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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"

32703 results found.

  1. IceCube-241224A: No transient candidates from the Zwicky Transient Facility
  2. Swift GRB 241229B: Global MASTER-Net observations report
  3. GRB 241229A: GOTO optical upper limits
  4. GRB 241228B: VLT/X-shooter redshift of z = 2.674
  5. GRB 241228A: NOT optical upper limits
  6. GRB 241228B: LCO optical observation
  7. GRB 241228A: Swift-BAT refined analysis
  8. GRB 241228B: Swift/BAT-GUANO localization skymap of a burst
  9. Fermi GRB 241228B: Global MASTER-Net observations report
  10. GRB 241228A: Fermi GBM Observation
  11. GRB241228B: GROWTH-India Telescope optical observations
  12. Swift GRB 241228A: Global MASTER-Net observations report
  13. GRB 241228B: LCOGT photometry of the likely optical counterpart GOTO24jmz
  14. GRB 241228B: GOTO24jmz optical follow-up observations
  15. GRB 241226A: Swift/BAT-GUANO localization skymap of a burst
  16. GRB 241228A: GROWTH-India telescope optical upper limit
  17. GRB 241228B: Swift ToO observations
  18. GRB 241228B: TRT optical counterpart confirmation
  19. GRB 241228A: Swift/UVOT Upper Limits
  20. GRB 241228B: GOTO possible optical counterpart candidate
  21. IceCube-241224A: Upper limits from a search for additional neutrino events in IceCube
  22. GRB 241223A: GRBAlpha detection
  23. GRB 241212A: VZLUSAT-2 detection
  24. GRB 241217A/EP241217b: continued SOAR observations
  25. Fermi GRB 241226A: Global MASTER-Net observations report
  26. EP241223a: Mondy AZT-33IK optical observations
  27. GRB 241029A: LCO optical observation
  28. GRB 241223A: Swift-XRT observations
  29. LIGO/Virgo/KAGRA S241225v: Identification of a GW compact binary merger candidate
  30. GRB 241029A: AbAO AS-32 optical observations
  31. LIGO/Virgo/KAGRA S241225c: Identification of a GW compact binary merger candidate
  32. EP241223a
  33. EP241223a: Global MASTER-Net observations report
  34. EP241113a: Non-detection in Radio Follow-up Observations with eMERLIN
  35. GRB241113A: 7DT Optical upper limits
  36. Fermi GRB 241223A: Global MASTER-Net observations report
  37. GRB 241223A: GOTO optical observations summary
  38. GRB 241105A: JWST photometric observations of the host galaxy
  39. GRB 241223A: Swift ToO observations
  40. EP241217a: e-MERLIN radio observations
  41. GRB 241217A / EP241217b: Non-detection in ATCA Radio Follow-up Observations
  42. GRB 241209B: host galaxy detection and GTC/OSIRIS+ spectroscopy
  43. Fermi GRB 241221A: Global MASTER-Net observations report
  44. GRB 241217A/EP241217b: SOAR afterglow detection
  45. EP241217a: Liverpool Telescope optical upper limit
  46. EP241021a: VLA radio detection
  47. GRB 241218A: Mondy AZT-33IK optical upper limit
  48. EP241217a : Leavitt Observatory optical upper limit
  49. GRB 241217A/EP241217b: tentative VLT spectroscopic redshift z=1.879
  50. EP241217a: 1.6m Mephisto multi-band optical observations
  51. GRB 241217a/EP241217B: 1.6m Mephisto optical upper limits
  52. GRB 241218A: Swift/UVOT Upper Limits
  53. EP241217a: optical upper limit with the Liverpool Telescope
  54. GRB 241209B: EP-FXT afterglow detection
  55. Konus-Wind detection of GRB 241204A (short/hard)
  56. GRB 241218A: NOT optical upper limits
  57. GRB 241218A: Swift-BAT refined analysis
  58. GRB 241217A / EP241217B: GRANDMA/T1MPicduMidi optical upperlimits
  59. EP 241217a: NIR detection with P200/WIRC
  60. EP 241217a: Possible J-band detection with WINTER
  61. GRB 241217A/EP241217B: Fermi-GBM Sub-Threshold Detection
  62. EP241217a: refined EP-WXT analysis and EP-FXT follow-up observations
  63. GRB 241217A / EP241217b: Nanshan/HMT optical upper limit
  64. GRB 241217A: refined SVOM/MXT data analysis. Long lasting X-ray emission.
  65. GRB 241217A / EP241217b: NOT optical upper limits
  66. GRB 241218A: REM optical upper limit
  67. GRB 241217A/EP241217b: REM optical/NIR upper limits
  68. EP241217a: REM optical/NIR upper limits
  69. GRB 241218a: Liverpool Telescope optical follow-up
  70. GRB 241217a: Liverpool Telescope optical follow-up
  71. EP241217a: Liverpool Telescope optical follow-up
  72. EP241217a: NOT optical observations
  73. EP241217a: GROWTH-India Telescope optical observations
  74. GRB 241218A: NUTTelA-TAO / BSTI Optical Limits
  75. EP241119a: 7DT Optical upper limits
  76. EP241217b: Global MASTER-Net observations report
  77. GRB 241209A: ATCA radio follow-up observations
  78. EP241217a: Xinglong optical follow-up observations
  79. EP241217b/GRB 241217A: EP detection of the prompt X-ray emssion
  80. GRB 241218A: LCOGT Optical Upper Limit
  81. EP241217a: Global MASTER-Net observations report
  82. GRB 241217A: GMG Optical Upper Limit
  83. GRB 241217A : SVOM/VT optical afterglow detection
  84. GRB 241217A: LCO optical upper limit
  85. GRB 241217A: GRANDMA/TAROT optical upperlimits
  86. EP241217a: Swift-XRT Detection
  87. EP241217A: Non-detection from Fermi-GBM Observations
  88. EP241217a: Gemini-North spectroscopic redshift z = 4.59
  89. EP241217a: Kinder optical follow-up observations
  90. GRB 241214A: GRBAlpha detection
  91. GRB 241213A (EP241213a): GRBAlpha detection
  92. GRB 241209D: GRBAlpha detection
  93. EP241217A: LCO optical observations
  94. EP241217a: Gemini-North detection of the likely optical counterpart
  95. EP241107a: VLA Radio Observation
  96. GRB 241213A: Swift-BAT refined analysis
  97. GRB 241214A: Swift/BAT-GUANO localization skymap of a burst
  98. Konus-Wind detection of GRB 241213A (EP 241213a)
  99. GRB 241215A: Mondy AZT-33IK optical observations
  100. GRB 241215A: Nanshan/HMT optical upper limit

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