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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"

19210 results found.

  1. EP260822a: Global MASTER-Net observations report
  2. EP Alert 260820.31: Global MASTER-Net observations report
  3. IceCube-260825A: No transient candidates from the Zwicky Transient Facility
  4. GRB 260807A: EP-FXT follow-up observations
  5. GRB 260822A: SVOM/ECLAIRs refined analysis
  6. GRB 260809A: SVOM/ECLAIRs refined analysis
  7. IceCube Alert 260825A: Global MASTER-Net observations report
  8. IceCube-Cascade 260824A: Upper limits from a search for additional neutrino events in IceCube
  9. GRB 260825A: Fermi GBM Final Real-time Localization
  10. GRB 260822A: PRIME near-infrared upper limits from multiple epochs
  11. GRB 260822A: EP/FXT follow-up observations
  12. GRB 260822A: the candidate optical afterglow is an unrelated type-Ia SN
  13. GRB 260818A: further EP-FXT observations and X-ray afterglow confirmation
  14. EP260822a: EP-FXT non-detection and upper limit
  15. GRB 260822A: GOTO optical counterpart detection
  16. GRB 260822A: SVOM/VT optical detection of COLIBRÍ candidate
  17. GRB 260822A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  18. EP260822a: Einstein Probe detection of a fast X-ray transient
  19. GRB 260822A: LCO optical upper limits
  20. The EP-WXT trigger 01709287395 is likely a flaring star
  21. GRB260822B: Fermi GBM Final Localization
  22. GRB 260822A: GROWTH-India Telescope Upper Limits
  23. GRB 260822A: GOTO optical upper limit
  24. GRB 260822A: SVOM detection of a short burst
  25. Fermi-LAT Gamma-ray Observations of IceCube-260821A
  26. Fermi-LAT Gamma-ray Observations of IceCube-260807A
  27. IceCube-260821A: Upper limits from a search for additional neutrino events in IceCube
  28. GRB 260818B: VLA radio observations
  29. GRB 260818B: SVOM/C-GFT optical upper limit
  30. EP260731a: SVOM/ECLAIRs detection through offline targeted search
  31. IceCube Alert 260821A: Global MASTER-Net observations report
  32. The EP-WXT trigger 01709286204 is likely a flaring star
  33. GRB 260820A: Insight-HXMT/HE detection
  34. GRB 260818B: SVOM/GRM observation
  35. EP detected a brightening of LMXB 1ES 1735-26.9
  36. GRB260820A: Fermi GBM Final Real-Time Localization
  37. GRB 260818B: Insight-HXMT detection
  38. GRB 260818B: EP-FXT follow-up observation
  39. GRB 260818A: J-band observations with WINTER
  40. GRB 260818B: SVOM/ECLAIRs refined analysis
  41. GRB 260818A: SVOM/ECLAIRs refined analysis
  42. GRB 260818B: NOT optical upper limits
  43. GRB 260810A: SVOM/GRM observation
  44. GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  45. GRB260818A: EP-FXT follow-up observation
  46. GRB 260818B: LCO optical upper limits
  47. GRB 260818B: SVOM detection of a short burst
  48. SVOM trigger sb26081806 is not a GRB
  49. EP260806a: SAO RAS multicolor optical observations
  50. GRB 260818A: LCO optical upper limits
  51. EP260812a: AbAO optical upper limit
  52. GRB 260818A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  53. GRB 260810A: Insight-HXMT/HE detection
  54. GRB 260818A: SVOM possible detection of a long and faint GRB
  55. EP260806a: SVOM/ECLAIRs detection through targeted search
  56. EP260806a: NUTTELA-TAO optical observations
  57. The EP-WXT trigger 01709281429 is likely a flaring star
  58. EP260812a: AZT-22 optical upper limit
  59. EP260812b: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.034
  60. EP260806a: WFST optical observations
  61. The EP-WXT trigger 01709280562 is likely a flaring star
  62. EP260812b: Optical upper limit with Kinder
  63. The EP-WXT trigger 01709279838 is likely a flaring star
  64. GRB 260805D: SVOM/GRM detection of a possible magnetar burst
  65. GRB 260808B: Liverpool Telescope further optical observations
  66. GRB 260808B: GTC/OSIRIS+ spectroscopic redshift z = 1.295
  67. GRB 260813A: BALROG localization (Fermi Trigger 808341387 / GRB 260813803)
  68. GRB 260813A: Fermi GBM Final Real-time Localization
  69. EP260812a: NOT and Liverpool Telescope upper limits:
  70. EP260812b: Liverpool Telescope observations
  71. EP260812b: GOTO detection of the optical counterpart
  72. EP260812a: refined analysis of the EP-WXT and autonomous EP-FXT observation
  73. EP260812a: SVOM/C-GFT optical upper limit
  74. EP260812b: COLIBRÍ optical observations
  75. EP260812b: SVOM/VT optical observation
  76. GRB 260808A: SVOM/GRM observation
  77. EP260812b: Einstein Probe detection of an X-ray transient
  78. EP trigger #01709278129 (EP260812b?): NOT optical counterpart
  79. Fermi GBM Sub-Threshold Detection of GRB 260809A
  80. GRB 260810A: Glowbug gamma-ray detection
  81. GRB 260808B: SVOM/COLIBRÍ (FM-GFT) confirmation of the optical rebrightening
  82. GRB 260810A: AstroSat CZTI detection of a long burst
  83. EP260812a: Einstein Probe detection of an X-ray transient
  84. GRB 260809A: SAO RAS optical observations
  85. GRB 260808B: SAO RAS optical observations
  86. GRB 260808B: SVOM/VT optical re-brightening at day 3
  87. GRB 260317A: SVOM/ECLAIRs detection through offline targeted search and its possible association to magnetar 1E 1841-04.5
  88. GRB 260806A: CALET Gamma-Ray Burst Monitor detection
  89. GRB 260808A: GECAM-B observation
  90. EP260806a: MAO/AZT-22 optical observations
  91. IceCube-260807A: Upper limits from a search for additional neutrino events in IceCube
  92. GRB260808B: MAO/AZT-22 optical observations
  93. GRB 260809A: J-band upper limit with WINTER
  94. EP260809a: VLT/X-shooter spectroscopic redshift z = 3.07
  95. GRB 260806A: Glowbug gamma-ray detection
  96. GRB 260808A: CALET Gamma-Ray Burst Monitor detection
  97. GRB 260805C: CALET Gamma-Ray Burst Monitor detection
  98. GRB 260804A: CALET Gamma-Ray Burst Monitor detection
  99. GRB260809A/EPF_J234751.2+210212: EP-FXT follow-up observation
  100. The EP-WXT trigger 01709278015 is likely a flaring star

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