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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

22211 results found.

  1. GRB 250101A: OASDG optical observations
  2. Fermi GRB 250101B: Global MASTER-Net observations report
  3. GRB 250101A: SAO RAS observations of optical brightening
  4. GRB 250101A: SAO RAS optical observations
  5. GRB 250101A: SVOM/C-GFT early optical observations
  6. LIGO/Virgo/KAGRA S250101k: Upper limits from Fermi-GBM Observations
  7. GRB 250101A: MASTER earlier OT observations with SOSS emission features
  8. GRB 250101A: Nanshan/HMT optical observations
  9. GRB 250101A : GIT optical detection
  10. Swift GRB250101.56: Global MASTER-Net observations report
  11. GRB 241217a/EP241217b: ATCA Radio Detection
  12. EP241217a: VLA Radio Detection

  13. LIGO/Virgo/KAGRA S241231du: Coverage and upper limit from MAXI/GSC observations
  14. GRB 241229B: Continued CrAO ZTSh observations
  15. LIGO/Virgo/KAGRA S241231bg: Updated NED Galaxies in the Localization Volume
  16. LIGO/Virgo/KAGRA S241231bg: NED Galaxies in the Localization Volume
  17. GRB 241229A: EP-FXT X-ray afterglow confirmation
  18. GRB 241228B: Multiband optical monitoring with 1.6m Mephisto
  19. EP241217A: J band upper limit by SYSU 80cm telescope
  20. GRB 241228B: SAO RAS optical observations
  21. GRB 241229B: CrAO ZTSh possible optical counterpart of SVOM/VT confirmation
  22. GRB 241229A: SAO RAS optical observations
  23. GRB 241229B: SVOM/VT optical candidate
  24. GRB 241229A: Swift-XRT observations
  25. EP240702a: 7DT Optical upper limits
  26. GRB 240606B: 7DT Optical upper limits
  27. Fermi trigger No 757231333: Global MASTER-Net observations report
  28. GRB241229B: UVOT upper limits
  29. GRB 241228B: D50 optical detection
  30. GRB 241228B: Fermi GBM Observation
  31. GRB 241228B: Swift-XRT afterglow detection
  32. GRB 241229A: Swift ToO observations
  33. GRB 241229B: NUTTelA-TAO / BSTI Optical Limits
  34. GRB 241228A: Mondy optical afterglow observations
  35. IceCube-241224A: No transient candidates from the Zwicky Transient Facility
  36. Swift GRB 241229B: Global MASTER-Net observations report
  37. GRB 241229A: GOTO optical upper limits
  38. GRB 241228A: NOT optical upper limits
  39. GRB 241228B: LCO optical observation
  40. GRB 241228B: Swift/BAT-GUANO localization skymap of a burst
  41. Fermi GRB 241228B: Global MASTER-Net observations report
  42. GRB241228B: GROWTH-India Telescope optical observations
  43. Swift GRB 241228A: Global MASTER-Net observations report
  44. GRB 241228B: LCOGT photometry of the likely optical counterpart GOTO24jmz
  45. GRB 241228B: GOTO24jmz optical follow-up observations
  46. GRB 241226A: Swift/BAT-GUANO localization skymap of a burst
  47. GRB 241228B: Swift ToO observations
  48. GRB 241228B: TRT optical counterpart confirmation
  49. GRB 241228A: Swift/UVOT Upper Limits
  50. GRB 241228B: GOTO possible optical counterpart candidate
  51. GRB 241217A/EP241217b: continued SOAR observations
  52. Fermi GRB 241226A: Global MASTER-Net observations report
  53. EP241223a: Mondy AZT-33IK optical observations
  54. GRB 241029A: LCO optical observation
  55. GRB 241223A: Swift-XRT observations
  56. GRB 241029A: AbAO AS-32 optical observations
  57. Fermi trigger No 756678579: Global MASTER-Net observations report
  58. IceCube Alert 241224.30: Global MASTER-Net observations report
  59. EP241223a: Global MASTER-Net observations report
  60. EP241223a: EP-WXT detection of a fast X-ray transient
  61. EP241113a: Non-detection in Radio Follow-up Observations with eMERLIN
  62. GRB241113A: 7DT Optical upper limits
  63. Fermi GRB 241223A: Global MASTER-Net observations report
  64. GRB 241223A: GOTO optical observations summary
  65. GRB 241105A: JWST photometric observations of the host galaxy
  66. GRB 241223A: Swift ToO observations
  67. EP241217a: e-MERLIN radio observations
  68. GRB 241217A / EP241217b: Non-detection in ATCA Radio Follow-up Observations
  69. Fermi trigger No 756447119: Global MASTER-Net observations report
  70. Fermi GRB 241221A: Global MASTER-Net observations report
  71. EP241021a: VLA radio detection
  72. GRB 241218A: Mondy AZT-33IK optical upper limit
  73. EP241217a : Leavitt Observatory optical upper limit
  74. GRB 241217A/EP241217b: tentative VLT spectroscopic redshift z=1.879
  75. EP241217a: 1.6m Mephisto multi-band optical observations
  76. GRB 241217a/EP241217B: 1.6m Mephisto optical upper limits
  77. GRB 241218A: Swift/UVOT Upper Limits
  78. GRB 241218A: NOT optical upper limits
  79. EP 241217a: NIR detection with P200/WIRC
  80. EP 241217a: Possible J-band detection with WINTER
  81. EP241217a: refined EP-WXT analysis and EP-FXT follow-up observations
  82. GRB 241217A / EP241217b: Nanshan/HMT optical upper limit
  83. GRB 241217A: refined SVOM/MXT data analysis. Long lasting X-ray emission.
  84. GRB 241217A / EP241217b: NOT optical upper limits
  85. GRB 241218A: REM optical upper limit
  86. GRB 241217A/EP241217b: REM optical/NIR upper limits
  87. EP241217a: REM optical/NIR upper limits
  88. EP241217a: Liverpool Telescope optical follow-up
  89. EP241217a: NOT optical observations
  90. EP241217a: GROWTH-India Telescope optical observations
  91. GRB 241218A: NUTTelA-TAO / BSTI Optical Limits
  92. EP241119a: 7DT Optical upper limits
  93. EP241217b: Global MASTER-Net observations report
  94. GRB 241209A: ATCA radio follow-up observations
  95. EP241217a: Xinglong optical follow-up observations
  96. EP241217a: Global MASTER-Net observations report
  97. GRB 241217A : SVOM/VT optical afterglow detection
  98. GRB 241217A: Swift-XRT afterglow detection
  99. GRB 241217A: GRANDMA/TAROT optical upperlimits
  100. EP241217a: Swift-XRT Detection

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