Post by founder on May 1, 2007 15:54:44 GMT -5
2007 Meteor Shower Calendar
Shower Activity Period Maximum Radiant Velocity r ZHR Class Moon
Date S. L. R.A. Dec. km/s
Antihelion Source (ANT) Nov 25-Sep 30 - - - - 30 3.0 3 II -
Quadrantids (QUA) Jan 01-Jan 05 Jan 04 283°16 15:20 +49° 41 2.1 120 I 15
Alpha Centaurids (ACE) Jan 28-Feb 21 Feb 08 319°2 14:00 -59° 56 2.0 5 II 19
Delta Leonids (DLE) Feb 15-Mar 10 Feb 25 336° 11:12 +16° 23 3.0 2 II 8
Gamma Normids (GNO) Feb 25-Mar 22 Mar 14 353° 16:36 -51° 56 2.4 4 II 23
Lyrids (LYR) Apr 16-Apr 25 Apr 22 032°32 18:04 +34° 49 2.1 18 I 5
Pi Puppids (PPU) Apr 15-Apr 28 Apr 24 033°5 07:20 -45° 18 2.0 var III 7
Eta Aquarids (ETA) Apr 19-May 28 May 06 045°5 22:32 -01° 66 2.4 60 I 18
Eta Lyrids (ELY) May 03-May 12 May 09 048.4° 19:08 +44° 44 3.0 3 II 20
June Lyrids (JLY) Jun 11-Jun 21 Jun 16 084.5° 18:32 +35° 31 2.5 3 II 1
June Bootids (JBO) Jun 22-Jul 02 Jun 27 095°7 14:56 +48° 18 2.2 var III 11
Piscis Austrinids (PAU) Jul 15-Aug 10 Jul 28 125° 22:44 -30° 35 3.2 5 II 12
Delta Aquarids (SDA) Jul 12-Aug 19 Jul 28 125° 22:36 -16° 41 3.2 20 I 12
Alpha Capricornids (CAP) Jul 03-Aug 15 Jul 30 127° 20:28 -10° 23 2.5 4 II 14
Perseids (PER) Jul 17-Aug 24 Aug 13 140° 03:04 +58° 59 2.6 100 I 00
Kappa Cygnids (KCG) Aug 03-Aug 25 Aug 18 145° 19:04 +59° 25 3.0 3 II 23
Alpha Aurigids (AUR) Aug 25-Sep 08 Sep 01 158°6 05:36 +42° 66 2.6 7 II 18
September Perseids (SPR) Sep 05-Sep 16 Sep 09 166°7 04:00 +47° 64 2.9 5 II 27
Delta Aurigids (DAU) Sep 18-Oct 10 Oct 04 191° 05:52 +49° 64 2.9 2 II 22
Draconids (GIA) Oct 06-Oct 10 Oct 09 195°4 17:28 +54° 20 2.6 var III 27
Epsilon Geminids (EGE) Oct 14-Oct 27 Oct 18 205° 06:48 +27° 70 3.0 2 II 6
Orionids (ORI) Oct 02-Nov 07 Oct 21 208° 06:20 +16° 66 2.5 23 I 9
Leo Minorids (LMI) Oct 23-Oct 25 Oct 24 211° 10:48 +37° 61 2.7 2 II 12
Southern Taurids (STA) Oct 01-Nov 25 Nov 05 223° 03:28 +13° 27 2.3 5 II 25
Northern Taurids (NTA) Oct 01-Nov 25 Nov 12 230° 03:52 +22° 29 2.3 5 II 3
Leonids (LEO) Nov 10-Nov 23 Nov 19 235°27 10:12 +22° 71 2.5 var III 9
Alpha Monocerotids (AMO) Nov 15-Nov 25 Nov 22 239°32 07:48 +01° 65 2.4 var III 12
Dec Phoenicids (PHO) Nov 28-Dec 09 Dec 06 254°25 01:12 -53° 18 2.8 var III 26
Puppid/Velids (PUP) Dec 01-Dec 15 Dec 07 255° 08:12 -45° 40 2.9 10 I 27
Monocerotids (MON) Nov 27-Dec 17 Dec 09 257° 06:40 +08° 42 3.0 2 II 00
Sigma Hydrids (HYD) Dec 03-Dec 15 Dec 12 260° 08:28 +02° 58 3.0 3 II 3
Geminids (GEM) Dec 07-Dec 17 Dec 14 262°2 07:28 +33° 35 2.6 120 I 5
Coma Berenicids (COM) Dec 12-Jan 23 Dec 20 268° 11:40 +25° 65 3.0 5 II 10
Ursids (URS) Dec 17-Dec 26 Dec 23 270°7 14:28 +76° 33 3.0 10 I 13
Information and Table Template Courtesy the International Meteor Organization.
