Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

3040 results found.

  1. GRB 190829A, Swift-BAT refined analysis
  2. GRB 190829A:: Global MASTER-net optical clear and polarization observations scheduler and some spiculations
  3. GRB 190829A: GROND detection of the Optical/NIR Afterglow
  4. GRB 190829A: Enhanced Swift-XRT position
  5. LIGO/Virgo S190828j: No Counterparts in DDOTI/OAN Optical Observations
  6. LIGO/Virgo S190828l: No counterpart candidates in KAIT observations
  7. GRB 190829A: Dabancheng-0.5m optical afterglow detection
  8. GRB 190829A: Swift detection of a burst consistent with a galaxy at z=0.08
  9. LIGO/Virgo S190828j: No counterpart candidates in KAIT observations
  10. GRB 190828A: MAXI/GSC detection
  11. LIGO/Virgo S190814bv: MASTER prediscovery and postdiscovery observations DECam candidate DG19wxnjc/AT2019npv field
  12. Fermi trigger No 588350802 Global MASTER-Net observations report
  13. GRB 190823A: MAXI/GSC detection
  14. Fermi trigger No 588185734 Global MASTER-Net observations report
  15. Fermi GBM-190816: MASTER-Net optical observation report
  16. LIGO/Virgo S190814bv: No radio counterpart detected in ASKAP observations
  17. LIGO/Virgo S190814bv: No Optical Counterpart Candidates in Second-Epoch Lick/KAIT Observations
  18. LIGO/Virgo S190814bv: RATIR Optical observations of DECam transients
  19. LIGO/Virgo S190814bv : No Counterpart Candidates in Continued Galaxy Targeted Search with Magellan
  20. LIGO/Virgo S190814bv: No candidates from DCT galaxy targeted search and observations of DECam-GROWTH candidates
  21. LIGO/Virgo S190814bv : No Counterpart Candidates in Galaxy Targeted Search with Magellan
  22. Fermi trigger No 587505927 Global MASTER-Net observations report
  23. LIGO/Virgo S190814bv: No counterpart candidates in KAIT observations
  24. LIGO/Virgo S190814bv Global MASTER-Net optical observations
  25. LIGO/Virgo S190814bv: Nordic Optical Telescope imaging of selected galaxies
  26. Fermi trigger No 587392154 Global MASTER-Net observations report
  27. LIGO/Virgo S190808ae: Identification of a GW compact binary merger candidate
  28. Fermi trigger No 586676451 Global MASTER-Net observations report
  29. GRB 190805B: MAXI/GSC detection
  30. GRB 190804B: MAXI/GSC detection
  31. Fermi trigger No 586574612 Global MASTER-Net observations report
  32. IPN Triangulation of GRB 190731A
  33. LIGO/Virgo S190728q: No counterpart candidates in KAIT observations
  34. LIGO/Virgo S190728q: no counterpart candidates in AGILE-GRID observations
  35. LIGO/Virgo S190728q Global MASTER-Net observations report
  36. LIGO/Virgo S190727h: No counterpart candidates in KAIT observations
  37. Fermi trigger No 585864875 Global MASTER-Net observations report
  38. Fermi trigger No 585856427 Global MASTER-Net observations report
  39. LIGO/Virgo S190720a: Thacher Observatory follow-up observations
  40. IPN triangulation of GRB 190724A (short)
  41. LIGO/Virgo S190720a: No counterpart candidates in KAIT observations
  42. LIGO/Virgo S190720a: Upper limits from Fermi-GBM Observations
  43. LIGO/Virgo S190718y: No counterpart candidates in CNEOST
  44. LIGO/Virgo S190718y: No counterpart candidates in KAIT observations
  45. Swift GRB190718.2 Global MASTER-Net observations report
  46. Fermi trigger No 585007213 Global MASTER-Net observations report
  47. Fermi trigger No 584929684 Global MASTER-Net observations report
