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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"

11525 results found.

  1. GRB 200219C: Fermi GBM Final Real-time Localization
  2. LIGO/Virgo S200219ac: Fermi GBM transient event not confidently associated with GW signal
  3. LIGO/Virgo S200219ac: No counterpart candidates in Fermi-LAT observations
  4. GRB 200219A: Fermi GBM observation
  5. GRB 200216B: second epoch optical upper limit at Mondy observatory
  6. GRB 200219B: Fermi GBM Final Real-time Localization
  7. GRB 200219A: Fermi GBM Final Real-time Localization
  8. GRB 200216B: Mondy and AbAO optical upper limits
  9. GRB 200215A: CALET Gamma-Ray Burst Monitor detection
  10. GRB 200216A: Fermi GBM detection
  11. GRB 200216B: z-band limit from NOT
  12. GRB 200216B: Fermi GBM observation
  13. GRB 200216A: Swift/BAT detection and arcminute localization from GUANO
  14. GRB 200216B: Fermi GBM Final Real-time Localization
  15. GRB 200216A: Fermi GBM Final Real-time Localization
  16. GRB 200215A: Fermi GBM detection
  17. GRB 200215A: Fermi GBM Final Real-time Localization
  18. LIGO/Virgo S200213t: No counterpart candidates in Fermi-LAT observations
  19. LIGO/Virgo S200213t: not observable by Fermi-GBM
  20. GRB 2002011A: AstroSat CZTI detection
  21. GRB 200212A: Fermi GBM Final Localization Correction
  22. Fermi trigger No 603197394: Global MASTER-Net observations report
  23. GRB 200212A: Fermi GBM Final Real-time Localization
  24. GRB 200211A: BALROG localization (Fermi Trigger 603098793 / GRB 200211310)
  25. GRB 200211A: Fermi GBM Final Real-time Localization
  26. GRB 200207A: AstroSat CZTI detection
  27. LIGO/Virgo S200208q: No counterpart candidates in Fermi-LAT observations
  28. GRB 200120A: Fermi GBM observation
  29. LIGO/Virgo S200208q: Upper limits from Fermi-GBM Observations
  30. Fermi trigger No 602817262: Global MASTER-Net observations report
  31. GRB 200208A: Fermi GBM Final Real-time Localization
  32. Fermi trigger No 602731380: Global MASTER-Net observations report
  33. GRB 200207A: Fermi GBM Final Real-time Localization
  34. GRB 200206A: Fermi GBM Final Real-time Localization
  35. Fermi trigger No 602626648: Global MASTER-Net observations report
  36. GRB 200205C: Fermi GBM Final Real-time Localization
  37. GRB200120A: SRG/eROSITA discovery of X-ray afterglow
  38. Fermi trigger No 602455182: Global MASTER-Net observations report
  39. Re-classification of Fermi GBM triggers 200203137, 200203156/GRB200203A and 200203861
  40. GRB200120A: SRG/ART-XC Upper Limit
  41. Fermi trigger No 602392636: Global MASTER-Net observations report
  42. ZTF20aajnksq: Occulted by Earth at the time of GRB 200128A
  43. GRB 200203A: Fermi GBM Final Real-time Localization
  44. ZTF Discovery of ZTF20aajnksq: a Rapidly Fading Luminous Transient in the GRB 200128A Localiziation Region
  45. GRB 200201A: Fermi GBM Final Real-time Localization
  46. Konus-Wind observation of GRB 200125B
  47. Konus-Wind observation of GRB 200130B
  48. IPN triangulation of GRB 200130B
  49. Fermi trigger No 602071201: Global MASTER-Net observations report
  50. GRB 200130B: BALROG localization (Fermi Trigger 602071201 / GRB 200130417)
  51. GRB 200130B: Fermi GBM Final Real-time Localization
  52. Fermi trigger No 602056641: Global MASTER-Net observations report
  53. GRB 200130A: Fermi GBM Final Real-time Localization
  54. LIGO/Virgo S200129m: No counterpart candidates in Fermi-LAT observations
  55. LIGO/Virgo S200129m: Not observable by Fermi-GBM
  56. GRB 200129A: Fermi GBM Final Real-time Localization
  57. LIGO/Virgo S200128d: No counterpart candidates in Fermi-LAT observations
  58. Fermi-LAT ANTARES coincidence: IceCube neutrino search
  59. Fermi-LAT ANTARES 200127.79 coincidence: MASTER alert observation and presence of young pulsar close to error-box
  60. IPN triangulation of GRB 200125B
  61. LIGO/Virgo S200128d: Upper limits from Fermi-GBM Observations
  62. Fermi-LAT-ANTARES coincidence
  63. GRB 200125B: DDOTI/OAN optical observations report
  64. GRB 200128A: Fermi GBM Final Real-time Localization
  65. Fermi trigger No 601841483: Global MASTER-Net observations report
  66. GRB 200127B: Fermi GBM Final Real-time Localization
  67. GRB 200125B: Fermi GBM observations
  68. Fermi trigger No 601729856: Global MASTER-Net observations report
  69. GRB 200125B: Insight-HXMT/HE detection
  70. Fermi trigger No 601677816: Global MASTER-Net observations report
  71. GRB 200125B: BALROG localization (Fermi Trigger 601677816 / GRB 200125864)
  72. GRB 200125B: Fermi GBM Final Real-time Localization
  73. GRB 200122B: Insight-HXMT/HE detection
  74. Fermi trigger No 601363105: Global MASTER-Net observations report
  75. Konus-Wind observation of GRB 200120A
  76. IPN Triangulation of GRB 200120A
  77. GRB 200120A: AstroSat CZTI detection
  78. Fermi-LAT Gamma-ray Observations of IceCube-200120A
  79. Fermi trigger No 601254300: Global MASTER-Net observations report
  80. GRB 191031D: XMM-Newton upper limit
  81. GRB 200120A: Insight-HXMT/HE detection
  82. IceCube-200120A: not observable by Fermi-GBM
  83. GRB 200120A: Fermi GBM Final Real-time Localization
  84. Fermi-LAT Gamma-ray Observations of IceCube-200117A
  85. IceCube-200117A: Upper limits from Fermi-GBM Observations
  86. GRB 200117A: Fermi GBM Final Real-time Localization
  87. GRB 200111A: CALET Gamma-Ray Burst Monitor detection
  88. GRB 200111A: AstroSat CZTI detection
  89. IPN triangulation of GRB 200111A
  90. LIGO/Virgo S200115j: No counterpart candidates in Fermi-LAT observations
  91. LIGO/Virgo S200115j: Upper limits from Fermi-GBM Observations
  92. GRB 200114A: Insight-HXMT/HE detection
  93. GRB 200114A: DDOTI/OAN optical observations report
  94. GRB 200114A: AstroSat CZTI detection
  95. LIGO/Virgo S200114f: No counterpart candidates in Fermi-LAT observations
  96. LIGO/Virgo S200114f: Upper limits from Fermi-GBM Observations
  97. Fermi trigger No 600666048: Global MASTER-Net observations report
  98. GRB 200114A: BALROG localization (Fermi Trigger 600666048 / GRB 200114153)
  99. GRB 200114A: Fermi GBM Final Real-time Localization
  100. GRB 200112A: AstroSat CZTI detection

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