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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

21113 results found.

  1. Fermi trigger No 606614927: Global MASTER-Net observations report
  2. Chandra observations of GW170817 at 2.5 years since merger (All epochs 4 of 4)
  3. Fermi trigger No 606263732: Global MASTER-Net observations report
  4. GW170817: Continued X-ray emission detected with Chandra at 940 days post-merger
  5. LIGO/Virgo S200316bj : No significant candidates in TAROT - FRAM - GRANDMA observations.
  6. LIGO/Virgo S200316bj: Upper limits from Insight-HXMT/HE observations
  7. LIGO/Virgo S200316bj: no counterpart candidate in SVOM/GWAC observations
  8. LIGO/Virgo S200316bj: Upper limits from CALET observations
  9. LIGO/Virgo S200316bj: No counterpart candidates in Fermi-LAT observations
  10. LIGO/Virgo S200316bj: No Counterparts in DDOTI/OAN Optical Observations
  11. LIGO/Virgo S200316bj: no counterpart candidates in the Swift/BAT observations
  12. LIGO/Virgo S200213t: Continued Swift UVOT and XRT observations of ZTF20aamvmzj (AT2020cja)
  13. LIGO/Virgo S200316bj: upper limits from AGILE/GRID observations
  14. LIGO/Virgo S200316bj: upper limits from AGILE/MCAL observations
  15. LIGO/Virgo S200316bj: Upper limits from Fermi-GBM Observations
  16. Fermi trigger No 606098435: Global MASTER-Net observations report
  17. LIGO/Virgo S200316bj: Coverage and upper limits from MAXI/GSC observations
  18. LIGO/Virgo S200316bj: Global MASTER-Net observations report
  19. Fermi trigger No 605789837: Global MASTER-Net observations report
  20. SGR Swift J1818.0-1607: BOOTES-4/MET optical limit
  21. Fermi trigger No 605756501: Global MASTER-Net observations report
  22. Swift GRB200312.89: Global MASTER-Net observations report
  23. Fermi trigger No 605632577: Global MASTER-Net observations report
  24. LIGO/Virgo S200311bg: No significant counterpart candidates in Fermi-LAT observations
  25. LIGO/Virgo S200224ca: DESGW Summary of DECam Observations
  26. GRB 200311A: AGILE/MCAL and scientific ratemeters observations
  27. LIGO/Virgo S200311bg: Coverage and upper limits from MAXI/GSC observations
  28. Chandra observations of GW170817 ~ 2.5 years since merger (epoch 1 of 4)
  29. GRB 200306C: ALMA 3mm upper limit
  30. GRB 200306C: Swift/UVOT Detection
  31. GRB 200306A: Swift/UVOT Upper Limits
  32. Fermi trigger No 605309224: Global MASTER-Net observations report
  33. GRB 200306A: RATIR Optical Observations
  34. GRB 200306C: VIRT optical upper limits
  35. GRB200306C: First Hour Liverpool Telescope Observations
  36. GRB 200306C: OSN 1.5m afterglow detection
  37. GRB 200306C: Liverpool Telescope observations
  38. GRB 200306C: SAO RAS observations of OT
  39. GRB 200306C: GOTO upper limits
  40. LIGO/Virgo S200302c: No notable candidates in GOTO imaging
  41. Swift GRB200306.95: Global MASTER-Net observations report
  42. LIGO/Virgo S200302c : No significant candidates in FRAM - TAROT - GRANDMA observations.
  43. Swift GRB200306.01: Global MASTER-Net observations report
  44. GRB 200228B: continued optical observations
  45. LIGO/Virgo S200225q: No notable candidates in GOTO imaging
  46. GRB200210A AstroSat observations
  47. LIGO/Virgo S200302c: Upper limits from Insight-HXMT/HE observations
  48. GRB 200303A: NOT optical observations
  49. GRB 200303A: Swift/UVOT Upper Limits
  50. GRB 200303A: GOTO observations upper limit
  51. GRB 200303A: Optical limit from CAHA
