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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"

32775 results found.

  1. GRB 231118A: ATCA detection of radio counterpart
  2. GRB 231117A: Swift/UVOT late time observations
  3. GRB 231117A: GTC Near-Infrared Observations
  4. GRB 231117A: Swift-BAT refined analysis
  5. GRB 231118A: GRBAlpha detection
  6. LIGO/Virgo/KAGRA S231119u: Updated Sky localization and Source Classification
  7. LIGO/Virgo/KAGRA S231118ab: Updated Sky localization and Source Classification
  8. LIGO/Virgo/KAGRA S231118d: Updated Sky localization and Source Classification
  9. GRB 231118A: VZLUSAT-2 detection
  10. GRB 231117A: AMI-LA radio observations
  11. GRB 231118A: Swift-BAT refined analysis
  12. Konus-Wind detection of GRB 231020A
  13. GRB 231117A: LDT Confirmation of Optical Fading
  14. GRB 231117A: Wendelstein Confirmation of Fading of the Optical Afterglow
  15. GRB 231118B: CALET Gamma-Ray Burst Monitor detection
  16. GRB 231117A: CALET Gamma-Ray Burst Monitor detection
  17. 231118A: Swift-UVOT Detection
  18. GRB231117A: Swift-UVOT detection
  19. GRB 231117A : MITSuME Akeno optical afterglow candidate detection
  20. GRB 231118B: Fermi GBM observation
  21. GRB 231118A: Fermi GBM observation
  22. GRB 231118A: MeerLICHT afterglow detection
  23. GRB 231117A: OHP/T120 optical observations
  24. GRB 231118A: VLT/X-shooter redshift
  25. GRB 231117A: Pan-STARRS1 follow-up confirms rapid fading
  26. LIGO/Virgo/KAGRA S231119u: Identification of a GW compact binary merger candidate
  27. GRB 231117A: MAAO 0.7-m telescope optical upper limit
  28. GRB 231117A: AKO Follow-Up Observation
  29. GRB 231117A: GECAM-C detection
  30. GRB 231118A: AstroSat CZTI detection
  31. GRB 231115A: Upper limit from CALET Gamma-Ray Burst Monitor
  32. GRB 231117A: 10 GHz VLA detection
  33. GRB 231118A: Las Cumbres optical detection
  34. GRB 231118A: LCOGT Optical Observations
  35. GRB 231118A: MASTER OT observation
  36. GRB 231118A: Continued Skynet Observations
  37. GRB 231117A: Kinder observations with Lulin observatory for AT 2023yba without fading in r band
  38. GRB 231117A: SOAR/Goodman imaging of the afterglow
  39. GRB 231117A: Lowell Discovery Telescope Observations
  40. GRB 231117A: ePESSTO+ host galaxy redshift confirmation
  41. GRB 231117A: ATCA detection of a radio counterpart
  42. LIGO/Virgo/KAGRA S231118an: Identification of a GW compact binary merger candidate
  43. GRB 231117A: GRBAlpha detection
  44. LIGO/Virgo/KAGRA S231118ab: Identification of a GW compact binary merger candidate
  45. GRB 231117A: Keck spectroscopy of afterglow candidate
  46. GRB 231115A: Wendelstein Optical/Infrared Observations
  47. GRB 231115A: JinShan optical upper limits
  48. LIGO/Virgo/KAGRA S231118d: Identification of a GW compact binary merger candidate
  49. GRB 231117A: GIT optical follow-up
  50. GRB 231117A: LT observations consistent with fading
  51. GRB 231117A: Keck observations indicate presence of optical afterglow in z~0.3-0.5 galaxy
  52. GRB 231117A: REM optical and NIR early-time observations
  53. GRB 231117A: AKO Optical Upper Limit
  54. GRB 231117A: afterglow candidate detection from Kinder observations with Lulin observatory
  55. Swift GRB 231117A: Global MASTER-Net observations report
  56. GRB 231117A (short): Glowbug gamma-ray detection
  57. GRB 231117A: ATLAS non-detection of an optical counterpart
  58. Konus-Wind detection of GRB 231117A (short/hard)
  59. GRB 231115A : OHP/T120 optical upper limit
  60. GRB 231115A: optical observations from INAF observatories
  61. GRB 231117A : MITSuME Akeno optical upper limits
  62. GRB 231117A: AGILE detection of a bright short burst
  63. GRB 231117A: GOTO optical upper limits
  64. GRB 231117A: AstroSat CZTI detection of a bright short burst
  65. GRB 231115A: Non-detection of radio emission with CHIME/FRB
  66. GRB 231111A: Swift/UVOT Detection
  67. MAGIC observation of GRB 231115A, a possible magnetar giant flare
  68. GRB231115A: Liverpool Telescope imaging
  69. GRB 231115A: NuSTAR Follow-Up Observations
  70. GRB 231115A: Swift/BAT-GUANO detection of a short burst
  71. GRB 231115A: Swift-XRT and Swift-UVOT observations
  72. Fermi GRB 231116A: Global MASTER-Net observations report
  73. Konus-Wind detection of GRB 231115A (a probable Magnetar Giant Flare from M82)
  74. GRB 231115A: AGILE/MCAL upper limits
  75. GRB 231115A: Insight-HXMT/HE detection
  76. GRB 231115A: GBM/Fermi Observations of a probable Giant Flare of Magnetar
  77. GRB 231115A : MITSuME Akeno and Okayama optical upper limits
  78. GRB 231115A: Gaoyazi/GOT follow-up and archival observations
  79. GRB 231115A / AT2023xvj: Updated GIT analysis
  80. GRB 231115A: archival Chandra X-ray observations
  81. GRB 231115A: Upper limits from a neutrino search with IceCube
  82. GRB 231115A: Kinder observations with Lulin observatory
  83. GRB231115A: GRANDMA Observations
  84. GRB 231115A: GOTO pre-burst limits of AT2023xvj
  85. GRB 231115A: Non-detection in low-latency of gravitational waves with LIGO/Virgo/KAGRA
  86. GRB 231115A: pre-burst ZTF upper limits for GRB optical counterpart candidate
  87. GRB 231106A: TESS identification of candidate optical counterpart
  88. GRB 231115A: MASTER optical observations
  89. GRB 231115A (short): Glowbug gamma-ray detection
  90. GRB 231115A: Fermi Observations of a probable Magnetar Giant Flare from M82
  91. GRB 231115A: archival HST observations
  92. GRB 231115A: GROWTH-India discovery of a potential optical counterpart
  93. GRB 231115A: Swift ToO observations
  94. Fermi GRB 231115A: Global MASTER-Net observations report
  95. GRB 231115A: significance of INTEGRAL localization alignment with M82
  96. GRB 231115A position consistent with M 82 galaxy
  97. LIGO/Virgo/KAGRA S231113bw: Updated Sky localization, EM Bright Classification, and Source Classification
  98. GRB 231111A: Swift-BAT refined analysis
  99. LIGO/Virgo/KAGRA S231113bw: Zwicky Transient Facility observations
  100. LIGO/Virgo/KAGRA S231114n: Updated Sky localization

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