Skip to main content
New! CHIME and DSA-110 FRB Notices, IceCube Notices and Schema v6.1.1. 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"
  1. GRB 090715B: Swift/UVOT followup observations
  2. GRB 090715B: break in the optical afterglow decay
  3. GRB 090715B: Enhanced Swift-XRT position
  4. GRB 090715B: Observation of the optical afterglow
  5. GRB 090715B: Swift XRT Refined Analysis
  6. GRB090715B: WHT redshift
  7. GRB 090715B: Swift-BAT refined analysis
  8. GRB 090715B: NOT optical observations
  9. GRB 090715B - Liverpool Telescope Optical Afterglow Candidate
  10. Swift problem fixed
  11. GRB 090715B: Swift detection of a burst with a possible optical counterpart
  12. GRB 090715A: ROTSE-III Optical Limits
  13. GRB 090715: Swift detection of a short hard burst
  14. Detection of GRB 090618 by RT-2 Experiment onboard the CORONAS-PHOTON Satellite
  15. Swift satellite anomaly
  16. GRB090713 optical limit by "Pi of the Sky"
  17. GRB 090712: Fermi GBM observation
  18. GRB 090713: Fermi GBM detection
  19. GRB 090712: Swift-BAT refined analysis
  20. GRB 090712: Swift detection of a burst
  21. GRB 090709A: Xinglong TNT optical upper limit
  22. VLA radio observations of GRB 090709A
  23. GRB 090621B: MTM-500 optical observations
  24. GRB 090709A: deep optical observation with the 10.4m GTC
  25. GRB090709A : WSRT Radio observation
  26. GRB 090709A: Suzaku WAM observation of the prompt emission
  27. GRB 090709A: Swift UVOT upper limits
  28. GRB 090709A: WHT LIRIS observations
  29. GRB 090709B: Fermi GBM detection
  30. GRB 090709A: confirmation of the periodicity in the SPI-ACS data
  31. GRB 090709A: evidence for a very red afterglow at low z
  32. Konus-Wind and Konus-RF observations of GRB 090709A
  33. GRB 090709A: P60 Observations
  34. GRB 090709A: Quasiperiodic variations in the BAT light curve
  35. GRB 090709A: NOT optical observations
  36. GRB 090709A: RAPTOR Limits During Gamma-Ray Emission
  37. GRB 090709A: Swift XRT Refined Analysis
  38. GRB 090709B, Swift-BAT refined analysis
  39. GRB 090709A: Swift-BAT refined analysis
  40. GRB090709A: High Energy BAT/XRT Analysis Suggests Low to Moderate Redshift
  41. GRB 090709A: Wyoming Infrared Observatory NIR upper limits
  42. GRB 090709A, RIMOTS optical upper limits
  43. GRB 090709A: Enhanced Swift-XRT position
  44. GRB 090709A - PAIRITEL Discovery of a Red Afterglow
  45. GRB 090709A: Subaru NIR observation
  46. GRB 090709B: Swift detection of a burst
  47. GRB 090709 : planned Suzaku-ToO observation
  48. GRB 090708 : Fermi GBM detection
  49. GRB 090709: Faulkes Telescope North Upper Limits
  50. GRB 090626: Suzaku WAM observation of the prompt emission
  51. GRB 090709: PAIRITEL NIR Upper Limits
  52. GRB 090704: Fermi GBM observation
  53. GRB 090709: ROTSE-III Optical Limits
  54. GRB 090709: Swift detection of a bright burst
  55. GRB 090708: Early RAPTOR Optical Limits
  56. GRB 090708, Swift-BAT refined analysis
  57. GRB 090708: ROTSE-III Optical Limits
  58. GRB 090708: Swift detection of a burst
  59. GRB 090704: a long GRB found in INTEGRAL off-line analysis
  60. GRB 090706: Fermi GBM detection
  61. Swift-BAT trigger 356516 is not a GRB
  62. Possible GRB090705: Swift-XRT observations
  63. GRB 090705: PAIRITEL NIR Observations
  64. GRB 090705: Swift detection of a possible burst
  65. XRF 090702 : RTT150 optical observations
  66. GRB 090618: Mondy optical observations
  67. GRB 090529: CrAO optical upper limit
  68. GRB 090529: MTM-500 optical observations
  69. GRB 090529: Mt.Terskol optical observations
  70. XRF 090702: Swift-XRT refined analysis
  71. GRB 090703: Fermi GBM detection
  72. GRB 090702: UVOT upper limits
  73. GRB 090313: optical observations
  74. XRF 090702: VLT imaging
  75. XRF 090702: Swift-XRT afterglow position
  76. XRF 090702: a long soft GRB localized with INTEGRAL
  77. GRB 090404: Deep optical imaging and possible host association (correction)
  78. GRB 090404: Deep optical imaging and possible host association
  79. GRB 090701: Fermi GBM detection
  80. GRB 090628: Swift XRT refined analysis
  81. GRB 090630: Fermi GBM detection
  82. GRB 090618: RTT150 optical observations
  83. GRB 090628: Swift/UVOT Upper Limits
  84. Konus-Wind observation of GRB 090626
  85. GRB080628: SAO RAS optical observations
  86. GRB 090628: Swift-BAT refined analysis
  87. GRB090618: 15GHz radio emission faded
  88. GRB 090628: GROND upper limits
  89. GRB 090628: Enhanced Swift-XRT position
  90. GRB 090628: 1.23m CAHA optical observations
  91. GRB 090626: IPN localization
  92. GRB 090628: Swift/UVOT Finding Chart Observation
  93. GRB 090628: Swift XRT position
  94. GRB 090628: Swift detection of a burst
  95. Fermi LAT observations of GRB 090626
  96. GRB 090625B: Fermi GBM observation
  97. GRB 090423: Spitzer observations of the z~8.3 burst
  98. GRB 090625B: Swift/UVOT Upper Limits
  99. GRB 090625B: Swift-XRT refined analysis
  100. GRB 090626: Fermi GBM detection

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