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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

6402 results found.

  1. GRB 241229A: SAO RAS optical observations
  2. GRB 241229A: Swift-XRT observations
  3. GRB 241229A: EP-FXT afterglow candidates
  4. EP240702a: 7DT Optical upper limits
  5. GRB 241228B: Fermi GBM Observation
  6. GRB 241228B: Swift-XRT afterglow detection
  7. GRB 241229B: Fermi GBM Observation
  8. GRB 241229B: Swift-XRT refined Analysis
  9. GRB 241228A: NOT optical upper limits
  10. GRB 241228A: Fermi GBM Observation
  11. GRB 241228B: TRT optical counterpart confirmation
  12. GRB 241228A: Swift-XRT refined Analysis
  13. GRB 241223A: Swift-XRT observations
  14. GRB 241223A: Fermi GBM Detection
  15. GRB241113A: 7DT Optical upper limits
  16. GRB 241218A: NOT optical upper limits
  17. EP 241217a: NIR detection with P200/WIRC
  18. GRB 241217A: refined SVOM/MXT data analysis. Long lasting X-ray emission.
  19. GRB 241218A: Swift-XRT refined Analysis
  20. EP241119a: 7DT Optical upper limits
  21. GRB 241217A : SVOM/VT optical afterglow detection
  22. GRB 241217A: Swift-XRT afterglow detection
  23. EP241217a: Swift-XRT Detection
  24. EP241217a: Kinder optical follow-up observations
  25. GRB 241212A: Swift-XRT observations
  26. GRB 241213B: Swift-XRT observations
  27. GRB 241213A: Swift-XRT refined Analysis
  28. GRB 241212A: Fermi GBM detection
  29. EP241213a: EP detection of An X-ray Transient
  30. GRB 241213A: SAO RAS optical upper limit
  31. GRB 241209A: Chandra X-ray Detection
  32. GRB 241129A: Fermi GBM Observation
  33. Konus-Wind detection of GRB 241209D
  34. GRB 241209B: Swift-XRT afterglow detection
  35. GRB 241209C: Fermi GBM Observation
  36. GRB 241209A: Swift-XRT refined Analysis
  37. EP241208a: Optical upper limit with Kinder observations
  38. EP241208a: EP-FXT follow-up observations
  39. GRB 241207B: Fermi GBM Observation
  40. GRB 241209D: Swift-XRT refined Analysis
  41. GRB 241209D: Fermi GBM Observation
  42. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  43. GRB 241209A: Fermi GBM Observation
  44. EP241206a: 1.5m OSN optical limit
  45. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  46. GRB 241206A: Fermi GBM observation
  47. EP241201a: 1.6m Mephisto Optical Upper Limits
  48. LIGO/Virgo/KAGRA S241125n: gamma-ray upper limits from joint observations by the LST-1 and MAGIC telescopes
  49. GRB 241204A: Fermi GBM Observation
  50. Fermi GRB 241204A: Global MASTER-Net observations report
  51. GRB 241204A: Fermi-LAT detection
  52. EP241202b: Kinder optical counterpart candidate
  53. EP241201a: EP-FXT follow-up observations
  54. GRB 241130A: Fermi GBM Detection
  55. EP241201a: Kinder optical counterpart candidate
  56. Swift-XRT observations of IceCube -241127A
  57. Fermi-LAT gamma-ray observations of IceCube-241127A
  58. GRB 241128A: Swift-XRT refined Analysis
  59. GRB 241128A: Swift-XRT afterglow detection
  60. GRB 241127A: Swift-XRT refined Analysis
  61. LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
  62. LIGO/Virgo/KAGRA S241125n: Swift-UVOT Upper Limits
  63. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations
  64. EP241126a: Optical Upper limits with Kinder observations
  65. EP241126a: TRT optical counterpart detection
  66. LIGO/Virgo S241125n: Swift XRT observations, 5 X-ray sources
  67. Konus-Wind detection of GRB 241115D / EP 241115a
  68. LIGO/Virgo/KAGRA S241125n: Upper limits from Konus-Wind observations
  69. LIGO/Virgo/KAGRA S241125n: Kinder optical upper limit in the BAT error region
  70. LIGO/Virgo/KAGRA S241125n: No counterpart candidates in INTEGRAL SPI-ACS prompt observation, comparisong with Swift/BAT counterpart
  71. EP241119a: Optical upper limits with Kinder observations
  72. EP241119a: GIT optical upper limits
  73. GRB 241120A: Fermi GBM Observation
  74. GRB 241112B: Mephisto further optical observations
  75. GRB 241115B: Fermi GBM Observation
  76. GRB 241117A: Fermi GBM Detection
  77. GRB 241115C: Fermi GBM Observation
  78. GRB 241115A: Swift-XRT afterglow detection
  79. EP241115a/GRB 241115D: Optical upper limits with Kinder observations
  80. GRB 241113B: Mephisto upper limits
  81. GRB 241115A: Fermi GBM Observation
  82. GRB 241030A: LCO optical observation
  83. GRB 241113B: Swift-XRT observations
  84. GRB 241113A: 1.6m Mephisto and 50cm array optical upper limits
  85. Fermi-LAT gamma-ray observations of IceCube-241113A
  86. GRB 241113A: Swift-XRT refined Analysis
  87. GRB 241112B: Swift-XRT afterglow detection
  88. GRB 241108A: Swift-XRT observations
  89. EP241107a: Kinder optical follow-up observations
  90. EP241107a: GIT optical observations
  91. GRB 241105A: Swift/UVOT Detection
  92. GRB 241105A: Fermi GBM Observation of a Short Burst with Extended Emission
  93. Konus-Wind detection of GRB 241105A (short with extended emission)
  94. GRB 241105A: Swift-XRT afterglow detection
  95. GRB 241104A: Swift-XRT observations
  96. GRB 241104A: Fermi GBM Observation
  97. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  98. EP241104a: EP detection of GRB 241104A X-ray emission
  99. EP241101a: EP-FXT observations update
  100. EP241103a: GIT optical upper limit

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