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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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').
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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"

914 results found.

  1. IceCube-240327B - IceCube observation of a high-energy neutrino candidate track-like event
  2. GRB 240225B : MITSuME Akeno optical afterglow candidate detection
  3. GRB 240123A : MITSuME Akeno optical afterglow candidate detection
  4. GRB 231215A: AKO Optical Upper Limit
  5. GRB 231215A : MITSuME Akeno optical afterglow candidate detection
  6. GRB 231205B : MITSuME Akeno optical upper limits
  7. GRB 231205B: AKO Optical Upper Limit
  8. GRB 231129A : MITSuME Akeno optical upper limits
  9. GRB 231129C: iTelescope likely optical afterglow AT 2023yph discovery
  10. GRB 231117A : MITSuME Akeno optical afterglow candidate detection
  11. GRB 231117A: AKO Follow-Up Observation
  12. GRB 231117A: AKO Optical Upper Limit
  13. GRB 231117A : MITSuME Akeno optical upper limits
  14. GRB 231115A : MITSuME Akeno and Okayama optical upper limits
  15. GRB 231104A: AKO Upper Limit
  16. GRB 231024A: AKO Optical Counterpart Candidate
  17. GRB 230827.256: AKO Optical follow-up of ZTF23abaanxz (AT 2023qxj)
  18. Swift J1727.8-1613 (GRB 230824A): Montarrenti Observatory photometric observations
  19. GRB 230812B : GRANDMA/Kilonova-Catcher optical afterglow detection and upper limits
  20. GRB 230818A: AKO Upper Limit
  21. GRB 230812B: iTelescope optical upper limit
  22. GRB 230812B: Detected Optical Afterglow Candidate
  23. ZTF23aaoohpy/AT2023lcr: JWST spectroscopy confirmation of an associated type Ic-BL supernova
  24. GRB 230805B : MITSuME Akeno optical upper limits
  25. GRB 230723B: MITSuME Ishigaki optical observation
  26. GRB 230723B: MITSuME Akeno optical afterglow candidate detection
  27. Fermi-LAT gamma-ray observations of IceCube-230524A
  28. GRB 230427A: AKO Upper Limit
  29. GRB 230427A: MITSuME Akeno optical upper limits
  30. GRB 230420A: MITSuME Akeno optical observation
  31. GRB 230307A: iTelescope optical upper limit (likely)
  32. GRB 230328B: OASDG optical observations
  33. GRB 230216A: AKO Upper Limit
  34. Fermi-LAT Gamma-ray Observations of IceCube-Cascade-230109A
  35. Fermi-LAT Gamma-ray Observations of IceCube-Cascade-221229A
  36. GRB 221231A: AKO Upper Limit
  37. GRB 221218A: MITSuME Akeno optical upper limits
  38. GRB 221216A: AKO Upper Limit
  39. Swift GRB221204.45 AKO Upper Limit
  40. GRB 221120A: AKO Telescope Upper Limits
  41. GRB 221110A: GRANDMA observations
  42. GRB 221009A: GRANDMA/Kilonova-Catcher observations
  43. GRB 221028A: AKO Optical Upper Limit
  44. GRB 221028A: HCT optical upper limit
  45. GRB 221028A: MITSuME Okayama optical upper limits
  46. GRB 221009A: spectroscopic confirmation of SN in LBT spectra
  47. GRB 221009A: MITSuME Okayama optical observation
  48. GRB 221009A (Swift J1913.1+1946): iTelescope optical observation
  49. Swift J1913.1+1946: New Photometry
  50. GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations
  51. Swift J1913.1+1946: Early Optical Photometry
  52. Swift J1913.1+1946: Optical photometry
  53. GRB 220930A: MITSuME Akeno optical upper limits
  54. GRB 220701A: MITSuME Akeno optical upper limits
  55. GRB 220623A: iTelescope optical upper limit
  56. GRB 220527A: MITSuME Akeno continued optical observation
  57. GRB 220527A: MITSuME Akeno optical observation
  58. GRB 220521A: MITSuME Akeno optical upper limits
  59. GRB 220521A: SAO RAS optical observations
  60. GRB 220514A: MITSuME Akeno optical observation
  61. GRB 220514A: GRANDMA Optical Afterglow Observations
  62. GRB 220506A: MITSuME Akeno optical upper limits
  63. GRB 220427A: GRANDMA Early Optical Afterglow Detection
  64. GRB 220427A: Swift detection of a burst with an optical counterpart
  65. IceCube-220425A: MASTER: flaring blazar TXS 1742-078 as the possible neutrino source candidate
  66. GRB 220412A: GRANDMA observations
  67. GRB 220408A: HCT optical upper limit
  68. GRB 220412A: MITSuME Akeno optical upper limits
  69. GRB 220412B: MITSuME Akeno optical upper limits
  70. GRB 220408A: GRANDMA observations
  71. GRB 220403B: GRANDMA observations
  72. GRB 220319A: MITSuME Akeno optical upper limits
  73. Fermi-LAT Gamma-ray Observations of IceCube-220317A
  74. GRB 220310A: MITSuME Akeno optical observation
  75. GRB 220311A: MITSuME Akeno optical upper limits
  76. ZTF22aaajecp/AT2022cmc: Terskol observatory optical observations
  77. IceCube Alert 220220.60:NuEm-220220A: MASTER optical possible counterpart
  78. GRB 220118A: MITSuME Akeno optical observation
  79. GRB 220117A: MITSuME Akeno optical upper limits
  80. AMON IC_HAWC NuEm-220116A: No neutrino counterpart detected with ANTARES
  81. GRB 220117B: MITSuME Akeno optical upper limits
  82. GRB 220107B: MITSuME Akeno optical upper limits
  83. GRB 220107A: MITSuME Akeno optical observation
  84. GRB 220101A: iTelescope optical observations
  85. GRB 220101A: OASDG optical observations
  86. GRB 211225A: MITSuME Akeno optical upper limits
  87. GRB 211218A: MITSuME Akeno optical upper limits
  88. GRB 211211A: MITSuME Akeno optical observation
  89. AMON NuEm-211020A: No neutrino counterpart detected with ANTARES
  90. GRB 211129A: MITSuME Akeno optical upper limits
  91. GRB 211023A: optical observations and photometric evidence of supernova
  92. GRB 211023A: SAO RAS optical observations
  93. GRB 211024A: MITSuME Akeno optical observation
  94. GRB 211023B: MITSuME Akeno optical upper limits
  95. GRB 211023A: Terskol optical observations
  96. GRB 210919A: FORS2/VLT observations
  97. AMON IC_HAWC NuEm-211020A: No neutrino counterpart detected with ANTARES
  98. Swift trigger 1078701: MITSuME Akeno optical upper limits
  99. IceCube-20210922A: No optical counterparts found by MITSuME observations
  100. GRB 210919A CAHA 2.2m Observations: Afterglow/Host Galaxy Candidate

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