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Explanation of the 2007 Meteor Shower Calendar
Shower: named for the constellation or closest star within a constellation where the radiant is located at maximum activity.
Activity Period: the dates when the ZHR (Zenith Hourly Rates) are equal to or greater than one.
Maximum: the date on which the maximum activity is expected to occur.
S.L.: the equivalent solar longitude of the date of maximum activity. Solar longitude is measured in degrees (0-359) with 0 occurring at the exact moment of the spring equinox, 90 at the summer solstice, 180 at the autumnal equinox, and 270 at the winter solstice.
Radiant: the area in the sky where shower meteors seem to appear from. This position is given in right ascension (celestial longitude) and declination (celestial latitude).
Velocity: the velocity at which shower meteors strike the Earth's atmosphere. The velocity depends on the angle meteoroids (meteors in space) intersect the Earth. Meteoroids orbiting in the opposite direction of the Earth and striking the atmosphere head-on are much faster than those orbiting in the same direction as the Earth. This speed is measured in kilometers per second.
r: The Population Index, An estimate of the ratio of the number of meteors in subsequent magnitude classes. Simply stated: the lower the "r" value, the resulting overall mean magnitude of each shower will be brighter. "r" usually ranges from 2.0 (bright) to 3.5 (faint).
ZHR: Zenith Hourly Rate, the average maximum number of shower meteors visible per hour if the radiant is located exactly overhead and the limiting magnitude equals +6.5. Actual counts rarely reach this figure as the zenith angle of the radiant is usually less and the limiting magnitude is usually lower. ZHR is a useful tool when comparing the actual observed rates between individual observers as it sets observing conditions for all to the same standards.
Class: A scale developed by Robert Lunsford to group meteor showers by their intensity:
Class I: the strongest annual showers with ZHR's normally ten or better.
Class II: reliable minor showers with ZHR's normally three or better.
Class III: showers with widely variable rates. They may be strong one year and totally inactive the next.
Class IV: weak minor showers with ZHR's rarely exceeding three. The study of these showers is best left to experienced observers who use plotting and angular velocity estimates to determine shower association. Observers with less experience are urged to limit their shower associations to showers with a rating of I to III. These showers are also good targets for video and photographic work.
Moon: the age of the moon in days where 0 is new, 7 is first quarter, 14 is full, and 21 is last quarter. Meteor activity is best seen in the absence of moonlight so showers reaching maximum activity when the moon is less than 10 days old or more than 25 are much more favorably observed than those situated closer to the full moon.
Last Modified: April 30, 2007
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Shower Activity Period Maximum Radiant Velocity r ZHR Class Moon
Date S. L. R.A. Dec. km/s
Antihelion Source (ANT) Nov 25-Sep 30 - - - - 30 3.0 3 II -
Quadrantids (QUA) Jan 01-Jan 05 Jan 04 283°16 15:20 +49° 41 2.1 120 I 15
Alpha Centaurids (ACE) Jan 28-Feb 21 Feb 08 319°2 14:00 -59° 56 2.0 5 II 19
Delta Leonids (DLE) Feb 15-Mar 10 Feb 25 336° 11:12 +16° 23 3.0 2 II 8
Gamma Normids (GNO) Feb 25-Mar 22 Mar 14 353° 16:36 -51° 56 2.4 4 II 23
Lyrids (LYR) Apr 16-Apr 25 Apr 22 032°32 18:04 +34° 49 2.1 18 I 5
Pi Puppids (PPU) Apr 15-Apr 28 Apr 24 033°5 07:20 -45° 18 2.0 var III 7
Eta Aquarids (ETA) Apr 19-May 28 May 06 045°5 22:32 -01° 66 2.4 60 I 18
Eta Lyrids (ELY) May 03-May 12 May 09 048.4° 19:08 +44° 44 3.0 3 II 20
June Lyrids (JLY) Jun 11-Jun 21 Jun 16 084.5° 18:32 +35° 31 2.5 3 II 1
June Bootids (JBO) Jun 22-Jul 02 Jun 27 095°7 14:56 +48° 18 2.2 var III 11
Piscis Austrinids (PAU) Jul 15-Aug 10 Jul 28 125° 22:44 -30° 35 3.2 5 II 12
Delta Aquarids (SDA) Jul 12-Aug 19 Jul 28 125° 22:36 -16° 41 3.2 20 I 12
Alpha Capricornids (CAP) Jul 03-Aug 15 Jul 30 127° 20:28 -10° 23 2.5 4 II 14
Perseids (PER) Jul 17-Aug 24 Aug 13 140° 03:04 +58° 59 2.6 100 I 00
Kappa Cygnids (KCG) Aug 03-Aug 25 Aug 18 145° 19:04 +59° 25 3.0 3 II 23
Alpha Aurigids (AUR) Aug 25-Sep 08 Sep 01 158°6 05:36 +42° 66 2.6 7 II 18
