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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"

21095 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: AMI-LA radio observations
  5. GRB 231117A: LDT Confirmation of Optical Fading
  6. GRB 231117A: Wendelstein Confirmation of Fading of the Optical Afterglow
  7. 231118A: Swift-UVOT Detection
  8. GRB231117A: Swift-UVOT detection
  9. LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
  10. GRB 231118A: MeerLICHT afterglow detection
  11. GRB 231117A: OHP/T120 optical observations
  12. Fermi trigger No 722039659: Global MASTER-Net observations report
  13. GRB 231117A: Pan-STARRS1 follow-up confirms rapid fading
  14. GRB 231117A: 10 GHz VLA detection
  15. GRB 231118A: LCOGT Optical Observations
  16. GRB 231118A: MASTER OT observation
  17. GRB 231118A: Continued Skynet Observations
  18. Swift GRB231118.72: Global MASTER-Net observations report
  19. GRB 231117A: Kinder observations with Lulin observatory for AT 2023yba without fading in r band
  20. GRB 231117A: Lowell Discovery Telescope Observations
  21. GRB 231117A: ePESSTO+ host galaxy redshift confirmation
  22. GRB 231117A: ATCA detection of a radio counterpart
  23. GRB 231117A: Keck spectroscopy of afterglow candidate
  24. GRB 231115A: Wendelstein Optical/Infrared Observations
  25. GRB 231115A: JinShan optical upper limits
  26. GRB 231117A: LT observations consistent with fading
  27. GRB 231117A: Keck observations indicate presence of optical afterglow in z~0.3-0.5 galaxy
  28. GRB 231117A: REM optical and NIR early-time observations
  29. GRB 231117A: afterglow candidate detection from Kinder observations with Lulin observatory
  30. Swift GRB 231117A: Global MASTER-Net observations report
  31. GRB 231117A: ATLAS non-detection of an optical counterpart
  32. GRB 231115A : OHP/T120 optical upper limit
  33. GRB 231115A: optical observations from INAF observatories
  34. GRB 231111A: Swift/UVOT Detection
  35. MAGIC observation of GRB 231115A, a possible magnetar giant flare
  36. GRB 231115A: NuSTAR Follow-Up Observations
  37. GRB 231115A: Swift-XRT and Swift-UVOT observations
  38. Fermi GRB 231116A: Global MASTER-Net observations report
  39. GRB 231115A: GBM/Fermi Observations of a probable Giant Flare of Magnetar
  40. GRB 231115A: Gaoyazi/GOT follow-up and archival observations
  41. GRB 231115A: archival Chandra X-ray observations
  42. GRB 231115A: Kinder observations with Lulin observatory
  43. GRB231115A: GRANDMA Observations
  44. GRB 231115A: GOTO pre-burst limits of AT2023xvj
  45. GRB 231115A: pre-burst ZTF upper limits for GRB optical counterpart candidate
  46. GRB 231106A: TESS identification of candidate optical counterpart
  47. GRB 231115A: MASTER optical observations
  48. GRB 231115A: Fermi Observations of a probable Magnetar Giant Flare from M82
  49. GRB 231115A: archival HST observations
  50. Integral GRB231115.65: Global MASTER-Net observations report
  51. GRB 231115A: GROWTH-India discovery of a potential optical counterpart
  52. GRB 231115A: Swift ToO observations
  53. Fermi GRB 231115A: Global MASTER-Net observations report
  54. GRB 231115A position consistent with M 82 galaxy
  55. LIGO/Virgo/KAGRA S231113bw: Zwicky Transient Facility observations
  56. Fermi GRB 231114A: Global MASTER-Net observations report
  57. LIGO/Virgo/KAGRA S231113bw: GROWTH-India coverage and upper limits
  58. LIGO/Virgo/KAGRA S231113bw: Upper limits from Fermi-GBM Observations
  59. LIGO/Virgo/KAGRA S231113cd: Coverage and upper limits from MAXI/GSC observations
  60. LIGO/Virgo/KAGRA S231113bw: Coverage and upper limits from MAXI/GSC observations
  61. GRB231111A: MDM 2.4m Hiltner Telescope Observation
  62. GRB 231111A: Xinglong-2.16m optical observations
  63. GRB 231110A: Swift-UVOT Upper Limits
  64. GRB 231111A: Afterglow redshift from OSIRIS+/GTC
  65. GRB 231111A: TNG tentative redshift
  66. GRB 231111A NUTTelA-TAO / BSTI Early Measurements
  67. GRB 231111A: Leavitt Observatory optical observations
  68. GRB231111A: Optical follow-up observations with Mephisto
  69. GRB 231111A: Osservatorio Astronomico "Nastro Verde" optical observations with detection of an optical counterpart
  70. GRB 231110A: Terskol Zeiss-2000 optical upper limit
  71. GRB 231111A: Mondy optical observations
  72. GRB 231110A: SAO RAS optical observations
  73. GRB 231110A: Swift-XRT afterglow detection
  74. GRB231111A: YAHPT Observations
  75. GRB 231111A: MASTER OT earlier detection
  76. GRB 231111A: Nanshan/HMT optical observations
  77. Swift GRB231111.60: Global MASTER-Net observations report
  78. GRB231110A: WFST Observation and upper limits
  79. Swift GRB231110.89: Global MASTER-Net observations report
  80. IceCube-231103A: No candidates from the Zwicky Transient Facility
  81. Fermi trigger No 721204446: Global MASTER-Net observations report
  82. Fermi GRB 231108A: Global MASTER-Net observations report
  83. Fermi trigger No 721006392: Global MASTER-Net observations report
  84. Fermi GRB 231106A: Global MASTER-Net observations report
  85. GRB 231104A: Wendelstein Optical/Infrared Observations
  86. Fermi-LAT gamma-ray observations of IceCube-231103A
  87. GRB 231104A: NOT upper limit
  88. Fermi GRB 231103A: Global MASTER-Net observations report
  89. GRB 231104A: Swift/UVOT Upper Limits
  90. Swift GRB231104.07: Global MASTER-Net observations report
  91. IceCube Alert 231103.39: Global MASTER-Net observations report
  92. Fermi-LAT gamma-ray observations of IceCube-231027A
  93. LIGO/Virgo/KAGRA S231102i: Global MASTER-Net observations report
  94. GRB 231024A: GRANDMA observations of AT2023vuc/GOTO23baj candidate
  95. New Swift-BAT/GUANO and IceCube Notices Available via GCN Kafka
  96. Fermi trigger No 720498201: Global MASTER-Net observations report
  97. Fermi trigger No 720415645: Global MASTER-Net observations report
  98. Fermi GRB 231030B: Global MASTER-Net observations report
  99. Fermi GRB 231030A: Global MASTER-Net observations report
  100. LIGO/Virgo/KAGRA S231029ai: Global MASTER-Net observations report

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