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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"

3335 results found.

  1. GRB 241229A: SAO RAS optical observations
  2. GRB 241229A: Swift-XRT observations
  3. Konus-Wind detection of GRB 241228A
  4. GRB 241229A: EP-FXT afterglow candidates
  5. EP240702a: 7DT Optical upper limits
  6. EP241223a
  7. EP241223a: Global MASTER-Net observations report
  8. EP241223a: EP-WXT detection of a fast X-ray transient
  9. EP241113a: Non-detection in Radio Follow-up Observations with eMERLIN
  10. GRB 241217A / EP241217b: Non-detection in ATCA Radio Follow-up Observations
  11. The EP-WXT trigger 01709129287 is likely a flaring star
  12. EP241021a: VLA radio detection
  13. EP241217a : Leavitt Observatory optical upper limit
  14. EP241217a: 1.6m Mephisto multi-band optical observations
  15. GRB 241209B: EP-FXT afterglow detection
  16. Konus-Wind detection of GRB 241204A (short/hard)
  17. EP 241217a: NIR detection with P200/WIRC
  18. EP 241217a: Possible J-band detection with WINTER
  19. GRB 241217A/EP241217B: Fermi-GBM Sub-Threshold Detection
  20. EP241217a: refined EP-WXT analysis and EP-FXT follow-up observations
  21. GRB 241217A: refined SVOM/MXT data analysis. Long lasting X-ray emission.
  22. GRB 241217A/EP241217b: REM optical/NIR upper limits
  23. EP241217a: REM optical/NIR upper limits
  24. EP241217a: NOT optical observations
  25. EP241217a: GROWTH-India Telescope optical observations
  26. EP241119a: 7DT Optical upper limits
  27. EP241217b: Global MASTER-Net observations report
  28. EP241217a: Xinglong optical follow-up observations
  29. EP241217b/GRB 241217A: EP detection of the prompt X-ray emssion
  30. EP241217a: Global MASTER-Net observations report
  31. EP241217a: Swift-XRT Detection
  32. EP241217A: Non-detection from Fermi-GBM Observations
  33. EP241217a: Kinder optical follow-up observations
  34. GRB 241213A (EP241213a): GRBAlpha detection
  35. EP241217A: LCO optical observations
  36. EP241217a: Gemini-North detection of the likely optical counterpart
  37. EP241217a: EP detection of an X-ray transient
  38. The EP-WXT trigger 01709129023 is likely a flaring star
  39. Konus-Wind detection of GRB 241213A (EP 241213a)
  40. The EP-WXT trigger 01709128948 is likely a flaring star
  41. The EP-WXT trigger 01709128921 is likely a flaring star
  42. EP trigger ID 01709128824 is not a real source
  43. EP241208a: NOT optical upper limits
  44. EP 241208A : Detection of a long soft transient by SVOM/ECLAIRs
  45. EP241213a/GRB241213a: Likely joint detection and INTEGRAL/SPI-ACS counterpart
  46. EP241213a: EP detection of An X-ray Transient
  47. Konus-Wind detection of GRB 241209B
  48. Konus-Wind detection of GRB 241209D
  49. EP241208a: Optical upper limit with Kinder observations
  50. GRB 241209A: EP-FXT follow-up observations
  51. EP241208a: Global MASTER-Net observations report
  52. EP241208a: EP-FXT follow-up observations
  53. EP241206a: 1.5m OSN optical limit
  54. EP241208a: EP detection of a fast X-ray transient
  55. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  56. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  57. EP241206a: BOOTES Global Network optical limits
  58. EP241206a: Global MASTER-Net observations report
  59. EP241206a: EP detection of a fast X-ray transient
  60. EP241201a: 1.6m Mephisto Optical Upper Limits
  61. EP241202b: Upper limits from Fermi-GBM Observations
  62. EP241202b: Kinder optical counterpart candidate
  63. EP241201a: EP-FXT follow-up observations
  64. Konus-Wind detection of GRB 241130A
  65. EP241202b: Global MASTER-Net observations report
  66. EP241201a: BOOTES-5 optical upper limit
  67. EP241202b: EP detection of a fast X-ray transient
  68. EP241201a: NOT optical observations
  69. EP241201a: Kinder optical counterpart candidate
  70. EP241201a: Global MASTER-Net observations report
  71. EP241201a: EP detection of a fast X-ray transient
  72. The EP-WXT trigger 01709126243 is not a real source
  73. EP241126a: 1.6m Mephisto Optical Upper Limits
  74. Konus-Wind detection of GRB 241114B
  75. LIGO/Virgo/KAGRA S241125n: GRANDMA Optical Upper Limits
  76. EP241126a: NOT optical observations
  77. EP241126a: SVOM/VT observations
  78. The EP-WXT trigger 01709125191 is not a real source
  79. EP241126a: WFST Observations
  80. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations (duplicate submission of 38345)
  81. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations (duplicate submission of 38345).
  82. LIGO/Virgo/KAGRA S241125n: EP-FXT follow-up observations
  83. EP241126a: Optical Upper limits with Kinder observations
  84. EP trigger ID 01709122294: 1.6m Mephisto multi-band optical observations
  85. EP241126a: EP-FXT follow-up observation update
  86. EP241126a: GSP detects optical counterpart
  87. EP241126a: TRT optical counterpart detection
  88. EP241126a: EP detection of a fast X-ray transient
  89. GRB 241113B: EP-FXT afterglow detection
  90. Konus-Wind detection of GRB 241115D / EP 241115a
  91. LIGO/Virgo/KAGRA S241125n: Upper limits from Konus-Wind observations
  92. EP241125a: Optical upper limit with Kinder observations
  93. EP241125a: EP detection of an X-ray transient
  94. LIGO/Virgo/KAGRA S241125n: No counterpart candidates in INTEGRAL SPI-ACS prompt observation, comparisong with Swift/BAT counterpart
  95. GRB 241113B: SVOM/VT optical afterglow observations
  96. Konus-Wind detection of GRB 241117A
  97. GRB 241025A: VIRT Optical Upper Limit
  98. Konus-Wind detection of GRB 241120A
  99. EP trigger ID 01709065118: Keck/LRIS spectroscopic observations
  100. EP-WXT trigger 01709018832: Lick/Kast spectroscopy with the 3 m Shane telescope

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