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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').
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"

11519 results found.

  1. Fermi trigger No 606263732: Global MASTER-Net observations report
  2. GRB 200318A: Fermi GBM Final Real-time Localization
  3. Konus-Wind observation of GRB 200313B
  4. LIGO/Virgo S200316bj: No counterpart candidates in Fermi-LAT observations
  5. Konus-Wind observation of GRB 200313A
  6. Konus-Wind observation of GRB 200311A
  7. LIGO/Virgo S200316bj: Upper limits from Fermi-GBM Observations
  8. Fermi trigger No 606098435: Global MASTER-Net observations report
  9. GRB 200317A: Fermi GBM Final Real-time Localization
  10. IPN triangulation of GRB 200313B (short)
  11. IPN triangulation of GRB 200313A
  12. GRB 200313A: Fermi GBM detection
  13. IPN triangulation of GRB 200311A
  14. Fermi trigger No 605789837: Global MASTER-Net observations report
  15. GRB 200313B: Fermi GBM Final Real-time Localization
  16. GRB 200313A: BALROG localization (Fermi Trigger 605756501 / GRB 200313071)
  17. Fermi trigger No 605756501: Global MASTER-Net observations report
  18. GRB 200313A: Fermi GBM Final Real-time Localization
  19. GRB 200311A: AstroSat CZTI detection
  20. Fermi trigger No 605632577: Global MASTER-Net observations report
  21. LIGO/Virgo S200311bg: No significant counterpart candidates in Fermi-LAT observations
  22. IPN triangulation of GRB 200307A (short)
  23. GRB 200311A: AGILE/MCAL and scientific ratemeters observations
  24. LIGO/Virgo S200311bg: not observable by Fermi GBM
  25. GRB 200311A: Fermi GBM Final Real-time Localization
  26. GRB 200307A: Updated localization from Fermi/GBM and Swift/BAT-GUANO
  27. GRB 200308A: Fermi GBM Final Real-time Localization
  28. Fermi trigger No 605309224: Global MASTER-Net observations report
  29. GRB 200307A: Fermi GBM Final Real-time Localization
  30. GRB 200306B: Fermi GBM Final Localization Correction
  31. GRB 200306B: Fermi GBM Final Real-time Localization
  32. GRB 200228B: continued optical observations
  33. Konus-Wind observation of GRB200303A
  34. GRB 200303A: Fermi GBM observation
  35. GRB 200303A: NOT optical observations
  36. GRB 200303A: FRAM-ORM optical limit
  37. GRB 200219A: AstroSat CZTI detection
  38. GRB 200303A: GOTO observations upper limit
  39. GRB 200228A: AstroSat CZTI detection
  40. GRB 200303A: CALET Gamma-Ray Burst Monitor detection
  41. GRB 200219C: VLA Detection
  42. Fermi trigger No 604895668: Global MASTER-Net observations report
  43. GRB 200303A: Fermi GBM Final Real-time Localization
  44. LIGO/Virgo S200302c: No significant counterpart candidates in Fermi-LAT observations
  45. LIGO/Virgo S200302c: Upper limits from Fermi-GBM Observations
  46. GRB 200228B: Mondy, TSHAO, AbAO and CrAO optical observations, afterglow candidate
  47. GRB 200228B: RATIR Optical Observations
  48. GRB 200228B: Liverpool Telescope imaging
  49. GRB 200228B: Fermi GBM observation
  50. GRB 200228A: Fermi GBM observation
  51. GRB 200228A: Swift/BAT detection and arcminute localization from GUANO
  52. GRB 200227A: Mondy optical upper limit
  53. Fermi-LAT Gamma-ray Observations of IceCube-200227A
  54. GRB 200228B: Fermi GBM Final Real-time Localization
  55. Fermi trigger No 604565918: Global MASTER-Net observations report
  56. GRB 200227A: Insight-HXMT/HE detection
  57. GRB 200228A: BALROG localization (Fermi Trigger 604565918 / GRB 200228291)
  58. GRB 200228A: Fermi GBM Final Real-time Localization
  59. GRB 200219A: ATCA 5/9 GHz radio observations
  60. IceCube-200227A: Upper limits from Fermi-GBM Observations
  61. GRB 200224A: Mondy optical upper limit
  62. GRB 200227A: Fermi GBM observation
  63. GRB 200227A: MITSuME Akeno optical upper limit
  64. GRB 200227A: Fermi GBM Final Real-time Localization
  65. Konus-Wind observation of GRB 200219C
  66. Konus-Wind observation of GRB 200219A
  67. GRB 200224B: DDOTI/OAN optical observations report
  68. IPN triangulation of GRB 200221A (short)
  69. LIGO/Virgo S200225q: Upper limits from Fermi-GBM Observations
  70. Fermi trigger No 604231129: Global MASTER-Net observations report
  71. LIGO/Virgo S200225q: No counterpart candidates in Fermi-LAT observations
  72. LIGO/Virgo S200224ca: No counterpart candidates in Fermi-LAT observations
  73. LIGO/Virgo S200224ca: not observable by Fermi-GBM
  74. IPN triangulation of GRB 200224C
  75. Correction in name: GRB 200224B and GRB 200224C (not GRB 200224A)
  76. GRB 200219C: Swift-XRT afterglow confirmation
  77. GRB 200224C: Fermi GBM Final Real-time Localization
  78. Fermi trigger No 604213554: Global MASTER-Net observations report
  79. GRB 200224B: Fermi GBM Final Real-time Localization
  80. GRB 200223A: Fermi GBM Final Real-time Localization
  81. IPN triangulation of GRB 200219B (inconsistent with the LIGO/Virgo S200219ac)
  82. GRB 200219C: OAJ afterglow confirmation
  83. GRB 200219C: CALET Gamma-Ray Burst Monitor detection
  84. GRB 200219C: Mondy and TSHAO optical observations
  85. GRB 200219C: Nanshan/NEXT optical upper limit and possible host galaxy from PanSTARRS
  86. GRB 200221A: Fermi GBM Final Real-time Localization
  87. Fermi trigger No 603949983: Global MASTER-Net observations report
  88. GRB 200219C: Swift-XRT afterglow detection
  89. GRB 200219C: DDOTI Observations
  90. GRB 200219C: Fermi GBM detection
  91. GRB 200219C: Tiled Swift observations
  92. GRB 200219C: Fermi-LAT detection
  93. LIGO/Virgo S200219ac: no counterpart candidates in the Swift/BAT observations
  94. Fermi trigger No 603849435: Global MASTER-Net observations report
  95. GRB 200219C: Fermi GBM Final Real-time Localization
  96. LIGO/Virgo S200219ac: Fermi GBM transient event not confidently associated with GW signal
  97. LIGO/Virgo S200219ac: No counterpart candidates in Fermi-LAT observations
  98. GRB 200219A: Fermi GBM observation
  99. GRB 200216B: second epoch optical upper limit at Mondy observatory
  100. GRB 200219B: Fermi GBM Final Real-time Localization

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