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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"

21093 results found.

  1. GRB 231117A: GTC Near-Infrared Observations
  2. GRB 231117A: AMI-LA radio observations
  3. GRB 231117A: LDT Confirmation of Optical Fading
  4. GRB 231117A: Wendelstein Confirmation of Fading of the Optical Afterglow
  5. 231118A: Swift-UVOT Detection
  6. GRB231117A: Swift-UVOT detection
  7. LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
  8. GRB 231118A: MeerLICHT afterglow detection
  9. GRB 231117A: OHP/T120 optical observations
  10. Fermi trigger No 722039659: Global MASTER-Net observations report
  11. GRB 231117A: Pan-STARRS1 follow-up confirms rapid fading
  12. GRB 231117A: 10 GHz VLA detection
  13. GRB 231118A: LCOGT Optical Observations
  14. GRB 231118A: MASTER OT observation
  15. GRB 231118A: Continued Skynet Observations
  16. Swift GRB231118.72: Global MASTER-Net observations report
  17. GRB 231117A: Kinder observations with Lulin observatory for AT 2023yba without fading in r band
  18. GRB 231117A: Lowell Discovery Telescope Observations
  19. GRB 231117A: ePESSTO+ host galaxy redshift confirmation
  20. GRB 231117A: ATCA detection of a radio counterpart
  21. GRB 231117A: Keck spectroscopy of afterglow candidate
  22. GRB 231115A: Wendelstein Optical/Infrared Observations
  23. GRB 231115A: JinShan optical upper limits
  24. GRB 231117A: LT observations consistent with fading
  25. GRB 231117A: Keck observations indicate presence of optical afterglow in z~0.3-0.5 galaxy
  26. GRB 231117A: REM optical and NIR early-time observations
  27. GRB 231117A: afterglow candidate detection from Kinder observations with Lulin observatory
  28. Swift GRB 231117A: Global MASTER-Net observations report
  29. GRB 231117A: ATLAS non-detection of an optical counterpart
  30. GRB 231115A : OHP/T120 optical upper limit
  31. GRB 231115A: optical observations from INAF observatories
  32. GRB 231111A: Swift/UVOT Detection
  33. MAGIC observation of GRB 231115A, a possible magnetar giant flare
  34. GRB 231115A: NuSTAR Follow-Up Observations
  35. GRB 231115A: Swift-XRT and Swift-UVOT observations
  36. Fermi GRB 231116A: Global MASTER-Net observations report
  37. GRB 231115A: GBM/Fermi Observations of a probable Giant Flare of Magnetar
  38. GRB 231115A: Gaoyazi/GOT follow-up and archival observations
  39. GRB 231115A: archival Chandra X-ray observations
  40. GRB 231115A: Kinder observations with Lulin observatory
  41. GRB231115A: GRANDMA Observations
  42. GRB 231115A: GOTO pre-burst limits of AT2023xvj
  43. GRB 231115A: pre-burst ZTF upper limits for GRB optical counterpart candidate
  44. GRB 231106A: TESS identification of candidate optical counterpart
  45. GRB 231115A: MASTER optical observations
  46. GRB 231115A: Fermi Observations of a probable Magnetar Giant Flare from M82
  47. GRB 231115A: archival HST observations
  48. Integral GRB231115.65: Global MASTER-Net observations report
  49. GRB 231115A: GROWTH-India discovery of a potential optical counterpart
  50. GRB 231115A: Swift ToO observations
  51. Fermi GRB 231115A: Global MASTER-Net observations report
  52. GRB 231115A position consistent with M 82 galaxy
  53. LIGO/Virgo/KAGRA S231113bw: Zwicky Transient Facility observations
  54. Fermi GRB 231114A: Global MASTER-Net observations report
  55. LIGO/Virgo/KAGRA S231113bw: GROWTH-India coverage and upper limits
  56. LIGO/Virgo/KAGRA S231113bw: Upper limits from Fermi-GBM Observations
  57. LIGO/Virgo/KAGRA S231113cd: Coverage and upper limits from MAXI/GSC observations
  58. LIGO/Virgo/KAGRA S231113bw: Coverage and upper limits from MAXI/GSC observations
  59. GRB231111A: MDM 2.4m Hiltner Telescope Observation
  60. GRB 231111A: Xinglong-2.16m optical observations
  61. GRB 231110A: Swift-UVOT Upper Limits
  62. GRB 231111A: Afterglow redshift from OSIRIS+/GTC
  63. GRB 231111A: TNG tentative redshift
  64. GRB 231111A NUTTelA-TAO / BSTI Early Measurements
  65. GRB 231111A: Leavitt Observatory optical observations
  66. GRB231111A: Optical follow-up observations with Mephisto
  67. GRB 231111A: Osservatorio Astronomico "Nastro Verde" optical observations with detection of an optical counterpart
  68. GRB 231110A: Terskol Zeiss-2000 optical upper limit
  69. GRB 231111A: Mondy optical observations
  70. GRB 231110A: SAO RAS optical observations
  71. GRB 231110A: Swift-XRT afterglow detection
  72. GRB231111A: YAHPT Observations
  73. GRB 231111A: MASTER OT earlier detection
  74. GRB 231111A: Nanshan/HMT optical observations
  75. Swift GRB231111.60: Global MASTER-Net observations report
  76. GRB231110A: WFST Observation and upper limits
  77. Swift GRB231110.89: Global MASTER-Net observations report
  78. IceCube-231103A: No candidates from the Zwicky Transient Facility
  79. Fermi trigger No 721204446: Global MASTER-Net observations report
  80. Fermi GRB 231108A: Global MASTER-Net observations report
  81. Fermi trigger No 721006392: Global MASTER-Net observations report
  82. Fermi GRB 231106A: Global MASTER-Net observations report
  83. GRB 231104A: Wendelstein Optical/Infrared Observations
  84. Fermi-LAT gamma-ray observations of IceCube-231103A
  85. GRB 231104A: NOT upper limit
  86. Fermi GRB 231103A: Global MASTER-Net observations report
  87. GRB 231104A: Swift/UVOT Upper Limits
  88. Swift GRB231104.07: Global MASTER-Net observations report
  89. IceCube Alert 231103.39: Global MASTER-Net observations report
  90. Fermi-LAT gamma-ray observations of IceCube-231027A
  91. LIGO/Virgo/KAGRA S231102i: Global MASTER-Net observations report
  92. GRB 231024A: GRANDMA observations of AT2023vuc/GOTO23baj candidate
  93. New Swift-BAT/GUANO and IceCube Notices Available via GCN Kafka
  94. Fermi trigger No 720498201: Global MASTER-Net observations report
  95. Fermi trigger No 720415645: Global MASTER-Net observations report
  96. Fermi GRB 231030B: Global MASTER-Net observations report
  97. Fermi GRB 231030A: Global MASTER-Net observations report
  98. LIGO/Virgo/KAGRA S231029ai: Global MASTER-Net observations report
  99. LIGO/Virgo/KAGRA S231029k: Global MASTER-Net observations report
  100. Fermi trigger No 720224759: Global MASTER-Net observations report

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