Skip to main content
New! BOOM Notices and Schema v7.0.0. See news and announcements

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"

11049 results found.

  1. LIGO/Virgo S200225q: No counterpart candidates in Fermi-LAT observations
  2. LIGO/Virgo S200224ca: No counterpart candidates in Fermi-LAT observations
  3. LIGO/Virgo S200224ca: not observable by Fermi-GBM
  4. IPN triangulation of GRB 200224C
  5. Correction in name: GRB 200224B and GRB 200224C (not GRB 200224A)
  6. GRB 200219C: Swift-XRT afterglow confirmation
  7. GRB 200224C: Fermi GBM Final Real-time Localization
  8. Fermi trigger No 604213554: Global MASTER-Net observations report
  9. GRB 200224B: Fermi GBM Final Real-time Localization
  10. GRB 200223A: Fermi GBM Final Real-time Localization
  11. IPN triangulation of GRB 200219B (inconsistent with the LIGO/Virgo S200219ac)
  12. GRB 200219C: OAJ afterglow confirmation
  13. GRB 200219C: CALET Gamma-Ray Burst Monitor detection
  14. GRB 200219C: Mondy and TSHAO optical observations
  15. GRB 200219C: Nanshan/NEXT optical upper limit and possible host galaxy from PanSTARRS
  16. GRB 200221A: Fermi GBM Final Real-time Localization
  17. Fermi trigger No 603949983: Global MASTER-Net observations report
  18. GRB 200219C: Swift-XRT afterglow detection
  19. GRB 200219C: DDOTI Observations
  20. GRB 200219C: Fermi GBM detection
  21. GRB 200219C: Tiled Swift observations
  22. GRB 200219C: Fermi-LAT detection
  23. LIGO/Virgo S200219ac: no counterpart candidates in the Swift/BAT observations
  24. Fermi trigger No 603849435: Global MASTER-Net observations report
  25. GRB 200219C: Fermi GBM Final Real-time Localization
  26. LIGO/Virgo S200219ac: Fermi GBM transient event not confidently associated with GW signal
  27. LIGO/Virgo S200219ac: No counterpart candidates in Fermi-LAT observations
  28. GRB 200219A: Fermi GBM observation
  29. GRB 200216B: second epoch optical upper limit at Mondy observatory
  30. GRB 200219B: Fermi GBM Final Real-time Localization
  31. GRB 200219A: Fermi GBM Final Real-time Localization
  32. GRB 200216B: Mondy and AbAO optical upper limits
  33. GRB 200215A: CALET Gamma-Ray Burst Monitor detection
  34. GRB 200216A: Fermi GBM detection
  35. GRB 200216B: z-band limit from NOT
  36. GRB 200216B: Fermi GBM observation
  37. GRB 200216A: Swift/BAT detection and arcminute localization from GUANO
  38. GRB 200216B: Fermi GBM Final Real-time Localization
  39. GRB 200216A: Fermi GBM Final Real-time Localization
  40. GRB 200215A: Fermi GBM detection
  41. GRB 200215A: Fermi GBM Final Real-time Localization
  42. LIGO/Virgo S200213t: No counterpart candidates in Fermi-LAT observations
  43. LIGO/Virgo S200213t: not observable by Fermi-GBM
  44. GRB 2002011A: AstroSat CZTI detection
  45. GRB 200212A: Fermi GBM Final Localization Correction
  46. Fermi trigger No 603197394: Global MASTER-Net observations report
  47. GRB 200212A: Fermi GBM Final Real-time Localization
  48. GRB 200211A: BALROG localization (Fermi Trigger 603098793 / GRB 200211310)
  49. GRB 200211A: Fermi GBM Final Real-time Localization
  50. GRB 200207A: AstroSat CZTI detection
  51. LIGO/Virgo S200208q: No counterpart candidates in Fermi-LAT observations
  52. GRB 200120A: Fermi GBM observation
  53. LIGO/Virgo S200208q: Upper limits from Fermi-GBM Observations
  54. Fermi trigger No 602817262: Global MASTER-Net observations report
  55. GRB 200208A: Fermi GBM Final Real-time Localization
  56. Fermi trigger No 602731380: Global MASTER-Net observations report
  57. GRB 200207A: Fermi GBM Final Real-time Localization
  58. GRB 200206A: Fermi GBM Final Real-time Localization
  59. Fermi trigger No 602626648: Global MASTER-Net observations report
  60. GRB 200205C: Fermi GBM Final Real-time Localization
  61. GRB200120A: SRG/eROSITA discovery of X-ray afterglow
  62. Fermi trigger No 602455182: Global MASTER-Net observations report
  63. Re-classification of Fermi GBM triggers 200203137, 200203156/GRB200203A and 200203861
  64. GRB200120A: SRG/ART-XC Upper Limit
  65. Fermi trigger No 602392636: Global MASTER-Net observations report
  66. ZTF20aajnksq: Occulted by Earth at the time of GRB 200128A
  67. GRB 200203A: Fermi GBM Final Real-time Localization
  68. ZTF Discovery of ZTF20aajnksq: a Rapidly Fading Luminous Transient in the GRB 200128A Localiziation Region
  69. GRB 200201A: Fermi GBM Final Real-time Localization
  70. Konus-Wind observation of GRB 200125B
  71. Konus-Wind observation of GRB 200130B
  72. IPN triangulation of GRB 200130B
  73. Fermi trigger No 602071201: Global MASTER-Net observations report
  74. GRB 200130B: BALROG localization (Fermi Trigger 602071201 / GRB 200130417)
  75. GRB 200130B: Fermi GBM Final Real-time Localization
  76. Fermi trigger No 602056641: Global MASTER-Net observations report
  77. GRB 200130A: Fermi GBM Final Real-time Localization
  78. LIGO/Virgo S200129m: No counterpart candidates in Fermi-LAT observations
  79. LIGO/Virgo S200129m: Not observable by Fermi-GBM
  80. GRB 200129A: Fermi GBM Final Real-time Localization
  81. LIGO/Virgo S200128d: No counterpart candidates in Fermi-LAT observations
  82. Fermi-LAT ANTARES coincidence: IceCube neutrino search
  83. Fermi-LAT ANTARES 200127.79 coincidence: MASTER alert observation and presence of young pulsar close to error-box
  84. IPN triangulation of GRB 200125B
  85. LIGO/Virgo S200128d: Upper limits from Fermi-GBM Observations
  86. Fermi-LAT-ANTARES coincidence
  87. GRB 200125B: DDOTI/OAN optical observations report
  88. GRB 200128A: Fermi GBM Final Real-time Localization
  89. Fermi trigger No 601841483: Global MASTER-Net observations report
  90. GRB 200127B: Fermi GBM Final Real-time Localization
  91. GRB 200125B: Fermi GBM observations
  92. Fermi trigger No 601729856: Global MASTER-Net observations report
  93. GRB 200125B: Insight-HXMT/HE detection
  94. Fermi trigger No 601677816: Global MASTER-Net observations report
  95. GRB 200125B: BALROG localization (Fermi Trigger 601677816 / GRB 200125864)
  96. GRB 200125B: Fermi GBM Final Real-time Localization
  97. GRB 200122B: Insight-HXMT/HE detection
  98. Fermi trigger No 601363105: Global MASTER-Net observations report
  99. Konus-Wind observation of GRB 200120A
  100. IPN Triangulation of GRB 200120A

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov