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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"

35429 results found.

  1. GRB 231117A: AKO Optical Upper Limit
  2. GRB 231117A: afterglow candidate detection from Kinder observations with Lulin observatory
  3. Swift GRB 231117A: Global MASTER-Net observations report
  4. GRB 231117A (short): Glowbug gamma-ray detection
  5. GRB 231117A: ATLAS non-detection of an optical counterpart
  6. Konus-Wind detection of GRB 231117A (short/hard)
  7. GRB 231115A : OHP/T120 optical upper limit
  8. GRB 231115A: optical observations from INAF observatories
  9. GRB 231117A : MITSuME Akeno optical upper limits
  10. GRB 231117A: AGILE detection of a bright short burst
  11. GRB 231117A: Enhanced Swift-XRT position
  12. GRB 231117A: GOTO optical upper limits
  13. GRB 231117A: AstroSat CZTI detection of a bright short burst
  14. GRB 231117A: Swift detection of a bright short burst
  15. GRB 231115A: Non-detection of radio emission with CHIME/FRB
  16. GRB 231111A: Swift/UVOT Detection
  17. MAGIC observation of GRB 231115A, a possible magnetar giant flare
  18. GRB231115A: Liverpool Telescope imaging
  19. GRB 231115A: NuSTAR Follow-Up Observations
  20. GRB 231115A: Swift/BAT-GUANO detection of a short burst
  21. GRB 231115A: Swift-XRT and Swift-UVOT observations
  22. Fermi GRB 231116A: Global MASTER-Net observations report
  23. Konus-Wind detection of GRB 231115A (a probable Magnetar Giant Flare from M82)
  24. GRB 231115A: AGILE/MCAL upper limits
  25. GRB 231115A: Insight-HXMT/HE detection
  26. GRB 231115A: GBM/Fermi Observations of a probable Giant Flare of Magnetar
  27. GRB 231116A: Fermi GBM Final Real-time Localization
  28. GRB 231115A : MITSuME Akeno and Okayama optical upper limits
  29. GRB 231115A: Gaoyazi/GOT follow-up and archival observations
  30. GRB 231115A / AT2023xvj: Updated GIT analysis
  31. GRB 231115A: archival Chandra X-ray observations
  32. GRB 231115A: Upper limits from a neutrino search with IceCube
  33. GRB 231115A: Kinder observations with Lulin observatory
  34. GRB231115A: GRANDMA Observations
  35. GRB 231115A: GOTO pre-burst limits of AT2023xvj
  36. GRB 231115A: Non-detection in low-latency of gravitational waves with LIGO/Virgo/KAGRA
  37. GRB 231115A: pre-burst ZTF upper limits for GRB optical counterpart candidate
  38. GRB 231106A: TESS identification of candidate optical counterpart
  39. GRB 231115A: MASTER optical observations
  40. GRB 231115A (short): Glowbug gamma-ray detection
  41. GRB 231115A: Fermi Observations of a probable Magnetar Giant Flare from M82
  42. GRB 231115A: archival HST observations
  43. GRB 231115A: GROWTH-India discovery of a potential optical counterpart
  44. GRB 231115A: Swift ToO observations
  45. Fermi GRB 231115A: Global MASTER-Net observations report
  46. GRB 231115A: significance of INTEGRAL localization alignment with M82
  47. GRB 231115A: a short hard GRB detected by IBAS, poistionally coincident with M82
  48. GRB 231115A position consistent with M 82 galaxy
  49. GRB 231115A: Fermi GBM Final Real-time Localization
  50. GRB 231111A: Swift-BAT refined analysis
  51. Fermi GRB 231114A: Global MASTER-Net observations report
  52. GRB 231113A (short): Glowbug gamma-ray detection
  53. GRB 231114A (short): Glowbug gamma-ray detection
  54. GRB 231114A: Fermi GBM Final Localization
  55. SGRJ1555-5402: Swift/BAT-GUANO arcminute localization of a SGR flare
  56. LIGO/Virgo/KAGRA S231113bw: Upper limits from Fermi-GBM Observations
  57. GRB 231110A: CALET Gamma-Ray Burst Monitor detection
  58. GRB 231110A: Swift-BAT refined analysis
  59. GRB231111A: MDM 2.4m Hiltner Telescope Observation
  60. GRB 231106A: Glowbug gamma-ray detection
  61. GRB 231111A: Xinglong-2.16m optical observations
  62. GRB 231110A: Swift-UVOT Upper Limits
  63. GRB 231111A: Afterglow redshift from OSIRIS+/GTC
  64. GRB 231104A: VZLUSAT-2 detection
  65. GRB 231111A: TNG tentative redshift
  66. GRB 231110A: Glowbug gamma-ray detection
  67. GRB 231110A: AstroSat CZTI detection
  68. GRB 231111A NUTTelA-TAO / BSTI Early Measurements
  69. GRB 231111A: Leavitt Observatory optical observations
  70. GRB231111A: Optical follow-up observations with Mephisto
  71. GRB 231111A: GMG observation (correction)
  72. GRB 231111A: GMG observation upper limit
  73. GRB 231106B: GRBAlpha detection
  74. GRB 231111A: Osservatorio Astronomico "Nastro Verde" optical observations with detection of an optical counterpart
  75. GRB 231110A: Terskol Zeiss-2000 optical upper limit
  76. GRB 231111A: Swift-XRT refined Analysis
  77. GRB 231111A: Mondy optical observations
  78. GRB 231111A: GECAM-C detection of a long burst (correction)
  79. GRB 231110A: GECAM-B detection (correction)
  80. GRB 231111A: Enhanced Swift-XRT position
  81. GRB 231111A: GECAM-C detection of a long burst
  82. GRB 231110A: GECAM detection
  83. GRB 231110A: GOTO optical upper limits
  84. GRB 231110A: SAO RAS optical observations
  85. GRB 231110A: Swift-XRT afterglow detection
  86. GRB231111A: YAHPT Observations
  87. GRB231111A: GIT confirmation of the optical afterglow
  88. GRB 231111A: MASTER OT earlier detection
  89. GRB 231111A: Nanshan/HMT optical observations
  90. GRB 231111A: Swift detection of a burst with an optical counterpart
  91. GRB231110A: WFST Observation and upper limits
  92. GRB 231110A: Swift detection of a burst
  93. GRB 231109A: Fermi GBM Final Localization
  94. Fermi GRB 231108A: Global MASTER-Net observations report
  95. GRB 231108A: Fermi GBM Final Real-time Localization
  96. GRB 231106A: AstroSat CZTI detection
  97. GRB 231106A: CALET Gamma-Ray Burst Monitor detection
  98. GRB 231104A: Swift-BAT refined analysis
  99. Fermi Gamma-ray Burst Monitor trigger 231107654 / 721064512 is not a GRB
  100. GRB 231104A: FRAM-ORM optical limit

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