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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"

6828 results found.

  1. GRB 200327A: Fermi GBM detection
  2. GRB 200325B: Fermi GBM observation
  3. GRB 200325B: Swift-XRT and UVOT observations
  4. GRB 200325A: Fermi GBM observation
  5. GRB 200324A: AROMA-N Optical Observation
  6. GRB 200324A: Swift-XRT refined Analysis
  7. GRB 200324A: NOT optical upper limit
  8. GRB 200323A: Fermi GBM detection
  9. Chandra observations of GW170817 at 2.5 years since merger (All epochs 4 of 4)
  10. GW170817: Continued X-ray emission detected with Chandra at 940 days post-merger
  11. LIGO/Virgo S200316bj: No counterpart candidates in Fermi-LAT observations
  12. LIGO/Virgo S200213t: Continued Swift UVOT and XRT observations of ZTF20aamvmzj (AT2020cja)
  13. LIGO/Virgo S200316bj: No counterpart candidates in INTEGRAL SPI-ACS, and IBIS prompt observation
  14. LIGO/Virgo S200316bj: upper limits from AGILE/MCAL observations
  15. GRB 200313A: Fermi GBM detection
  16. LIGO/Virgo S200311bg: No significant counterpart candidates in Fermi-LAT observations
  17. LIGO/Virgo S200311bg: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  18. Chandra observations of GW170817 ~ 2.5 years since merger (epoch 1 of 4)
  19. GRB 200306C: Swift-XRT refined Analysis
  20. GRB 200306A: Swift-XRT refined Analysis
  21. GRB 200303A: Fermi GBM observation
  22. GRB 200303A: Swift-XRT refined Analysis
  23. LIGO/Virgo S200302c: No significant counterpart candidates in Fermi-LAT observations
  24. LIGO/Virgo S200302c: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  25. LIGO/Virgo S200302c: upper limits from AGILE/MCAL observations
  26. GRB 200228B: Swift-XRT refined Analysis
  27. GRB 200228B: Fermi GBM observation
  28. GRB 200228A: Fermi GBM observation
  29. LIGO/Virgo S200213t: No significant EM counterparts identified from continued GECKO observation of host galaxy candidates
  30. Fermi-LAT Gamma-ray Observations of IceCube-200227A
  31. GRB 200227A: Swift-XRT refined Analysis
  32. GRB 200227A: Fermi GBM observation
  33. IceCube-200227A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  34. LIGO/Virgo S200219ac: Upper limits from Konus-Wind observations
  35. LIGO/Virgo S200213t: Upper limits from Konus-Wind observations
  36. LIGO/Virgo S200208q: Upper limits from Konus-Wind observations
  37. LIGO/Virgo S200225q: No counterpart candidates in Fermi-LAT observations
  38. LIGO/Virgo S200225q: upper limits from AGILE/MCAL observations
  39. LIGO/Virgo S200224ca: No counterpart candidates in Fermi-LAT observations
  40. LIGO/Virgo S200225q: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  41. LIGO/Virgo S200224ca: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  42. LIGO/Virgo S200224ca: upper limits from AGILE/MCAL observations
  43. GRB 200219C: Swift-XRT afterglow confirmation
  44. GRB 200224A: Swift-XRT refined Analysis
  45. GRB 200219C: OAJ afterglow confirmation
  46. GRB 200219C: Swift-XRT afterglow detection
  47. GRB 200219C: Fermi GBM detection
  48. LIGO/Virgo S200213t: Swift UVOT and XRT observations of ZTF20aamvmzj (AT2020cja)
  49. GRB 200219C: Fermi-LAT detection
  50. GRB 200219A, Swift-BAT refined analysis
  51. LIGO/Virgo S200219ac: No counterpart candidates in Fermi-LAT observations
  52. GRB 200219A: Swift-XRT refined Analysis correction
  53. GRB 200219A: Swift-XRT refined Analysis
  54. GRB 200219A: Fermi GBM observation
  55. LIGO/Virgo S200219ac: upper limits from AGILE/MCAL observations
  56. LIGO/Virgo S200219ac: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  57. GRB 200216B: Swift-XRT refined Analysis
  58. Further Swift-XRT observations of Swift J0840.7-3516
  59. GRB 200215A: Swift-XRT refined Analysis
  60. GRB 200215A: Fermi GBM detection
  61. LIGO/Virgo S200213t: No candidates found in J-GEM follow-up observations
  62. LIGO/Virgo S200213t: No counterpart candidates in Fermi-LAT observations
  63. LIGO/Virgo S200213t: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  64. ZTF20aajnksq: Upper limits from Konus-Wind observations
  65. LIGO/Virgo S200208q: No counterpart candidates in Fermi-LAT observations
  66. GRB 200120A: Fermi GBM observation
  67. LIGO/Virgo S200208q: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  68. GRB 200205B: ESO/NTT near-infrared imaging
  69. GRB 200205B: Swift-XRT refined Analysis
  70. Swift GRB200205.81: Global MASTER-Net observations report
  71. Swift GRB200205.81: Global MASTER-Net OT detection
  72. LIGO/Virgo S200129m: Upper limits from Konus-Wind observations
  73. LIGO/Virgo S200128d: Upper limits from Konus-Wind observations
  74. GRB 200131A: Swift-XRT refined Analysis
  75. LIGO/Virgo S200129m: No counterpart candidates in Fermi-LAT observations
  76. LIGO/Virgo S200128d: upper limits from AGILE/GRID observations
  77. LIGO/Virgo S200129m: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  78. LIGO/Virgo S200128d: No counterpart candidates in Fermi-LAT observations
  79. GRB 200127A: Swift/UVOT Upper Limits
  80. LIGO/Virgo S200128d: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  81. GRB 200127A: Swift-XRT refined Analysis
  82. GRB 200125A: Swift-BAT refined analysis
  83. GRB 200125A: Further Swift-XRT observations
  84. GRB 200125B: Fermi GBM observations
  85. GRB 200125A: TNG detection of a NIR counterpart candidate
  86. Correction to GRB 200125A: Swift-XRT refined analysis
  87. GRB 200125A: Swift-XRT refined Analysis
  88. LIGO/Virgo S200115j: Zwicky Transient Facility search for optical counterparts to Swift X-ray sources
  89. LIGO/Virgo S200115j: Further Swift-XRT sources
  90. GRB 200122A: Swift-XRT refined Analysis
  91. Fermi-LAT Gamma-ray Observations of IceCube-200120A
  92. LIGO/Virgo S200115j: Upper limits from Konus-Wind observations
  93. LIGO/Virgo S200114f: Upper limits from Konus-Wind observations
  94. LIGO/Virgo S200112r: Upper limits from Konus-Wind observations
  95. GRB 191031D: XMM-Newton upper limit
  96. IceCube-200120A: no counterpart candidates in INTEGRAL SPI-ACS and,IBIS prompt observation
  97. LIGO/Virgo S200105ae: Upper limits from Konus-Wind observations
  98. LIGO/Virgo S191222n: Upper limits from Konus-Wind observations
  99. LIGO/Virgo S191216ap: Upper limits from Konus-Wind observations
  100. LIGO/Virgo S191215w: Upper limits from Konus-Wind observations

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