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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"

43125 results found.

  1. GRB 241217A / EP241217b: NOT optical upper limits
  2. GRB 241218A: REM optical upper limit
  3. GRB 241217A/EP241217b: REM optical/NIR upper limits
  4. EP241217a: REM optical/NIR upper limits
  5. GRB 241218a: Liverpool Telescope optical follow-up
  6. GRB 241217a: Liverpool Telescope optical follow-up
  7. EP241217a: Liverpool Telescope optical follow-up
  8. GRB 241218A: Swift-XRT refined Analysis
  9. EP241217a: NOT optical observations
  10. EP241217a: GROWTH-India Telescope optical observations
  11. GRB 241218A: NUTTelA-TAO / BSTI Optical Limits
  12. EP241119a: 7DT Optical upper limits
  13. EP241217b: Global MASTER-Net observations report
  14. GRB 241209A: ATCA radio follow-up observations
  15. EP241217a: Xinglong optical follow-up observations
  16. EP241217b/GRB 241217A: EP detection of the prompt X-ray emssion
  17. GRB 241218A: LCOGT Optical Upper Limit
  18. GRB 241218A: Enhanced Swift-XRT position
  19. EP241217a: Global MASTER-Net observations report
  20. GRB 241217A: GMG Optical Upper Limit
  21. GRB 241218A: Swift detection of a burst
  22. GRB 241217A : SVOM/VT optical afterglow detection
  23. GRB 241217A: Swift-XRT afterglow detection
  24. GRB 241217A: LCO optical upper limit
  25. GRB 241217A: GRANDMA/TAROT optical upperlimits
  26. EP241217a: Swift-XRT Detection
  27. EP241217A: Non-detection from Fermi-GBM Observations
  28. GRB 241217A : SVOM/ECLAIRs,GRM,MXT detection of a long burst with a bright X-ray afterglow candidate
  29. EP241217a: Gemini-North spectroscopic redshift z = 4.59
  30. EP241217a: Kinder optical follow-up observations
  31. GRB 241214A: GRBAlpha detection
  32. GRB 241213A (EP241213a): GRBAlpha detection
  33. GRB 241209D: GRBAlpha detection
  34. EP241217A: LCO optical observations
  35. EP241217a: Gemini-North detection of the likely optical counterpart
  36. EP241217a: EP detection of an X-ray transient
  37. The EP-WXT trigger 01709129023 is likely a flaring star
  38. EP241107a: VLA Radio Observation
  39. GRB 241213A: Swift-BAT refined analysis
  40. GRB 241214A: Swift/BAT-GUANO localization skymap of a burst
  41. Konus-Wind detection of GRB 241213A (EP 241213a)
  42. GRB 241215A: Mondy AZT-33IK optical observations
  43. GRB 241212A: Swift-XRT observations
  44. GRB 241214A: SVOM/GRM observation
  45. The EP-WXT trigger 01709128948 is likely a flaring star
  46. GRB 241215A: Nanshan/HMT optical upper limit
  47. GRB 241215A: Montarrenti Observatory optical upper limit
  48. GRB 241215A: GROWTH-India telescope optical upper limit
  49. GRB 241215A: A long GRB detected by INTEGRAL
  50. Integral GRB241215.58: Global MASTER-Net observations report
  51. The EP-WXT trigger 01709128921 is likely a flaring star
  52. GRB 241213B: Swift-XRT observations
  53. GRB 241209D: CALET Gamma-Ray Burst Monitor detection
  54. GRB 241209B: SVOM/VT optical continuous fading
  55. EP trigger ID 01709128824 is not a real source
  56. GRB 241213A: SVOM/VT optical candidate
  57. GRB 241213B: Tiled Swift observations
  58. GRB 241213A: Swift/UVOT Upper Limits
  59. GRB 241213B: CALET Gamma-Ray Burst Monitor detection
  60. GRB 241213A: Swift-XRT refined Analysis
  61. GRB 241212A: Fermi GBM detection
  62. EP241208a: NOT optical upper limits
  63. GRB 241212A: Swift ToO observations
  64. GRB 241213A: LCOGT Optical Upper Limits
  65. EP 241208A : Detection of a long soft transient by SVOM/ECLAIRs
  66. EP241213a/GRB241213a: Likely joint detection and INTEGRAL/SPI-ACS counterpart
  67. GRB 241213B: MAXI/GSC detection
  68. EP241213a: EP detection of An X-ray Transient
  69. GRB 241213A: REM optical/NIR upper limits
  70. GRB 241213A: Enhanced Swift-XRT position
  71. GRB241212A: OHP/T193 optical observations
  72. GRB 241213A: SAO RAS optical upper limit
  73. LIGO/Virgo/KAGRA S241210fu: Updated Sky localization
  74. Swift GRB 241213A: Global MASTER-Net observations report
  75. GRB 241213A: Swift detection of a burst
  76. GRB 241212A : SVOM/C-GFT optical upper limit at early phase
  77. GRB 241212A : SVOM/VT bright optical afterglow
  78. GRB 241212A: AstroSat CZTI detection
  79. GRB 241209B: GRANDMA/TRT upper limit
  80. GRB 241207A: TSHAO Zeiss-1000 optical observations
  81. GRB 241212A: SVOM detection of a bright long burst
  82. GRB 241212A: Fermi GBM Final Real-time Localization
  83. GRB 241209B: Mondy AZT-33IK and AbAO AS-32 optical observations
  84. GRB 241209A: Chandra X-ray Detection
  85. Konus-Wind detection of GRB 241209B
  86. GRB 241207A: EIRSAT-1 GMOD Detection
  87. GRB 241209A: Redshift of the likely host galaxy z = 0.784 from OSIRIS+/GTC
  88. GRB 241209B: GRBAlpha detection
  89. GRB 241206C: GRBAlpha detection
  90. LIGO/Virgo/KAGRA S241210cw: Updated Sky localization
  91. LIGO/Virgo/KAGRA S241210d: Updated Sky localization and EM Bright Classification
  92. GRB 241211A: Fermi GBM Final Real-time Localization
  93. GRB 241129A: Fermi GBM Observation
  94. GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
  95. GRB 241209D: REM optical/NIR upper limits
  96. Konus-Wind detection of GRB 241209D
  97. GRB 241209B: Swift-XRT afterglow detection
  98. GRB 241209C: Fermi GBM Observation
  99. LIGO/Virgo/KAGRA S241210fu: Identification of a GW compact binary merger candidate
  100. EP241208a: Optical upper limit with Kinder observations

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