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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').

16007 results found.

  1. GRB 240403A: Glowbug gamma-ray detection
  2. LXT 240402A/GRB 240402B: Glowbug gamma-ray detection
  3. X-ray transient LXT 240402A: WFST optical upper limits​
  4. Konus-Wind detection of LXT 240402A/GRB 240402B
  5. GRB/FXT 240402B: Kinder optical counterpart candidate
  6. GRB/FXT 240402B: VLT/FORS2 optical afterglow candidate
  7. GRB 240404A: Fermi GBM Final Real-time Localization
  8. X-ray transient LXT 240402A: LEIA detection
  9. X-ray transient EP240331a: Kinder optical upper limits
  10. Transient EP240315a: J-band observations of AT2024eju with WIRC
  11. X-ray transient EP20240331a: MeerLICHT optical upper limits
  12. IceCube-240327B: Upper limits from a search for additional neutrino events in IceCube
  13. IceCube-240327A: Upper limits from a search for additional neutrino events in IceCube
  14. GRB 240329A: Glowbug gamma-ray detection
  15. GRB 240329A: AstroSat CZTI detection
  16. X-ray transient EP240315a: continued ATCA monitoring
  17. GRB 240328C: Glowbug gamma-ray detection
  18. X-ray transient EP 240315a: Second epoch Chandra observations
  19. X-ray transient EP240315a: Ondrejov D50 optical limit
  20. Transient EPW20240219aa: REM optical/NIR further observations
  21. GRB 240320A: Glowbug gamma-ray detection
  22. X-ray transient EP240315a: ATCA detection of radio counterpart
  23. IPN triangulation of GRB 240315C (consistent with a fast X-ray transient EP240315a)
  24. X-ray transient EP240315a: MeerKAT radio detection
  25. GRB 240318A: Glowbug gamma-ray detection
  26. GRB 240317C: Glowbug gamma-ray detection
  27. GRB 240318B: Glowbug gamma-ray detection
  28. X-ray transient EP240315a: PRIME near infrared detection
  29. X-ray transient EP240315a: 3.6 m TNG NIR detection
  30. X-ray transient EP240315a/AT2024eju: TShAO (Zeiss-1000) observatory optical upper limit
  31. Fermi GRB 240318A: Global MASTER-Net observations report
  32. GRB 240317A: AstroSat CZTI detection
  33. GRB 240315B: AstroSat CZTI detection
  34. X-ray transient EP240315a: Kitab observatory optical upper limitns
  35. X-ray transient EP240315a: Montarrenti Observatory optical upper limit
  36. X-ray transient EP240315a: orphan FXT?
  37. X-ray transient EP240315a: Kinder follow-up observations for AT 2024eju with Lulin observatory
  38. X-ray transient EP240315a: VLT/X-shooter spectroscopic redshift of z = 4.859
  39. X-ray transient EP240315a: Nanshan/HMT optical upper limit
  40. Einstein Probe detected of a fast X-ray transient EP240315a
  41. GRID detection of GRB 240306A
  42. GRB240204A: VIRT optical upper limit
  43. GRB 240312A: Glowbug gamma-ray detection
  44. GRB 240310B: Glowbug gamma-ray detection
  45. IceCube-240307A: Upper limits from a search for additional neutrino events in IceCube
  46. GRID detection of GRB 240229A (Updated Report)
  47. GRB 231215A: further radio observations with the VLA
  48. GRB 240229A: Glowbug gamma-ray detection
  49. GRB 240227A (short): Glowbug gamma-ray detection
  50. GRB 240306A: AstroSat CZTI detection
  51. GRB 231028C: Glowbug gamma-ray confirmation of a prior burst
  52. GRB 240218A: Chandra Detection and Jet Break Confirmation
  53. Swift Trigger 1218701: Yes, we triggered on Swift J151857.0-572147 again
  54. GRB240218A: ATCA observation of the radio counterpart
  55. Transient EPW20240219aa: Optical observations with LDT
  56. GRB 240225B: Swift-XRT afterglow detection
  57. Swift detection of Swift J151857.0-572147
  58. GRB 240215A: Swift-XRT afterglow detection
  59. GRB 240303A: Swift detection of a burst
  60. GRB 240225B: Glowbug gamma-ray detection
  61. IceCube-240229A: Upper limits from a search for additional neutrino events in IceCube
  62. GRB 240225C: Glowbug gamma-ray detection
  63. GRB 240225A (short): Glowbug gamma-ray detection
  64. GRB 240229A: DDOTI Upper Limits on the Afterglow
  65. GRB 240218A: NOEMA upper limit
  66. GRB 240225B: further SAO RAS optical observations
  67. GRB 240225B: VLT/X-shooter redshift
  68. GRB 240225B : MITSuME Akeno optical afterglow candidate detection
  69. GRB 240225B: 3.6m DOT observation
  70. GRB 240225B: WINTER near-IR observations and upper limits
  71. GRB 240225B: SAO RAS optical observations
  72. GRB 240225B: Mondy afterglow observations
  73. GRB 240225B: Liverpool Telescope optical afterglow observations
  74. GRB 240218A: CMO SAI NIR upper limit
  75. GRB 240225B: Nanshan/HMT optical afterglow detection
  76. GRB 240225B: Swift-XRT observations
  77. Transient EPW20240219aa: Kp-band imaging observations with NIRES
  78. Transient EPW20240219aa: REM optical/NIR upper limits
  79. GRB 240225B: AstroSat CZTI detection
  80. Transient EPW20240219aa: Xinglong-2.16m optical upper limit
  81. Transient EPW20240219aa: GECKO: LOAO Optical Upper Limits
  82. Transient EPW20240219aa: 7DT Optical Upper Limits
  83. VLA X-band observation of EPW20240219aa
  84. Transient EPW20240219aa: Mondy optical observations
  85. Insight-HXMT/HE Sub-Threshold Detection of Transient EPW20240219aa
  86. Swift BAT Sub-Threshold Detection of EPW20240219aa
  87. Transient EPW20240219aa: Liverpool Telescope non-detection and limiting magnitude
  88. GRB 240222A: Fermi GBM Observation
  89. GRB 240222A: Swift/UVOT Upper Limits
  90. GRB 240222A: REM optical and NIR early-time observations
  91. GRB 240222A: Swift detection of a burst
  92. GRB 240218A: MeerLICHT upper limits
  93. GRB 240216A: Glowbug gamma-ray detection
  94. GRB 240218A: LBT H-band detection
  95. GRB 240218A: VLT/X-shooter redshift of z = 6.782
  96. GRB 240218A: Enhanced Swift-XRT position
  97. GRB 240218A: REM detection of a NIR afterglow candidate
  98. Gamma-ray flaring activity from the blazar 1ES 1959+650 observed by the Fermi-LAT
  99. GRB 240218A : r-band upper limit from Observatoire de Haute-Provence
  100. GRB240218A: VLT/X-shooter upper limits

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