  52. LIGO/Virgo S200302c: No transient candidates in CALET observations
  53. GRB 200219C: VLA Detection
  54. Swift GRB200303.11: Global MASTER-Net observations report
  55. Fermi trigger No 604895668: Global MASTER-Net observations report
  56. LIGO/Virgo S200224ca: No counterpart candidates in TOROS observations
  57. LIGO/Virgo S200302c: No significant counterpart candidates in Fermi-LAT observations
  58. LIGO/Virgo S200302c: No counterpart candidates in KAIT observations
  59. LIGO/Virgo S200302c: no counterpart candidates in the Swift/BAT observations
  60. LIGO/Virgo S200302c: No counterpart candidates in HAWC observations
  61. LIGO/Virgo S200302c: Upper limits from Fermi-GBM Observations
  62. LIGO/Virgo S200302c: upper limits from AGILE/MCAL observations
  63. LIGO/Virgo S200302c: Coverage and upper limits from MAXI/GSC observations
  64. LIGO/Virgo S200302c: Global MASTER-Net observations report
  65. GRB 200228B: Mondy, TSHAO, AbAO and CrAO optical observations, afterglow candidate
  66. LIGO/Virgo S200225q : No significant candidates in TAROT - FRAM - GRANDMA observations.
  67. GRB 200228B: RATIR Optical Observations
  68. Swift GRB 200228B: Global MASTER-Net observations report
  69. GRB 200228B: Swift/UVOT Upper Limits
  70. GRB 200228B: RATIR Optical Observations
  71. GRB 200227A: RATIR Optical Observations
  72. GRB 200228B: KAIT Optical Upper Limit
  73. LIGO/Virgo S200213t: No significant EM counterparts identified from continued GECKO observation of host galaxy candidates
  74. Fermi-LAT Gamma-ray Observations of IceCube-200227A
  75. Fermi trigger No 604565918: Global MASTER-Net observations report
  76. IceCube-200227A : Upper limits from Insight-HXMT/HE observations
  77. GRB 200219A: ATCA 5/9 GHz radio observations
  78. GRB 200227A: Swift/UVOT Upper Limits
  79. IceCube-200227A: Upper limits from Fermi-GBM Observations
  80. LIGO/Virgo S200224ca : No significant candidates in TAROT - FRAM - GRANDMA observations
  81. LIGO/Virgo S200224ca: Upper limits from CALET observations.
  82. LIGO/Virgo S200224car: GRAWITA VST-ESO PARANAL observations.
  83. LIGO/Virgo S200224ca: DESGW Optical counterpart candidates from DECam
  84. LIGO/Virgo S200219ac: Upper limits from Konus-Wind observations
  85. LIGO/Virgo S200213t: Upper limits from Konus-Wind observations
  86. LIGO/Virgo S200208q: Upper limits from Konus-Wind observations
  87. LIGO/Virgo S200225q: no counterpart candidate in SVOM/GWAC observations
  88. LIGO/Virgo S200225q: Upper limits from Insight-HXMT/HE observations
  89. LIGO/Virgo S200224ca: Upper limits from Insight-HXMT/HE observations
  90. LIGO/Virgo S200225q: no counterpart candidates in the Swift/BAT observations
  91. LIGO/Virgo S200224ca: no counterpart candidates in the Swift/BAT observations
  92. GRB 200224B: DDOTI/OAN optical observations report
  93. LIGO/Virgo S200224ca: No counterpart candidates in KAIT observations
  94. LIGO/Virgo S200224ca: No Counterparts in DDOTI/OAN Optical Observations
  95. LIGO/Virgo S200224ca: GRAWITA-Campo Imperatore observations.
  96. LIGO/Virgo S200225q: Upper limits from Fermi-GBM Observations
  97. Fermi trigger No 604231129: Global MASTER-Net observations report
  98. LIGO/Virgo S200225q: No counterpart candidates in Fermi-LAT observations
  99. LIGO/Virgo S200225q: upper limits from AGILE/GRID observations
  100. LIGO/Virgo S200224ca: Subaru/Hyper Suprime-Cam follow-up observations

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