_mag [0.01/0.8]? Uncertainty in mag
58- 65 A8 --- Tel Telescope identifier (1)
--------------------------------------------------------------------------------
Note (1): Telescope as follows:
LT+IOO = Liverpool 2m Telescope (373 occurrences)
P48 = Samuel Oschin Telescope 48-inch at Palomar (4154 occurrences)
P60+SEDM = 60-inch Telescope at Palomar (85 occurrences)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table9.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Seq [0/27] Index number
4- 14 A11 --- Name SN identifier
16- 20 F5.3 --- z [0.005/0.3] Spectroscopic redshift
22- 31 F10.6 mag FUVmag [0.007/32.5]?=-99 GALEX FUV band AB magnitude;
uncorrected from reddening
33- 42 F10.6 mag e_FUVmag [0.0009/0.5]?=-99 Uncertainty in FUVmag
44- 52 F9.5 mag NUVmag [0.01/55]?=-99 GALEX NUV band AB magnitude;
uncorrected from reddening
54- 64 F11.7 mag e_NUVmag [0.0008/1]?=-99 Uncertainty in NUVmag
66- 74 F9.5 mag UVW2mag [0.037/0.038]?=-99 Swift UVW2 band AB
magnitude; uncorrected from reddening
76- 84 F9.5 mag e_UVW2mag [0.00405]?=-99 Uncertainty in UVW2mag
86- 94 F9.5 mag UVM2mag [0.035/0.036]?=-99 Swift UVM2 band AB
magnitude; uncorrected from reddening
96- 105 F10.6 mag e_UVM2mag [0.004554]?=-99 Uncertainty in UVM2mag
107- 115 F9.5 mag UVW1mag [0.030/0.031]?=-99 Swift UVW1 band AB
magnitude; uncorrected from reddening
117- 126 F10.6 mag e_UVW1mag [0.004667]?=-99 Uncertainty in UVW1mag
128- 136 F9.5 mag Umag [0.04795]?=-99 Swift U band AB magnitude;
uncorrected from reddening
138- 147 F10.6 mag e_Umag [0.006914]?=-99 Uncertainty in Umag
149- 157 F9.5 mag Bmag [0.06149]?=-99 Swift B band AB magnitude;
uncorrected from reddening
159- 167 F9.5 mag e_Bmag [0.01139]?=-99 Uncertainty in Bmag
169- 176 F8.4 mag Vmag [0.1526]?=-99 Swift V band AB magnitude;
uncorrected from reddening
178- 186 F9.5 mag e_Vmag [0.02999]?=-99 Uncertainty in Vmag
188- 197 F10.6 mag S-umag [0.008/173]?=-99 SDSS u band AB magnitude;
uncorrected from reddening
199- 208 F10.6 mag e_S-umag [0.003/6]?=-99 Uncertainty in S-umag
210- 220 F11.7 mag S-gmag [0.0004/486]?=-99 SDSS g band AB magnitude;
uncorrected from reddening
222- 232 F11.7 mag e_S-gmag [0.0001/8.5]?=-99 Uncertainty in S-gmag
234- 244 F11.7 mag S-rmag [0/807]?=-99 SDSS r band AB magnitude;
uncorrected from reddening
246- 256 F11.7 mag e_S-rmag [0.0002/21]?=-99 Uncertainty in S-rmag
258- 267 F10.5 mag S-imag [0.01/1092]?=-99 SDSS i band AB magnitude;
uncorrected from reddening
269- 278 F10.6 mag e_S-imag [0.002/33]?=-99 Uncertainty in S-imag
280- 289 F10.5 mag S-zmag [0/1287]?=-99 SDSS z band AB magnitude;
uncorrected from reddening
291- 301 F11.7 mag e_S-zmag [0.0002/55]?=-99 Uncertainty in S-zmag
303- 311 F9.5 mag P-gmag [0.01/16.3]?=-99 PANSTARRS g band AB
magnitude; uncorrected from reddening
