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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"

21981 results found.

  1. Swift GRB 240809A: Global MASTER-Net observations report
  2. GRB 240809A: JinShan optical observations
  3. GRB 240809A: Skynet & Photon Ranch Optical Afterglow Observations
  4. EP-WXT trigger 01709018832: SVOM/C-GFT observations of the star flare
  5. EP240807a: STEP/T80S optical limits
  6. IceCube Alert 240808.27: Global MASTER-Net observations report
  7. EP EP240807a: Global MASTER-Net observations report
  8. EP EP240806a: Global MASTER-Net observations report
  9. GRB 240805A: ATCA Radio Upper Limits
  10. Fermi trigger No 744761058: Global MASTER-Net observations report
  11. EP-WXT trigger 01709018832: KAIT optical observations of the star flare
  12. EP240806A: Liverpool Telescope optical follow-up observations
  13. EP240807a: EP-WXT detection of a fast X-ray transient
  14. EP240806a: Gemini North-GMOS spectroscopic redshift of z = 2.818
  15. GRB 240805B: GIT optical upper limit
  16. EP240806a: KAIT optical observations
  17. Fermi trigger No 744629911: Global MASTER-Net observations report
  18. EP240804a (GRB 240804B): NOT optical observations
  19. EP240806a: LCOGT optical counterpart detection
  20. GRB 240805B Bassano Bresciano Observatory upper limit
  21. GRB 240805B: JinShan optical afterglow detection
  22. GRB 240805B: AbAO, CrAO, and Terskol optical upper limits
  23. EP 240806A: LCO optical observations
  24. EP240806a: GSP optical counterpart detection
  25. EP240806a: EP-WXT detection of a fast X-ray transient
  26. GRB 240805B: Optical detection with 1.6m Mephisto
  27. GRB 240805B: NUTTelA-TAO / BSTI Optical Limits
  28. Fermi trigger No 744544656: Global MASTER-Net observations report
  29. GRB 240805B: Swift/UVOT Upper Limits
  30. GRB 240805A: Swift/UVOT Upper Limits
  31. Swift GRB 240805B: Global MASTER-Net observations report
  32. GRB 240805B: JinShan optical upper limits
  33. Fermi GRB 240805A: Global MASTER-Net observations report
  34. Swift GRB 240805A: Global MASTER-Net observations report
  35. EP240804a: GSP detects optical candidate counterpart
  36. EP240801a: Continued optical observations at ZTSh (CraO)
  37. EP240804a: VLT/X-shooter spectroscopic redshift
  38. EP240804a: LCOGT optical counterpart detection
  39. EP240804a: NOT optical counterpart detection
  40. EP240804a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  41. GRB 240805A: Swift detection of a burst
  42. Fermi GRB 240804A: Global MASTER-Net observations report
  43. EP240802a: Montarrenti Observatory optical upper limit
  44. Fermi trigger No 744459130: Global MASTER-Net observations report
  45. EP240801a: Osservatorio Astronomico Nastro Verde upper limit
  46. EP240802A: Bassano Bresciano Observatory upper limit
  47. GRB 240802A: SVOM/GRM observation
  48. EP240802a: Time coincidence with GRB 240802A and optical upper limits with Kinder observations
  49. Fermi trigger No 744278264: Global MASTER-Net observations report
  50. EP240802a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  51. EP240801a: further SAO RAS optical observations
  52. EP240801a: optical observations at CrAO and AbAO
  53. EP240801a: GRANDMA and Kilonova-Catcher optical observations
  54. EP240801a: Leavitt Observatory optical observations
  55. EP240801a: GTC spectroscopy and absorption redshift
  56. EP240801a: SAO RAS optical observations
  57. EP240801a: JinShan optical observations
  58. EP240801a: NOT optical observations
  59. EP240801a: follow-up observation with LCOGT
  60. EP240801a: GSP follow-up observations of the candidate counterpart
  61. Fermi trigger No 744204856: Global MASTER-Net observations report
  62. EP240801a: Kinder follow-up observations of the candidate counterpart
  63. EP240708a: Kinder follow-up observations of the candidate counterpart (duplicate submission of GCN 37002)
  64. EP240801a: KAIT optical counterpart observations
  65. EP240801a: TRT optical counterpart detection
  66. EP240801a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  67. Fermi GRB 240801A: Global MASTER-Net observations report
  68. Fermi trigger No 744128417: Global MASTER-Net observations report
  69. Fermi trigger No 744083370: Global MASTER-Net observations report
  70. GRB 240730A: Osservatorio Astronomico Nastro Verde upper limit
  71. Fermi GRB 240730B: Global MASTER-Net observations report
  72. Swift GRB 240730A: Global MASTER-Net observations report
  73. GRB 240715A: Swift-XRT afterglow detection
  74. GRB 240730A: Swift/UVOT Upper Limits
  75. Fermi trigger No 743953682: Global MASTER-Net observations report
  76. LIGO/Virgo/KAGRA S240615dg: GRAWITA wide-field optical observations
  77. GRB 240727A: observations of optical counterpart.
  78. GRB 240727B: Swift-XRT observations
  79. Fermi GRB 240727A: Global MASTER-Net observations report
  80. GRB 240727A: Swift/UVOT detection
  81. Fermi trigger No 743868421: Global MASTER-Net observations report
  82. GRB 240727A: Osservatorio Astronomico Nastro Verde upper limit
  83. GRB 240727A: JinShan optical upper limits
  84. GRB 240727A Bassano Bresciano Observatory upper limit
  85. Fermi GRB 240726A: Global MASTER-Net observations report
  86. Swift GRB240727.16: Global MASTER-Net observations report
  87. GRB 240727B: Swift ToO observations
  88. GRB 240727B: Swift/BAT-GUANO arcminute localization of a long burst
  89. GRB240727A: Skynet Optical Afterglow Observations
  90. GRB 240727A: TRT optical afterglow detection
  91. GRB 240727A: KAIT Optical Afterglow Candidate
  92. Fermi-LAT gamma-ray observations of IceCube-240725A
  93. IceCube Alert 240725.22: Global MASTER-Net observations report
  94. Swift GRB240725.11: Global MASTER-Net observations report
  95. IceCube-240721A: Two candidates from the Zwicky Transient Facility
  96. Fermi trigger No 743418632: Global MASTER-Net observations report
  97. Fermi trigger No 743315411: Global MASTER-Net observations report
  98. LIGO/Virgo/KAGRA S240716b: Upper limits from Swift/BAT-GUANO
  99. LIGO/Virgo/KAGRA S240703ad: Upper limits from Swift/BAT-GUANO
  100. Fermi trigger No 743345551: Global MASTER-Net observations report

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