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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"

11112 results found.

  1. Fermi trigger No 606098435: Global MASTER-Net observations report
  2. GRB 200317A: Fermi GBM Final Real-time Localization
  3. IPN triangulation of GRB 200313B (short)
  4. IPN triangulation of GRB 200313A
  5. GRB 200313A: Fermi GBM detection
  6. IPN triangulation of GRB 200311A
  7. Fermi trigger No 605789837: Global MASTER-Net observations report
  8. GRB 200313B: Fermi GBM Final Real-time Localization
  9. GRB 200313A: BALROG localization (Fermi Trigger 605756501 / GRB 200313071)
  10. Fermi trigger No 605756501: Global MASTER-Net observations report
  11. GRB 200313A: Fermi GBM Final Real-time Localization
  12. GRB 200311A: AstroSat CZTI detection
  13. Fermi trigger No 605632577: Global MASTER-Net observations report
  14. LIGO/Virgo S200311bg: No significant counterpart candidates in Fermi-LAT observations
  15. IPN triangulation of GRB 200307A (short)
  16. GRB 200311A: AGILE/MCAL and scientific ratemeters observations
  17. LIGO/Virgo S200311bg: not observable by Fermi GBM
  18. GRB 200311A: Fermi GBM Final Real-time Localization
  19. GRB 200307A: Updated localization from Fermi/GBM and Swift/BAT-GUANO
  20. GRB 200308A: Fermi GBM Final Real-time Localization
  21. Fermi trigger No 605309224: Global MASTER-Net observations report
  22. GRB 200307A: Fermi GBM Final Real-time Localization
  23. GRB 200306B: Fermi GBM Final Localization Correction
  24. GRB 200306B: Fermi GBM Final Real-time Localization
  25. GRB 200228B: continued optical observations
  26. Konus-Wind observation of GRB200303A
  27. GRB 200303A: Fermi GBM observation
  28. GRB 200303A: NOT optical observations
  29. GRB 200303A: FRAM-ORM optical limit
  30. GRB 200219A: AstroSat CZTI detection
  31. GRB 200303A: GOTO observations upper limit
  32. GRB 200228A: AstroSat CZTI detection
  33. GRB 200303A: CALET Gamma-Ray Burst Monitor detection
  34. GRB 200219C: VLA Detection
  35. Fermi trigger No 604895668: Global MASTER-Net observations report
  36. GRB 200303A: Fermi GBM Final Real-time Localization
  37. LIGO/Virgo S200302c: No significant counterpart candidates in Fermi-LAT observations
  38. LIGO/Virgo S200302c: Upper limits from Fermi-GBM Observations
  39. GRB 200228B: Mondy, TSHAO, AbAO and CrAO optical observations, afterglow candidate
  40. GRB 200228B: RATIR Optical Observations
  41. GRB 200228B: Liverpool Telescope imaging
  42. GRB 200228B: Fermi GBM observation
  43. GRB 200228A: Fermi GBM observation
  44. GRB 200228A: Swift/BAT detection and arcminute localization from GUANO
  45. GRB 200227A: Mondy optical upper limit
  46. Fermi-LAT Gamma-ray Observations of IceCube-200227A
  47. GRB 200228B: Fermi GBM Final Real-time Localization
  48. Fermi trigger No 604565918: Global MASTER-Net observations report
  49. GRB 200227A: Insight-HXMT/HE detection
  50. GRB 200228A: BALROG localization (Fermi Trigger 604565918 / GRB 200228291)
  51. GRB 200228A: Fermi GBM Final Real-time Localization
  52. GRB 200219A: ATCA 5/9 GHz radio observations
  53. IceCube-200227A: Upper limits from Fermi-GBM Observations
  54. GRB 200224A: Mondy optical upper limit
  55. GRB 200227A: Fermi GBM observation
  56. GRB 200227A: MITSuME Akeno optical upper limit
  57. GRB 200227A: Fermi GBM Final Real-time Localization
  58. Konus-Wind observation of GRB 200219C
  59. Konus-Wind observation of GRB 200219A
  60. GRB 200224B: DDOTI/OAN optical observations report
  61. IPN triangulation of GRB 200221A (short)
  62. LIGO/Virgo S200225q: Upper limits from Fermi-GBM Observations
  63. Fermi trigger No 604231129: Global MASTER-Net observations report
  64. LIGO/Virgo S200225q: No counterpart candidates in Fermi-LAT observations
  65. LIGO/Virgo S200224ca: No counterpart candidates in Fermi-LAT observations
  66. LIGO/Virgo S200224ca: not observable by Fermi-GBM
  67. IPN triangulation of GRB 200224C
  68. Correction in name: GRB 200224B and GRB 200224C (not GRB 200224A)
  69. GRB 200219C: Swift-XRT afterglow confirmation
  70. GRB 200224C: Fermi GBM Final Real-time Localization
  71. Fermi trigger No 604213554: Global MASTER-Net observations report
  72. GRB 200224B: Fermi GBM Final Real-time Localization
  73. GRB 200223A: Fermi GBM Final Real-time Localization
  74. IPN triangulation of GRB 200219B (inconsistent with the LIGO/Virgo S200219ac)
  75. GRB 200219C: OAJ afterglow confirmation
  76. GRB 200219C: CALET Gamma-Ray Burst Monitor detection
  77. GRB 200219C: Mondy and TSHAO optical observations
  78. GRB 200219C: Nanshan/NEXT optical upper limit and possible host galaxy from PanSTARRS
  79. GRB 200221A: Fermi GBM Final Real-time Localization
  80. Fermi trigger No 603949983: Global MASTER-Net observations report
  81. GRB 200219C: Swift-XRT afterglow detection
  82. GRB 200219C: DDOTI Observations
  83. GRB 200219C: Fermi GBM detection
  84. GRB 200219C: Tiled Swift observations
  85. GRB 200219C: Fermi-LAT detection
  86. LIGO/Virgo S200219ac: no counterpart candidates in the Swift/BAT observations
  87. Fermi trigger No 603849435: Global MASTER-Net observations report
  88. GRB 200219C: Fermi GBM Final Real-time Localization
  89. LIGO/Virgo S200219ac: Fermi GBM transient event not confidently associated with GW signal
  90. LIGO/Virgo S200219ac: No counterpart candidates in Fermi-LAT observations
  91. GRB 200219A: Fermi GBM observation
  92. GRB 200216B: second epoch optical upper limit at Mondy observatory
  93. GRB 200219B: Fermi GBM Final Real-time Localization
  94. GRB 200219A: Fermi GBM Final Real-time Localization
  95. GRB 200216B: Mondy and AbAO optical upper limits
  96. GRB 200215A: CALET Gamma-Ray Burst Monitor detection
  97. GRB 200216A: Fermi GBM detection
  98. GRB 200216B: z-band limit from NOT
  99. GRB 200216B: Fermi GBM observation
  100. GRB 200216A: Swift/BAT detection and arcminute localization from GUANO

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