September Perseids (SPR) Sep 05-Sep 16 Sep 09 166°7 04:00 +47° 64 2.9 5 II 27
Delta Aurigids (DAU) Sep 18-Oct 10 Oct 04 191° 05:52 +49° 64 2.9 2 II 22
Draconids (GIA) Oct 06-Oct 10 Oct 09 195°4 17:28 +54° 20 2.6 var III 27
Epsilon Geminids (EGE) Oct 14-Oct 27 Oct 18 205° 06:48 +27° 70 3.0 2 II 6
Orionids (ORI) Oct 02-Nov 07 Oct 21 208° 06:20 +16° 66 2.5 23 I 9
Leo Minorids (LMI) Oct 23-Oct 25 Oct 24 211° 10:48 +37° 61 2.7 2 II 12
Southern Taurids (STA) Oct 01-Nov 25 Nov 05 223° 03:28 +13° 27 2.3 5 II 25
Northern Taurids (NTA) Oct 01-Nov 25 Nov 12 230° 03:52 +22° 29 2.3 5 II 3
Leonids (LEO) Nov 10-Nov 23 Nov 19 235°27 10:12 +22° 71 2.5 var III 9
Alpha Monocerotids (AMO) Nov 15-Nov 25 Nov 22 239°32 07:48 +01° 65 2.4 var III 12
Dec Phoenicids (PHO) Nov 28-Dec 09 Dec 06 254°25 01:12 -53° 18 2.8 var III 26
Puppid/Velids (PUP) Dec 01-Dec 15 Dec 07 255° 08:12 -45° 40 2.9 10 I 27
Monocerotids (MON) Nov 27-Dec 17 Dec 09 257° 06:40 +08° 42 3.0 2 II 00
Sigma Hydrids (HYD) Dec 03-Dec 15 Dec 12 260° 08:28 +02° 58 3.0 3 II 3
Geminids (GEM) Dec 07-Dec 17 Dec 14 262°2 07:28 +33° 35 2.6 120 I 5
Coma Berenicids (COM) Dec 12-Jan 23 Dec 20 268° 11:40 +25° 65 3.0 5 II 10
Ursids (URS) Dec 17-Dec 26 Dec 23 270°7 14:28 +76° 33 3.0 10 I 13
Information and Table Template Courtesy the International Meteor Organization.
--------------------------------------------------------------------------------
Explanation of the 2007 Meteor Shower Calendar
Shower: named for the constellation or closest star within a constellation where the radiant is located at maximum activity.
Activity Period: the dates when the ZHR (Zenith Hourly Rates) are equal to or greater than one.
Maximum: the date on which the maximum activity is expected to occur.
S.L.: the equivalent solar longitude of the date of maximum activity. Solar longitude is measured in degrees (0-359) with 0 occurring at the exact moment of the spring equinox, 90 at the summer solstice, 180 at the autumnal equinox, and 270 at the winter solstice.
Radiant: the area in the sky where shower meteors seem to appear from. This position is given in right ascension (celestial longitude) and declination (celestial latitude).
Velocity: the velocity at which shower meteors strike the Earth's atmosphere. The velocity depends on the angle meteoroids (meteors in space) intersect the Earth. Meteoroids orbiting in the opposite direction of the Earth and striking the atmosphere head-on are much faster than those orbiting in the same direction as the Earth. This speed is measured in kilometers per second.
r: The Population Index, An estimate of the ratio of the number of meteors in subsequent magnitude classes. Simply stated: the lower the "r" value, the resulting overall mean magnitude of each shower will be brighter. "r" usually ranges from 2.0 (bright) to 3.5 (faint).
ZHR: Zenith Hourly Rate, the average maximum number of shower meteors visible per hour if the radiant is located exactly overhead and the limiting magnitude equals +6.5. Actual counts rarely reach this figure as the zenith angle of the radiant is usually less and the limiting magnitude is usually lower. ZHR is a useful tool when comparing the actual observed rates between individual observers as it sets observing conditions for all to the same standards.
Class: A scale developed by Robert Lunsford to group meteor showers by their intensity:
Class I: the strongest annual showers with ZHR's normally ten or better.
Class II: reliable minor showers with ZHR's normally three or better.
Class III: showers with widely variable rates. They may be strong one year and totally inactive the next.
Class IV: weak minor showers with ZHR's rarely exceeding three. The study of these showers is best left to experienced observers who use plotting and angular velocity estimates to determine shower association. Observers with less experience are urged to limit their shower associations to showers with a rating of I to III. These showers are also good targets for video and photographic work.
Moon: the age of the moon in days where 0 is new, 7 is first quarter, 14 is full, and 21 is last quarter. Meteor activity is best seen in the absence of moonlight so showers reaching maximum activity when the moon is less than 10 days old or more than 25 are much more favorably observed than those situated closer to the full moon.
Last Modified: April 30, 2007
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