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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.

Advanced Search Examples (click to copy):

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

16273 results found.

  1. GRB 200529A: LCO Optical Afterglow Detection
  2. GRB 200529A: BOOTES-2/TELMA early optical upper limit
  3. GRB 200524A: SAO RAS optical observations
  4. GRB 200524A: Assy continued optical observations
  5. GRB 200528A: Assy optical upper limit
  6. GRB 200529A: KAIT Optical Afterglow Confirmation
  7. GRB 200529A: NOT optical afterglow
  8. GRB 200528A: NOT optical upper limits
  9. GRB 200528A: Swift/UVOT Upper Limits
  10. GRB 200528A: 1.3m DFOT Optical Upper Limits
  11. GRB 200528A: Nanshan/NEXT optical upper limit
  12. GRB 200528A: MITSuME Akeno optical upper limits
  13. GRB 200524A: Assy optical observations
  14. GRB 200522A: Hubble Space Telescope Near-IR F160W Observations
  15. GRB 200524A: optical upper limits from further MITSuME Akeno observation
  16. GRB 200522A: Gemini North optical imaging
  17. GRB 200524A: CrAO optical observations
  18. GRB 200524A: Kitab observatory afterglow observations
  19. GRB 200524A: KAIT Optical Observations
  20. GRB 200524A: MITSuME Akeno optical observation
  21. GRB 171205A: ATCA observations of late-time radio emission
  22. GRB 200524A: 1.3m DFOT Optical Observation of ZTF20abbiixp
  23. GRB 200524A: Liverpool Telescope observations
  24. GRB 200524A: 3.6m DOT observations of the afterglow candidate ZTF20abbiixp
  25. GRB 200524A: GROWTH-India confirmation of optical afterglow
  26. ZTF Discovery of ZTF20abbiixp: The Likely Optical Afterglow to GRB 200524A
  27. GRB 200522A: LCO Optical Afterglow Detection
  28. GRB 200522A: BOOTES-3/YA optical upper limit
  29. GRB 200522A: Swift/UVOT Upper Limits
  30. GRB 200519A: R-band follow-up from HCT
  31. GRB 200519A: GROWTH-India optical follow-up
  32. GRB 200519A: 1.3m DFOT Optical Afterglow Detection
  33. GRB 200519A: BOOTES-3/YA optical counterpart observations
  34. GRB 200519A: LCO Optical Afterglow Detection
  35. GRB 200519A: iTelescope optical afterglow detection
  36. GRB 200519A: Swift detection of a burst with an optical afterglow
  37. Swift J1818.0-1607: BOOTES-3/YA optical upper limit
  38. GRB 200514B: BALROG localization (Fermi Trigger 611140062 / GRB 200514380)
  39. GRB 200514A: MITSuME Akeno optical upper limits
  40. Optical transient ZTF20aazpphd is unrelated to GRB 200514B
  41. GRB 200512A: LCO Optical Upper Limits
  42. GRB 200512A: Swift/UVOT Upper Limits
  43. Insight-HXMT's continued observation plan for SGR J1935+2154
  44. GRB 200509A: LCO Optical Afterglow Detection
  45. GRB 200509A: Zadko observatory - Gingin optical upper limits
  46. GRB 200509A: Swift detection of a burst with a possible optical counterpart
  47. No optical bursts detected from SGR J1935+2154 by 24 fps observations with Tomo-e Gozen
  48. Fermi GBM trigger 200429866/609886052 is not a GRB
  49. SGR 1935+2154: MASTER optical observations
  50. Gagarin-day GRB 200412B: observations with the 3.6m Devasthal Optical Telescope
  51. GRB 200425A: LCO Optical Upper Limits
  52. GRB 200425A: Swift/UVOT Upper Limits
  53. GRB 200424A: LCO Optical Upper Limit
  54. GRB 200422A: MASTER optical observations
  55. GRB 200410A: Liverpool Telescope First Hour Observations
  56. GRB 200412B: continued Mondy and Terskol optical observations
  57. GRB 200412B: continued Terskol optical observations
  58. GRB 200412B: continued AbAO, Mondy, TSHAO, Terskol optical observations
  59. GRB 200410A: Optical upper limit
  60. GRB 200415A: MASTER imspection and possible localisation
  61. GRB 200412B: continued Tautenburg observations
  62. GRB 200416A: Swift detection of a burst with an optical afterglow
  63. GRB 200412B: Mondy optical observations
  64. GRB 200412B: continued Tautenburg observations
  65. GRB 200412B: MITSuME Akeno optical observation
  66. GRB 200412B: Tautenburg observations
  67. GRB 200412B: contunued AbAO optical observations
  68. GRB 200412B: Xinglong TNT optical observations
  69. GRB 200412B: Tautenburg observations
  70. GRB 200412B: AbAO optical observations
  71. GRB 200412B: Optical afterglow detection with 1.3m DFOT
  72. GRB 200412B: Fermi GBM detection
  73. GRB 200412B: MASTER-Amur Optical Couterpart in Gagarin day!
  74. GRB 200412B: MASTER Optical Couterpart in Gagarin day!
  75. GRB 200411A: Swift/UVOT Upper Limits
  76. GRB 200409A: No detection of radio emission 5 hours post-burst
  77. GRB 200410A: Ondrejov D50 afterglow confirmation
  78. GRB 200410A: Swift detection of a burst with a possible optical counterpart
  79. GRB 200409A: Swift detection of a burst with an optical counterpart
  80. GRB 200405B: LCO Optical Upper Limits
  81. GRB 200325B: Mondy continued observations
  82. GRB 200325B: Optical upper limit
  83. GRB 200325B: Mondy continued observations
  84. GRB 200325B: Mondy continued observations
  85. GRB 200325B: Mondy continued observations
  86. GRB 200325B: Tautenburg observations
  87. GRB 200325B: Fermi GBM observation
  88. GRB 200325B: Swift-XRT and UVOT observations
  89. GRB 200325B: LCO Optical Detection
  90. GRB 200324A: AROMA-N Optical Observation
  91. GRB 200324A:: TSHAO optical upper limit
  92. GRB 200324A: Swift/UVOT Upper Limits
  93. GRB 200324A: LCO Optical Upper Limit
  94. GRB 200324A: Konkoly Obs. optical upper limit
  95. GRB 200324A: NOT optical upper limit
  96. GRB 200324A: Tautenburg observations
  97. GRB 200324A:MITSuME Akeno optical upper limits
  98. GW170817: Continued X-ray emission detected with Chandra at 940 days post-merger
  99. LIGO/Virgo S200316bj: No Counterparts in DDOTI/OAN Optical Observations
  100. LIGO/Virgo S200213t: Continued Swift UVOT and XRT observations of ZTF20aamvmzj (AT2020cja)

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