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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"

27241 results found.

  1. Fermi GRB 241104A: Global MASTER-Net observations report
  2. GRB 241104A: Fermi GBM Final Real-time Localization
  3. EP241101a: EP-FXT observations update
  4. EP241103a: GIT optical upper limit
  5. EP241021a: OHP/T193 further optical observations
  6. LIGO/Virgo/KAGRA S241104a: Retraction of GW compact binary merger candidate
  7. Fermi trigger No 752365806: Global MASTER-Net observations report
  8. EP241103a: GOTO optical upper limit
  9. EP241101a: Possible detection of an optical counterpart with FTW
  10. EP241101a: Optical upper limits with Kinder observations
  11. EP241103a: Gemini optical limits
  12. EP241103a: EP observation update
  13. LIGO/Virgo/KAGRA S241102br: MASTER observations and OT detection
  14. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  15. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  16. EP241103a: GSP optical upper limit
  17. EP241103A: LCO optical observations
  18. EP241103a: Global MASTER-Net observations report
  19. EP241103a: an X-ray transient detected by Einstein Probe
  20. GRB 241030A: Rapid release of TESS data.
  21. EP241101a: Global MASTER-Net observations report
  22. EP241101a: BOOTES-7 optical upper limit
  23. GRB241030A: OHP/T193 optical observations
  24. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  25. EP241101a: EP-WXT detection of a fast X-ray transient
  26. Swift GRB 241101A: Global MASTER-Net observations report
  27. GRB 241101A: FRAM-ORM optical limit
  28. GRB 241101A: Swift-BAT refined analysis
  29. EP241021a: Liverpool Telescope optical follow-up observations
  30. GRB 241030B: Swift-XRT refined Analysis
  31. GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
  32. EP241030a: EP/FXT observation of GRB 241030A X-ray Afterglow
  33. GRB 241101A: Swift detection of a burst
  34. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  35. EP241021a: OHP/T193 optical observations
  36. GRB 241030A: Palomar 1-m telescope COSMOS optical observations
  37. GRB 241030B: Montarrenti Observatory optical upper limit
  38. GRB 241030A / EP241030a: FTW Optical and NIR observations of the optical counterpart
  39. EP241026b: Liverpool Telescope optical follow-up
  40. Fermi trigger No 752083996: Global MASTER-Net observations report
  41. GRB 241030A: Fermi GBM Observation
  42. GRB 241030B : GIT optical upper limits
  43. GRB 241030B: LCOGT Optical Upper Limits
  44. GRB 241030B: Swift-BAT refined analysis
  45. GRB 241030A: Swift-BAT refined analysis
  46. GRB 241029A: COLIBRI Detection of the Optical Counterpart
  47. GRB 241030B: Swift/UVOT Detection
  48. EP EP241030a: Global MASTER-Net observations report
  49. GRB 241029A: LCO optical detection
  50. Fermi trigger No 752006065: Global MASTER-Net observations report
  51. GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82
  52. Swift GRB241030.77: Global MASTER-Net observations report
  53. GRB 241030B: SVOM/GRM observation
  54. GRB 241030B : MITSuME Akeno optical upper limits
  55. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  56. GRB 241030B: SVOM/VT optical afterglow observations
  57. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  58. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  59. GRB241030B: Fermi GBM Observation
  60. GRB 241029A: SVOM/VT optical afterglow observations
  61. GRB 241030B: optical observations from the INAF Asiago Observatory
  62. GRB241030B: GRANDMA/TAROT Upper Limit
  63. GRB 241030A: Swift-XRT refined Analysis
  64. GRB 241030B: SAO RAS optical observations
  65. GRB 241030B: AKO Optical Afterglow Detection
  66. GRB 241030B: Nanshan/HMT optical afterglow detection
  67. GRB 241030B: SVOM/ECLAIRs detection of a burst
  68. GRB 241030B: Swift detection of a burst
  69. GRB 241030B: Fermi GBM Final Real-time Localization
  70. GRB 241030A: Fermi-LAT detection
  71. Fermi GRB 241030A: Global MASTER-Net observations report
  72. GRB 241030A: AKO Optical Afterglow Detection
  73. Swift GRB 241030A: Global MASTER-Net observations report
  74. GRB 241030A: Swift/UVOT Detection
  75. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  76. GRB 241030A: SVOM/GRM observation
  77. GRB 241026A: Swift-BAT refined analysis
  78. GRB 241030A: SVOM/C-GFT optical observations
  79. EP241026b: EP-FXT follow-up observation
  80. GRB 241030A: Multiband optical detection with Mephisto
  81. GRB 241030A: SVOM/VT optical afterglow observations
  82. GRB 241030A : MITSuME Akeno optical afterglow detection
  83. GRB 241029A: GROWTH-India Telescope optical follow up
  84. GRB 241030A: TRT optical observations
  85. GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
  86. GRB 241030A: COLIBRÍ Detection of the Bright Optical Counterpart
  87. GRB 241030A: Swift detection of a burst with a bright optical counterpart
  88. GRB 241030A: Fermi GBM Final Real-time Localization
  89. GRB 241029A: GTC/OSIRIS+ spectroscopic redshift z=1.072
  90. EP241021a: ATCA radio observations
  91. GRB 241026A: Swift/UVOT Upper Limits
  92. GRB 241029A: Fermi GBM Observation
  93. GRB 241029A: AKO Optical Afterglow Detection
  94. GRB 241029A: GOTO optical afterglow detection
  95. GRB 241029A: MASTER early optical counterpart detection
  96. GRB 241029A: Xinglong-2.16m optical afterglow confirmation
  97. EP 241026b: LBT possible optical counterpart (brightening source)
  98. GRB 241029A: TRT optical afterglow candidate detection
  99. GRB 241029A: SVOM/GRM observation
  100. GRB 241029A : Detection and localization of a bright long GRB by SVOM/ECLAIRs

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