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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').

10636 results found.

  1. GRB 241229A: EP-FXT X-ray afterglow confirmation
  2. EP241217A: J band upper limit by SYSU 80cm telescope
  3. GRB 241229B: CrAO ZTSh possible optical counterpart of SVOM/VT confirmation
  4. Konus-Wind detection of GRB 241228A
  5. EP240702a: 7DT Optical upper limits
  6. GRB 240606B: 7DT Optical upper limits
  7. GRB 241228B: Swift-XRT afterglow detection
  8. GRB 241228B: Swift/BAT-GUANO localization skymap of a burst
  9. Fermi GRB 241228B: Global MASTER-Net observations report
  10. GRB 241226A: Swift/BAT-GUANO localization skymap of a burst
  11. GRB 241228A: Swift-XRT refined Analysis
  12. GRB 241228A: Swift detection of a burst
  13. GRB 241217A/EP241217b: continued SOAR observations
  14. Fermi GRB 241226A: Global MASTER-Net observations report
  15. Fermi trigger No 756678579: Global MASTER-Net observations report
  16. IceCube Alert 241224.30: Global MASTER-Net observations report
  17. EP241223a: Global MASTER-Net observations report
  18. EP241113a: Non-detection in Radio Follow-up Observations with eMERLIN
  19. GRB241113A: 7DT Optical upper limits
  20. Fermi Gamma-ray Burst Monitor trigger 756678579 / 241223854 is not a GRB
  21. Fermi GRB 241223A: Global MASTER-Net observations report
  22. GRB 241223A: GOTO optical observations summary
  23. EP241217a: e-MERLIN radio observations
  24. GRB 241217A / EP241217b: Non-detection in ATCA Radio Follow-up Observations
  25. Fermi trigger No 756447119: Global MASTER-Net observations report
  26. GRB 241217A/EP241217b: SOAR afterglow detection
  27. EP241217a: Liverpool Telescope optical upper limit
  28. GRB 241218A: Mondy AZT-33IK optical upper limit
  29. Konus-Wind detection of GRB 241204A (short/hard)
  30. EP 241217a: NIR detection with P200/WIRC
  31. GRB 241217A / EP241217b: NOT optical upper limits
  32. GRB 241218A: Swift-XRT refined Analysis
  33. EP241119a: 7DT Optical upper limits
  34. EP241217b/GRB 241217A: EP detection of the prompt X-ray emssion
  35. EP241217a: Global MASTER-Net observations report
  36. GRB 241218A: Swift detection of a burst
  37. EP241217a: Swift-XRT Detection
  38. EP241217a: EP detection of an X-ray transient
  39. GRB 241214A: Swift/BAT-GUANO localization skymap of a burst
  40. Konus-Wind detection of GRB 241213A (EP 241213a)
  41. The EP-WXT trigger 01709128948 is likely a flaring star
  42. GRB 241215A: A long GRB detected by INTEGRAL
  43. GRB 241213A: Swift-XRT refined Analysis
  44. EP 241208A : Detection of a long soft transient by SVOM/ECLAIRs
  45. GRB 241213B: MAXI/GSC detection
  46. GRB 241213A: Swift detection of a burst
  47. GRB 241209B: Mondy AZT-33IK and AbAO AS-32 optical observations
  48. Konus-Wind detection of GRB 241209B
  49. GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
  50. Konus-Wind detection of GRB 241209D
  51. GRB 241209C: Fermi GBM Observation
  52. GRB 241209A: Swift-XRT refined Analysis
  53. GRB 241209A: EP-FXT follow-up observations
  54. EP241208a: Global MASTER-Net observations report
  55. EP241208a: EP-FXT follow-up observations
  56. Fermi trigger No 755485387: Global MASTER-Net observations report
  57. GRB 241207B: Fermi GBM Observation
  58. GRB 241209D: Swift-XRT refined Analysis
  59. GRB 241209D: COLIBRÍ detection of the afterglow
  60. Fermi GRB 241209D: Global MASTER-Net observations report
  61. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  62. Swift GRB 241209D: Global MASTER-Net observations report
  63. Fermi GRB 241209A: Global MASTER-Net observations report
  64. GRB 241209B: SVOM/ECLAIRs and GRM detection of a long burst
  65. EP241208a: EP detection of a fast X-ray transient
  66. GRB 241207B: Swift/BAT-GUANO localization skymap of a short burst
  67. Fermi Gamma-ray Burst Monitor trigger 755277791/241207641 is not a GRB
  68. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  69. GRB 241207C: MAXI/GSC detection
  70. GRB 241207B: Fermi GBM Final Real-time Localization
  71. Fermi GRB 241207A: Global MASTER-Net observations report
  72. EP241206a: Global MASTER-Net observations report
  73. EP241206a: EP detection of a fast X-ray transient
  74. GRB 241206A: Fermi GBM observation
  75. GRB 241206A: Swift/BAT-GUANO localization skymap of a burst
  76. EP241113a: Keck/LRIS spectroscopic observation and tentative redshift
  77. Fermi GRB 241206A: Global MASTER-Net observations report
  78. LIGO/Virgo/KAGRA S241125n: gamma-ray upper limits from joint observations by the LST-1 and MAGIC telescopes
  79. GRB 241204A: Fermi-LAT detection
  80. IceCube-241127A: No transient candidates from the Zwicky Transient Facility
  81. Konus-Wind detection of GRB 241130A
  82. EP241201a: BOOTES-5 optical upper limit
  83. EP241202b: EP detection of a fast X-ray transient
  84. GRB 241129A: Swift/BAT-GUANO localization skymap of a burst
  85. EP241201a: Global MASTER-Net observations report
  86. GRB 241127B: detection of a long GRB by SVOM/ECLAIRs
  87. Fermi trigger No 754701230: Global MASTER-Net observations report
  88. Konus-Wind detection of GRB 241114B
  89. LIGO/Virgo/KAGRA S241130n: Identification of a GW compact binary merger candidate
  90. Fermi-LAT gamma-ray observations of IceCube-241127A
  91. LIGO/Virgo/KAGRA S241129aa: Identification of a GW compact binary merger candidate
  92. GRB 241128A: Swift-XRT refined Analysis
  93. LIGO/Virgo S241127aj: GRANDMA/FRAM-CTA-N Observations
  94. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  95. GRB 241127A: Swift-XRT refined Analysis
  96. GRB 241127A: Swift detection of a burst with an optical counterpart
  97. Swift GRB241127.91: Global MASTER-Net observations report
  98. Swift GRB241127.91: Global MASTER-Net OT detection
  99. LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
  100. LIGO/Virgo/KAGRA S241127aj: NED Galaxies in the Localization Volume

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