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"

8280 results found.

  1. GRB040511: Redshift identifcation
  2. GRB 040511: Optical limit
  3. GRB040511: Candidate optical/NIR afterglow
  4. GRB 040403: Optical Observations
  5. GRB040323: NIR Observations and Variable Object
  6. GRB 031203: spectoscopic evidence for a 1998bw-like SN
  7. MASTER: RXTE GRB040308 optical observation
  8. RXTE GRB040229 optical observation: no candidate
  9. GRB 040228 Optical observations
  10. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  11. GRB031203: Chandra Observations
  12. GRB040106: Second Epoch Optical Observations
  13. GRB 031220: Optical observations of Chandra X-ray sources
  14. GRB031220 : Optical Observation of Lulin Observatory
  15. GRB 031203 I-band monitoring
  16. GRB 2974 follow-up observations
  17. GRB 021203: A Normal GRB viewed far off axis?
  18. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  19. GRB 031111: Optical observations
  20. SN 2003jd (SN/GRB?) - possible association with GRB 030929
  21. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  22. GRB030913: Subaru Optical Observations
  23. GRB030913, candidate afterglow observations
  24. GRB 030913, optical candidate
  25. GRB 030824: Candidate Follow-Up
  26. XRF030824: optical observations
  27. XRF030824: Palomar observations
  28. GRB 030824: Candidate Afterglow (or Variable/Flare Star?)
  29. RAPTOR observations of GRB030823
  30. Summary of recent IPN and HETE detections of SGR bursts
  31. GRB 021206 Optical Observations
  32. GRB030725: Optical observations
  33. XRF030723: Re-analysis of ROTSE-III early images
  34. GRB030725, optical transient observations
  35. XRF 030723: VLT spectra
  36. XRF030723: Palomar observations and proposed counterpart
  37. GRB030725 (=H2779): A Bright GRB Localized by HETE
  38. RXTE PCA Observations of SGR1806-20 Region
  39. GRB 021206, Radio afterglow candidate
  40. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  41. GRB 030519B: optical observations.
  42. GRB 030528: Optical observations at RIKEN
  43. GRB 030329: HST ACS Observations of the Host
  44. GRB030324: Further Observations of the Candidate Optical Afterglow
  45. GRB 030418: Second Epoch Optical Observations with Magellan
  46. GRB030429: RTT150 optical observations, a possible host galaxy
  47. GRB030329: RTT150 optical observations and upper limit for a host
  48. GRB 030429: IR photometry with IRSF/SIRIUS
  49. GRB030501: TAROT candidate afterglow present in archival images
  50. GRB 030501: TAROT possible candidate counterpart
  51. GRB 030429: confirmation of afterglow candidate
  52. GRB030429, possible optical counterpart
  53. GRB 030429: ROTSE-III observations
  54. GRB030329, SPM optical observations
  55. Optical Observations of GRB 030418 with Magellan
  56. GRB 030418: Optical afterglow
  57. GRB 030418: Finder for afterglow candidate
  58. GRB 030418: Optical afterglow candidate
  59. GRB030324: Candidate Optical Afterglow (Erratum)
  60. GRB030324: Candidate Optical Afterglow
  61. GRB030329: HET spectroscopic monitoring
  62. GRB 030329: precise position from Kyoto images
  63. GRB 030329: Optical afterglow fading
  64. GRB 030329 follow-up
  65. GRB 030329: Optical afterglow candidate
  66. GRB 030329: OT candidate
  67. GRB 030329: Optical afterglow candidate
  68. GRB 030328: Finding chart
  69. GRB 030328: Optical afterglow candidate
  70. GRB030324 optical observation
  71. GRB030131, BVRcIc field photometry
  72. GRB030324, optical observations
  73. GRB030324, optical observations
  74. GRB030323: V, R, I photometry
  75. VLT/FORS2 spectra of GRB 030323
  76. GRB030323, ROTSE-III detection of possible optical counterpart
  77. GRB030323, optical observations
  78. GRB030323, possible optical counterpart
  79. IPN upper limit to a GRB associated with SN2003L
  80. GRB 030227 optical afterglow
  81. GRB 030227: Confirmed Optical Afterglow (S1-A)
  82. GRB 030227: fading of candidate optical afterglow 'S1-A'
  83. GRB 030227, possible optical counterpart of XMM-Newton source
  84. GRB030227 - faint tentative OT candidate
  85. GRB 030226: Optical afterglow
  86. GRB030226: Candidate optical afterglow
  87. GRB: Non-Referencing of GCN Circulars.
  88. GRB 030131: marginal optical detection
  89. GRB030131: Candidate Optical Afterglow
  90. GRB 030131, optical observations
  91. GRB030131: Kiso optical limit for corrected position
  92. GRB030131: Optical limits for corrected position
  93. GRB 030131: afterglow candidate
  94. GRB 020819: afterglow candidate
  95. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  96. GRB030115 submm upper limit
  97. GRB 030115: Further IR observations with IRSF/SIRIUS
  98. Publicizing GRB Discoveries - A Message from NASA HQ
  99. GRB 030115: Radio detection of IR candidate
  100. GRB 030115: IR observations with IRSF/SIRIUS

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