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"

32541 results found.

  1. GRB040924, RTT150 optical observation
  2. GRB040924,optical observation
  3. GRB 040924: detection of possible host galaxy by Subaru
  4. GRB040924, RTT150 optical observation
  5. GRB040924: KAIT observations
  6. GRB040924: Afterglow magnitude at t=17.5hr
  7. GRB 040924: WSRT Radio Observations
  8. GRB 040924: NIR finding chart
  9. GRB040924 : Optical candidate observations at Lulin observatory
  10. GRB040924 : Optical candidate observations at Lulin observatory
  11. GRB 040924: Subaru NIR observation
  12. GRB 040924: RTT150 optical observations
  13. GRB 040924, optical follow-up
  14. GRB040924: MASTER: OT decay
  15. IPN triangulation of GRB040924 (H3564)
  16. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  17. XRF 040912: Radio Observations
  18. XRF 040916: Radio Observations
  19. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  20. XRF040916: continuing decay of OT
  21. TAROT Observations of GRB 040916 (HETE #3558)
  22. GRB040912(=H3557): Candidate Optical Afterglow
  23. XRF040916, optical observations
  24. XRF040916: Optical Transient Candidate by Subaru
  25. XRF 040912, identification of CXO sources
  26. XRF040916, Ic observations
  27. XRF040916: optical follow-up observations
  28. XRF040912, BVRcIc field calibration
  29. XRF040916, BVRcIc field calibration
  30. GRB040916: Archival optical observations
  31. XRF 040916, optical follow-up
  32. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  33. GRB040916: Optical observations
  34. ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
  35. GRB040916 (= H3558): A Long XRF Localized by HETE
  36. GRB040912 (= H3557): Chandra Observations Scheduled
  37. GRB 040912, BVRI observations
  38. GRB040912 : Kiso Optical follow-up observation
  39. IBAS GRB Alerts 1978-1980
  40. Optical observations of field of GRB040912
  41. GRB040912 (= H3557): A Long GRB or XRF Localized by HETE
  42. GRB040903 - A XRF?
  43. GRB040827: analysis of the XMM-Newton observation
  44. GRB040903, REM near-IR observation
  45. GRB 040903 - INTEGRAL data analysis
  46. Very bright burst detected from SGR 1806-20
  47. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  48. Possible GRB 040903 - further analysis
  49. GRB 040827 - Radio Observations
  50. XMM-Newton Images of GRB 040827
  51. GRB040825A: Optical observations
  52. GRB040825A: Optical observations
  53. GRB 040827: optical and NIR observations at the VLT
  54. GRB 040827: UKIRT - 2nd epoch K-band imaging
  55. GRB 040827: 2nd epoch of Magellan K-band imaging
  56. GRB 040827: K imaging - no evidence of variability
  57. GRB 040827: Detection of NIR afterglow
  58. GRB 040827: Possible detection of optical afterglow
  59. GRB 040827: RTT150 optical observations
  60. MASTER: GRB040827 possible OT
  61. GRB 040825B: Optical observations
  62. GRB040827 optical observations
  63. GRB 040827 - Refined position
  64. GRB040825B, BVRcIc field photometry
  65. GCN GRB OBSERBATION REPORT
  66. GRB040825B: optical observations
  67. GRB040825B (=H3510): An XRF Localized in Real Time by HETE
  68. GRB040825B: Correction to GCN 2657
  69. XRF040812: possible afterglow second Chandra observation
  70. GRB 040812: Second epoch CXO Observations
  71. XRF040812: GMRT observations
  72. XRF 040812: optical observation at VLT
  73. GRB 040812: Optical counterparts of CXO sources
  74. XRF040812: possible afterglow
  75. CXO observation of GRB 040812
  76. IPN/HETE localizations of GRB040810 (=H3489)
  77. GRB 040812: Keck and LCO optical observations
  78. GRB 040812: Keck and LCO observations
  79. GRB 040812: radio observations
  80. GRB040812, optical/IR observations
  81. XRF040701: Optical Observations at ESO
  82. IPN/HETE triangulation of GRB040802 (=H3485)
  83. GRB 040730, infrared observations
  84. GRB 040730: Optical observations
  85. Ongoing activity of SGR 1806-20
  86. GRB040624: optical monitoring at TNG
  87. XRF 040701 - optical observations of the decaying Chandra source
  88. XRF040701: Second-Epoch Chandra Observations
  89. XRF040701: VLA Observations
  90. XRF040701: Magellan Spectroscopy of Chandra Source #2 Associated Galaxy
  91. XRF040701: First-Epoch Chandra Observations
  92. GRB040709 J,H-band observations
  93. GRB040624, optical observations
  94. XRF 040701, optical observations
  95. GRB 040624: optical observations
  96. Optical Observations of GRB040624
  97. GRB 040624: optical observations at TNG and VLT
  98. GRB 040624: R-band observations
  99. GRB 040624, optical observations
  100. GRB 030329: Rebrightening of hyperluminal ejecta.

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