  48. GRB 190714A: MAXI/GSC detection
  49. Fermi trigger No 584637077 Global MASTER-Net observations report
  50. LIGO/Virgo S190706ai: Upper limits from Insight-HXMT/HE observations
  51. MAXI GRB190708.83 Global MASTER-Net observations report
  52. LIGO/Virgo S190706ai: No counterpart candidates in KAIT observations
  53. GRB 190706A: MAXI/GSC detection
  54. Fermi trigger No 584007338 Global MASTER-Net observations report
  55. LIGO/Virgo S190630ag: no counterpart candidate in the SVOM/GWAC observations
  56. GRB 190630C: Swift-BAT refined analysis
  57. GRB 190701A: MAXI/GSC detection
  58. Fermi trigger No 583567803 Global MASTER-Net observations report
  59. GRB 190627A: Koshka Zeiss-1000 optical counterpart observations
  60. Fermi trigger No 583327924 Global MASTER-Net observations report
  61. Fermi trigger No 582856902 Global MASTER-Net observations report
  62. Fermi trigger No 582759998 Global MASTER-Net observations report
  63. Fermi trigger No 582615488 Global MASTER-Net observations report
  64. Fermi trigger No 582115625 Global MASTER-Net observations report
  65. IPN Triangulation of GRB 190611B
  66. GRB 190612A: Fermi GBM Final Real-time Localization
  67. Fermi trigger No 581889628 Global MASTER-Net observations report
  68. GRB 190610A: Swift detection of a short burst
  69. Fermi trigger No 581645543 Global MASTER-Net observations report
  70. IPN Triangulation of GRB 190606A (short)
  71. GRB 190604B: BOOTES-3 early optical limits
  72. GRB 190604B: Swift detection of a burst
  73. LIGO/Virgo S190602aq: No counterpart candidates in HAWC observations
  74. GRB 190530A: Mondy and AbAO optical observations
  75. GRB 190531B: VLT optical upper limit
  76. GRB 190531B: MASTER optical observation
  77. GRB 190531B: Swift-XRT afterglow detection
  78. LIGO/Virgo S190425z: No counterpart candidate in Zadko-GRANDMA observations.
  79. LIGO/Virgo S190521r : Gaia Photometric Alerts transient candidate
  80. LIGO/Virgo S190521r: CNEOST follow-up observations
  81. Fermi GRB190525.67 Global MASTER-Net observations report
  82. Fermi GRB190525.03 Global MASTER-Net observations report
  83. LIGO/Virgo S190521r: No optical counterpart from SVOM/GWAC-F30 observations.
  84. LIGO/Virgo S190521g: No optical counterpart from SVOM/GWAC observations.
  85. LIGO/Virgo S190519bj Global MASTER-Net observations report
  86. GRB 190519A: Swift-BAT refined analysis
  87. GRB 190519A: Fermi GBM Final Real-time Localization
  88. Fermi GRB190517.81 Global MASTER-Net observations report
  89. LIGO/Virgo S190517h Global MASTER-Net observations report
  90. LIGO/Virgo S190513bm: Swope follow-up observations
  91. LIGO/Virgo S190513bm: Lick/KAIT Follow-Up Observations
  92. Konus-Wind observation of GRB 190511A
  93. LIGO/Virgo S190510g: Further KMTNet observation of DECam-GROWTH and DESGW candidates
  94. LIGO/Virgo S190512at Global MASTER-Net observations report
  95. Fermi GRB190512.61 Global MASTER-Net observations report
  96. LIGO/Virgo S190510g: DOAO Observation
  97. LIGO/Virgo S190510g: KMTNet observation of DECam-GROWTH and DESGW candidates
  98. LIGO/Virgo S190510g: Las Cumbres Observatory Galaxy Targeted Counterpart Search
  99. LIGO/Virgo S190510g: GRAWITA REM and Loiano optical observations
  100. LIGO/Virgo S190510g: GRAWITA VST-ESO PARANAL optical observations

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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