313- 323 F11.7 mag e_P-gmag [0.0008/0.4]?=-99 Uncertainty in P-gmag
325- 333 F9.5 mag P-rmag [0.01/26.2]?=-99 PANSTARRS r band AB
magnitude; uncorrected from reddening
335- 344 F10.6 mag e_P-rmag [0.001/0.4]?=-99 Uncertainty in P-rmag
346- 354 F9.5 mag P-imag [0.01/33]?=-99 PANSTARRS i band AB magnitude;
uncorrected from reddening
356- 366 F11.7 mag e_P-imag [0.0008/0.7]?=-99 Uncertainty in P-imag
368- 376 F9.5 mag P-zmag [0.02/38.2]?=-99 PANSTARRS z band AB
magnitude; uncorrected from reddening
378- 387 F10.6 mag e_P-zmag [0.002/0.6]?=-99 Uncertainty in P-zmag
389- 397 F9.5 mag P-ymag [0.01/45.5]?=-99 PANSTARRS y band AB
magnitude; uncorrected from reddening
399- 407 F9.5 mag e_P-ymag [0.01/1.5]?=-99 Uncertainty in P-ymag
409- 417 F9.4 mag Jmag [0.19/1542]?=-99 2MASS J band AB magnitude;
uncorrected from reddening
419- 427 F9.5 mag e_Jmag [0.06/71.1]?=-99 Uncertainty in Jmag
429- 437 F9.4 mag Hmag [0.2/1703]?=-99 2MASS H band AB magnitude;
uncorrected from reddening
439- 447 F9.5 mag e_Hmag [0.09/78.5]?=-99 Uncertainty in Hmag
449- 457 F9.4 mag Ksmag [0.2/1434]?=-99 2MASS Ks band AB magnitude;
uncorrected from reddening
459- 466 F8.4 mag e_Ksmag [0.1/66.1]?=-99 Uncertainty in Ksmag
468- 476 F9.5 mag W1mag [0.01/34]?=-99 WISE W1 band AB magnitude;
uncorrected from reddening
478- 487 F10.6 mag e_W1mag [0.005/0.3]?=-99 Uncertainty in W1mag
489- 498 F10.6 mag W2mag [0.004/20.4]?=-99 WISE W2 band AB magnitude;
uncorrected from reddening
500- 509 F10.6 mag e_W2mag [0.005/0.3]?=-99 Uncertainty in W2mag
511- 518 F8.4 mag W3mag [0.2/12.4]?=-99 WISE W3 band AB magnitude;
uncorrected from reddening
520- 528 F9.5 mag e_W3mag [0.03/0.2]?=-99 Uncertainty in W2mag
530- 537 F8.4 mag W4mag [0.3/15]?=-99 WISE W4 band AB magnitude;
uncorrected from reddening
539- 546 F8.4 mag e_W4mag [0.2/0.4]?=-99 Uncertainty in W4mag
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table11.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Name Target name (1)
13- 22 A10 "Y/M/D" Date Date of observation (UT)
24- 32 A9 --- TType Target type: "Transient" or "Host"
34- 36 I3 --- Phase [-4/290] Phase given with respect to the
observed maximum of the g-band light curve
38- 49 A12 --- Tel Telescope
51 I1 --- Ref [1/3]? Reference (2)
--------------------------------------------------------------------------------
Note (1): Our requirement of multiband photometry excludes some known rapidly
evolving transients, including the Type Ibn SN 2019aajs
(Kool et al. 2023, in preparation).
See Section 2 and Appendix.
Note (2): Reference as follows:
1 = Gromadzki et al. 2018TNSCR1410....1G 2018TNSCR1410....1G
2 = Smith et al. 2020TNSAN..39....1S 2020TNSAN..39....1S
3 = Siebert et al. 2020TNSCR3121....1S 2020TNSCR3121....1S
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 24-Jul-2025