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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"

23599 results found.

  1. GRB 241226A: Swift/BAT-GUANO localization skymap of a burst
  2. GRB 241228A: GROWTH-India telescope optical upper limit
  3. GRB 241228B: TRT optical counterpart confirmation
  4. GRB 241228A: Swift-XRT refined Analysis
  5. GRB 241228A: Swift/UVOT Upper Limits
  6. GRB 241228B: GOTO possible optical counterpart candidate
  7. GRB 241228A: Enhanced Swift-XRT position
  8. GRB 241228A: Swift detection of a burst
  9. LIGO/Virgo/KAGRA S241225c: Two counterpart neutrino candidates from IceCube neutrino searches
  10. EP241223a: Mondy AZT-33IK optical observations
  11. GRB 241029A: LCO optical observation
  12. GRB 241223A: Swift-XRT observations
  13. LIGO/Virgo/KAGRA S241225v: Identification of a GW compact binary merger candidate
  14. GRB 241029A: AbAO AS-32 optical observations
  15. LIGO/Virgo/KAGRA S241225c: Identification of a GW compact binary merger candidate
  16. EP241223a
  17. EP241223a: EP-WXT detection of a fast X-ray transient
  18. GRB241113A: 7DT Optical upper limits
  19. GRB 241223A: GOTO optical observations summary
  20. GRB 241105A: JWST photometric observations of the host galaxy
  21. EP241217a: e-MERLIN radio observations
  22. GRB 241209B: host galaxy detection and GTC/OSIRIS+ spectroscopy
  23. EP241217a: Liverpool Telescope optical upper limit
  24. EP241021a: VLA radio detection
  25. GRB 241218A: Mondy AZT-33IK optical upper limit
  26. EP241217a : Leavitt Observatory optical upper limit
  27. EP241217a: 1.6m Mephisto multi-band optical observations
  28. GRB 241217a/EP241217B: 1.6m Mephisto optical upper limits
  29. GRB 241218A: Swift/UVOT Upper Limits
  30. EP241217a: optical upper limit with the Liverpool Telescope
  31. GRB 241218A: NOT optical upper limits
  32. GRB 241217A / EP241217B: GRANDMA/T1MPicduMidi optical upperlimits
  33. EP 241217a: NIR detection with P200/WIRC
  34. EP 241217a: Possible J-band detection with WINTER
  35. EP241217a: refined EP-WXT analysis and EP-FXT follow-up observations
  36. GRB 241217A / EP241217b: Nanshan/HMT optical upper limit
  37. GRB 241217A / EP241217b: NOT optical upper limits
  38. GRB 241218A: REM optical upper limit
  39. GRB 241217A/EP241217b: REM optical/NIR upper limits
  40. EP241217a: REM optical/NIR upper limits
  41. GRB 241218a: Liverpool Telescope optical follow-up
  42. GRB 241217a: Liverpool Telescope optical follow-up
  43. EP241217a: Liverpool Telescope optical follow-up
  44. EP241217a: NOT optical observations
  45. EP241217a: GROWTH-India Telescope optical observations
  46. GRB 241218A: NUTTelA-TAO / BSTI Optical Limits
  47. EP241119a: 7DT Optical upper limits
  48. EP241217a: Xinglong optical follow-up observations
  49. EP241217b/GRB 241217A: EP detection of the prompt X-ray emssion
  50. GRB 241218A: LCOGT Optical Upper Limit
  51. GRB 241218A: Enhanced Swift-XRT position
  52. GRB 241217A: GMG Optical Upper Limit
  53. GRB 241218A: Swift detection of a burst
  54. GRB 241217A : SVOM/VT optical afterglow detection
  55. GRB 241217A: Swift-XRT afterglow detection
  56. GRB 241217A: LCO optical upper limit
  57. GRB 241217A: GRANDMA/TAROT optical upperlimits
  58. EP241217a: Swift-XRT Detection
  59. GRB 241217A : SVOM/ECLAIRs,GRM,MXT detection of a long burst with a bright X-ray afterglow candidate
  60. EP241217a: Kinder optical follow-up observations
  61. EP241217A: LCO optical observations
  62. EP241217a: Gemini-North detection of the likely optical counterpart
  63. EP241217a: EP detection of an X-ray transient
  64. EP241107a: VLA Radio Observation
  65. GRB 241214A: Swift/BAT-GUANO localization skymap of a burst
  66. GRB 241215A: Mondy AZT-33IK optical observations
  67. GRB 241212A: Swift-XRT observations
  68. GRB 241215A: Nanshan/HMT optical upper limit
  69. GRB 241215A: Montarrenti Observatory optical upper limit
  70. GRB 241215A: GROWTH-India telescope optical upper limit
  71. GRB 241209B: SVOM/VT optical continuous fading
  72. GRB 241213A: SVOM/VT optical candidate
  73. GRB 241213A: Swift/UVOT Upper Limits
  74. EP241208a: NOT optical upper limits
  75. GRB 241213A: LCOGT Optical Upper Limits
  76. EP241213a: EP detection of An X-ray Transient
  77. GRB 241213A: REM optical/NIR upper limits
  78. GRB 241213A: Enhanced Swift-XRT position
  79. GRB241212A: OHP/T193 optical observations
  80. GRB 241213A: SAO RAS optical upper limit
  81. GRB 241213A: Swift detection of a burst
  82. GRB 241212A : SVOM/C-GFT optical upper limit at early phase
  83. GRB 241209B: GRANDMA/TRT upper limit
  84. GRB 241212A: SVOM detection of a bright long burst
  85. Konus-Wind detection of GRB 241209B
  86. LIGO/Virgo/KAGRA S241210d: Updated Sky localization and EM Bright Classification
  87. GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
  88. GRB 241209D: REM optical/NIR upper limits
  89. GRB 241209B: Swift-XRT afterglow detection
  90. LIGO/Virgo/KAGRA S241210fu: Identification of a GW compact binary merger candidate
  91. EP241208a: Optical upper limit with Kinder observations
  92. LIGO/Virgo/KAGRA S241210cw: Identification of a GW compact binary merger candidate
  93. LIGO/Virgo/KAGRA S241210d: Identification of a GW compact binary merger candidate
  94. GRB 241209D: Fermi GBM Observation
  95. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  96. GRB 241209D: COLIBRÍ detection of the afterglow
  97. GRB 241209A: COLIBRÍ Optical Upper Limit
  98. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  99. GRB 241209A: GRANDMA/TAROT upper limit
  100. GRB 241209A: REM optical/NIR observations

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