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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"

6805 results found.

  1. GRB 200612A: Fermi GBM detection
  2. GRB 200613A: Fermi-LAT detection
  3. GRB 200613A: Fermi GBM observation
  4. GRB 200612A: Swift-XRT refined Analysis
  5. GRB 200530A: Fermi GBM detection
  6. GRB 200530A: Fermi-LAT detection
  7. Fermi-LAT Gamma-ray Observations of IceCube-200530A
  8. IceCube-200530A: No significant detection in HAWC
  9. IceCube-200530A: Candidate Counterparts from the Zwicky Transient Facility
  10. IceCube-200530A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  11. GRB 200529A: Swift-XRT refined Analysis
  12. GRB 200529A: Fermi GBM Detection
  13. GRB 200528A: Swift-XRT refined Analysis
  14. GRB 200529A: NOT optical afterglow
  15. GRB 200528A: Fermi GBM Observation
  16. Fermi-LAT Gamma-ray Observations of IceCube-190523A
  17. GRB200521A: ASIM observation
  18. GRB 200524A: Swift-XRT afterglow detection
  19. GRB 200524A: OAJ multicolor afterglow detection
  20. GRB 200524A: Fermi GBM detection
  21. GRB 200524A: 1.3m DFOT Optical Observation of ZTF20abbiixp
  22. GRB 200524A: 3.6m DOT observations of the afterglow candidate ZTF20abbiixp
  23. GRB 200524A: Fermi-LAT detection
  24. GRB 200522A: Swift-XRT refined Analysis
  25. GRB 200517A: Swift-XRT Confirmation of afterglow
  26. GRB 200514B: Fermi GBM observation
  27. GRB 200519A: 1.3m DFOT Optical Afterglow Detection
  28. GRB 200519A: Swift-XRT refined Analysis
  29. GRB 200519A: iTelescope optical afterglow detection
  30. GRB 200517A: Swift-XRT afterglow detection
  31. GRB 200512A: Swift-XRT refined Analysis
  32. Fermi-LAT Gamma-ray Observations of IceCube-200512A
  33. IceCube-200512A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  34. GRB 200509A: Swift-XRT refined Analysis
  35. GRB 200424A: Swift-XRT afterglow detection
  36. SGR 1935+2154 the Insight-HXMT observation plan
  37. IceCube-200425A: No significant detection in HAWC
  38. Fermi-LAT Gamma-ray Observations of IceCube-200425A
  39. IceCube-200425A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  40. GRB 200424A: Swift/UVOT Upper Limits
  41. GRB 200425A: Swift-XRT refined Analysis
  42. GRB 200424A: Swift-XRT observations
  43. GRB 200415A (possible magnetar Giant Flare in Sculptor Galaxy): INTEGRAL observations
  44. Fermi-LAT Gamma-ray Observations of IceCube-200421A
  45. IceCube-200421A: No significant detection in HAWC
  46. IceCube-200421A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  47. GRB 200410A: Optical upper limit
  48. GRB 200412B: Swift XRT confirmation of afterglow and UVOT upper limits
  49. GRB 200415A: Fermi-LAT localization update
  50. GRB 200416A: Fermi GBM observation
  51. GRB 200415A: Fermi GBM observation
  52. GRB 200415A: Fermi-LAT detection
  53. GRB 200412B: Xinglong TNT optical observations
  54. GRB 200412B: SAO RAS observations of OT
  55. IceCube-200410A: No significant detection in HAWC
  56. GRB 200405B: Further Swift-XRT observations
  57. GRB 200412B: Swift-XRT afterglow detection
  58. GRB 200412B: Fermi GBM detection
  59. GRB 200412B: Fermi-LAT detection
  60. GRB 200412A: Fermi GBM detection
  61. Fermi-LAT Gamma-ray Observations of IceCube-200410A
  62. GRB 200411A: Fermi GBM observation
  63. GRB 200411A: Swift-XRT refined Analysis
  64. IceCube-200410A: Possible associated excess in INTEGRAL SPI-ACS prompt observation
  65. SGR 1935+2154: Fermi GBM observation
  66. LIGO/Virgo S200225q: Swift XRT observations, 1 X-ray sources
  67. LIGO/Virgo S200224ca: Swift XRT observations, 8 X-ray sources
  68. GRB 200410A: Swift-XRT refined Analysis
  69. GRB 200409A: Swift-XRT refined Analysis
  70. GRB 200405B: Swift-XRT observations
  71. LIGO/Virgo S200316bj: Upper limits from Konus-Wind observations
  72. LIGO/Virgo S200311bg: Upper limits from Konus-Wind observations
  73. LIGO/Virgo S200302c: Upper limits from Konus-Wind observations
  74. LIGO/Virgo S200225q: Upper limits from Konus-Wind observations
  75. LIGO/Virgo S200224ca: Upper limits from Konus-Wind observations
  76. GRB 200325B: Optical upper limit
  77. GRB 200325B: further Swift-XRT observations
  78. GRB 200327A: Fermi GBM detection
  79. GRB 200325B: Fermi GBM observation
  80. GRB 200325B: Swift-XRT and UVOT observations
  81. GRB 200325A: Fermi GBM observation
  82. GRB 200324A: AROMA-N Optical Observation
  83. GRB 200324A: Swift-XRT refined Analysis
  84. GRB 200324A: NOT optical upper limit
  85. GRB 200323A: Fermi GBM detection
  86. Chandra observations of GW170817 at 2.5 years since merger (All epochs 4 of 4)
  87. GW170817: Continued X-ray emission detected with Chandra at 940 days post-merger
  88. LIGO/Virgo S200316bj: No counterpart candidates in Fermi-LAT observations
  89. LIGO/Virgo S200213t: Continued Swift UVOT and XRT observations of ZTF20aamvmzj (AT2020cja)
  90. LIGO/Virgo S200316bj: No counterpart candidates in INTEGRAL SPI-ACS, and IBIS prompt observation
  91. LIGO/Virgo S200316bj: upper limits from AGILE/MCAL observations
  92. GRB 200313A: Fermi GBM detection
  93. LIGO/Virgo S200311bg: No significant counterpart candidates in Fermi-LAT observations
  94. LIGO/Virgo S200311bg: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  95. Chandra observations of GW170817 ~ 2.5 years since merger (epoch 1 of 4)
  96. GRB 200306C: Swift-XRT refined Analysis
  97. GRB 200306A: Swift-XRT refined Analysis
  98. GRB 200303A: Fermi GBM observation
  99. GRB 200303A: Swift-XRT refined Analysis
  100. LIGO/Virgo S200302c: No significant counterpart candidates in Fermi-LAT observations

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