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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').
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"

5038 results found.

  1. GRB 220408A: GRANDMA observations
  2. Fermi GRB 220411A: Global MASTER-Net observations report
  3. GRB 220403B: 1.3m DFOT Optical upper limit
  4. GRB 220408B: AstroSat CZTI detection
  5. ZTF22aaajecp/AT2022cmc: continued optical observations (Mondy, SAO RAS, CrAO)
  6. IceCube Alert 220405.93: Global MASTER-Net observations report
  7. IceCube Alert 220405.21: Global MASTER-Net observations report
  8. GRB 220403B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  9. GRB 220403B: Swift-XRT refined Analysis
  10. Fermi GRB 220403A: Global MASTER-Net observations report
  11. Konus-Wind observation of GRB 220320A
  12. GRB 220325A: Swift-XRT refined Analysis
  13. GRB 220324A: AstroSat CZTI detection
  14. GRB 220319A: MITSuME Akeno optical upper limits
  15. GRB 220319A: Swift-XRT refined Analysis
  16. GRB 220310A: MITSuME Akeno optical observation
  17. IceCube-220317A: MASTER Global Robotic Net optical observations
  18. GRB 220311A: MITSuME Akeno optical upper limits
  19. Konus-Wind detection of GRB 220310A
  20. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, possible photometric evidence of SN
  21. IceCube-220306A: No significant detection in HAWC
  22. GRB 220306B: Swift-XRT refined Analysis
  23. Swift GRB 220306B: Global MASTER-Net observations report
  24. GRB 220305A: Swift-XRT refined Analysis
  25. Fermi GRB 220306A: Global MASTER-Net observations report
  26. IceCube Alert 220304.74: Global MASTER-Net observations report
  27. Swift resumes autonomous slewing
  28. IceCube-220225A: Upper limits from a search for additional neutrino events in IceCube
  29. ZTF22aaajecp/AT2022cmc: Mondy optical observations
  30. Konus-Wind observation of GRB 220219B
  31. GRB 220222B: Fermi GBM Final Real-time Localization
  32. Fermi Gamma-ray Burst Monitor trigger 667074291/220220767 is not a GRB
  33. IceCube Alert 220220.60: Global MASTER-Net observations report
  34. Fermi trigger No 666962499: Global MASTER-Net observations report
  35. Fermi GRB 220211A: Global MASTER-Net observations report
  36. Fermi-LAT Gamma-ray Observations of IceCube-220205A
  37. GRB 211227A: Konus-Wind detection and joint Konus-Wind+Swift-BAT spectral analysis
  38. Fermi GRB 220131A: Global MASTER-Net observations report
  39. Fermi trigger No 664738369: Global MASTER-Net observations report
  40. GRB 220124A: AstroSat CZTI detection of a bright long GRB
  41. IPN triangulation of GRB 211226A
  42. GRB 220118A: MITSuME Akeno optical observation
  43. GRB 220117A: MITSuME Akeno optical upper limits
  44. GRB 220117A: Swift-BAT refined analysis
  45. GRB 220117B: Swift-XRT refined Analysis
  46. GRB 220117A: Swift-XRT refined Analysis
  47. GRB 220117B: MITSuME Akeno optical upper limits
  48. GRB 220117A: Swift detection of a burst
  49. Fermi trigger No 663966693: Global MASTER-Net observations report
  50. Fermi trigger No 663927396: Global MASTER-Net observations report
  51. Fermi trigger No 663763320: Global MASTER-Net observations report
  52. Fermi GRB 220111A: Global MASTER-Net observations report
  53. Konus-Wind detection of GRB 220107A
  54. GRB 220107B: MITSuME Akeno optical upper limits
  55. GRB 220107A: MITSuME Akeno optical observation
  56. GRB 220107A: Swift-XRT afterglow detection
  57. GRB 211229B: Fermi GBM observation
  58. GRB 220101A: Swift-XRT refined Analysis
  59. GRB 211227A: Swift-XRT refined Analysis
  60. Konus-Wind detection of the intermediate flare from SGR 1935+2154
  61. GRB 211225A: MITSuME Akeno optical upper limits
  62. GRB 211225A/MAXI J0827-071: MAXI/GSC detection
  63. Fermi trigger No 662084433: Global MASTER-Net observations report
  64. GRB 211224A: Fermi GBM Final Real-time Localization
  65. Fermi trigger No 662010159: Global MASTER-Net observations report
  66. AGILE observations of a bright burst from SGR 1935+2154
  67. Swift GRB 211223C: Global MASTER-Net observations report
  68. GRB 211218A: MITSuME Akeno optical upper limits
  69. GRB 211221A: MeerLICHT optical limits
  70. GRB 211221A: Swift detection of a burst
  71. GRB 211211A: MMT/MMIRS Observations Indicate Fading of K-band Source
  72. Fermi trigger No 661417475: Global MASTER-Net observations report
  73. GRB 211211A: NOT optical spectroscopy
  74. GRB 211211A: MITSuME Akeno optical observation
  75. GRB 211211A: Swift-XRT refined Analysis
  76. Fermi GRB 211211B: Global MASTER-Net observations report
  77. GRB 211207A: Swift/UVOT Detection
  78. Fermi trigger No 660868196: Global MASTER-Net observations report
  79. IceCube-211208A: No significant detection in HAWC
  80. GRB 211130A: MeerLICHT identification of possible afterglow candidate
  81. IceCube-211208A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  82. GRB 211207A: Swift-XRT refined Analysis
  83. Swift GRB 211207A: Global MASTER-Net observations report
  84. GRB 211207A: Swift detection of a burst with an optical counterpart
  85. IPN triangulation of GRB 211204C
  86. Fermi GRB 211204B: Global MASTER-Net observations report
  87. GRB 211124A: Fermi GBM Observation
  88. IPN triangulation of GRB 211130A
  89. GRB 211129A: Swift-XRT refined Analysis
  90. IceCube-211125A: Upper limits from a search for additional neutrino events in IceCube
  91. IPN triangulation of GRB 211118A
  92. GRB 211129A: MITSuME Akeno optical upper limits
  93. Konus-Wind detection of GRB 211120A
  94. Chandra observations of GRB 210905A
  95. IceCube-211123A: Upper limits from a search for additional neutrino events in IceCube
  96. IceCube Alert 211123.60: Global MASTER-Net observations report
  97. Fermi trigger No 659413798: Global MASTER-Net observations report
  98. Fermi trigger No 659183098: Global MASTER-Net observations report
  99. Fermi trigger No 658971499: Global MASTER-Net observations report
  100. IceCube-211116A: Upper limits from a search for additional neutrino events in IceCube

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